Human Interaction with the Environment
This is the exciting schedule of topics whic will be discussed as Erden is at sea, hitting some of these topics head-on.....
Click on one of the language tabs in the upper right corner to see each week's new Education Program, based on the schedule of topics, in English, Chinese and Spanish - and, the first expedition in the world to ever have ongoing education, tri-lingually! Get engaged, sit back enjoy, learn, and spread the word. You're part of history! Click here to see our Content Release Schedule.
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Westbound Rower Education Week 1: What are Plastics? How are Plastics Made? What is Going on with Plastics?
Now imagine for a second. What would a world look like without plastics?
Well, most objects around you would probably not be there, or perhaps would be made from another material. This is because plastic is everywhere, we cannot escape it and there are reasons for that. Plastic is an amazing material, and it has made our lives much cleaner, safer and generally more enjoyable. It is in electronics, heathcare, buildings and food packaging, not to mention train, planes, automobiles, and of course, Erden’s boat! The list goes on, making plastics often regarded as a “Top 10: Most Important Chemically Engineered Inventions” of the modern times.
We don’t exactly know who came up with the word for plastics, but we know the word plastics is rooted to the Greek word Plastikos, that means “fit for moulding” or a “lot of different uses”. Can you see the connection now? You may have heard at some point that most plastic is made from fossil fuel (unless from biomaterials), and it is! But have you ever wondered how the thick and black liquid that is oil can be turned into a transparent water bottle? Let’s follow the journey of crude oil to a plastic bottle.
Crude oil is first extracted and pumped from deep underground, where it was originally made from ancient and dead organic matter that got turned into oil under extreme heat and pressure as it has been buried deeper with time. The extracted oil is then shipped to a refinery, where the oil is separated into different layers of and fuels. This is how we get fuels like petrol, kerosine (jet fuel), and diesel. You can see what these gets separated in these oil refineries in the graphic below!
Graphic 1: Fractional distillation of crude oil
Graphic 2: Plastic Resin Identification Code
For Plastics, we are interested in the second layer (Naphtha). Naphtha is again put under extreme pressures to break them down further into single molecules. Millions of these tiny molecules are then connected to form polymer under a chemical process called polymerisation. Plastic factories turn these polymers into granules or pellets that are later heated and moulded into a shape of a plastic bottle that now holds your drinking water!
Plastic bottles are often made from PET (or PETE), or number 1 on the plastic resin identification code. Other products require different plastic resins, but the process of how it is made is conceptually similar to how plastic bottles are made. You will have probably noticed these symbols on many things you find at the store and your home, these are designed so sorting plastic waste can be done from home with ease, and also helps recyclers ensure that the recycled plastic is as homogeneous as possible so it can be reused again.
As you can see, seven types of plastic resins are used in general household items, but this doesn’t mean there are only seven types of plastics made. Some plastics have additives in them, and they make the plastic better at their job, for example to be “stretchier,” to be stiffer, to be resistant to heat and so on. When all of these additives are involved, it is estimated there are more than 40,000 ways plastic products are made. Yikes, and Wow! To fulfil how we live, and for society to run, we need a lot of plastics; and it just so happens we create a lot of plastics to suit our needs. Last year global estimates of all plastics produced came to roughly 365 million metric tons, that is about one million metric tons each day, or about 166,667 average sized African Bush Elephants!
Graphic 3: Plastic Recycling Worldwide
In an ideal world, plastics are used, we as consumers sort the waste into the “plastics bin”, it gets picked up, it gets processed and recycled, and then the recycled plastics are turned back into plastic products we use. This is the continuous cycle (Circular Economy) we all hope to achieve with plastics. Unfortunately, only a small fraction of this plastic is recycled, only 9% globally, but it varies country-by-country with India leading the global plastic recycling race with 60%. While the European Union shows a 30% plastic recycling rate, some countries like Lithuania boasts a plastic recycling rate of 74% (from 2019). In weeks to come, we will spend some time discussing some of the roadblock and solutions to increase plastic recycling globally.
The good news is that not all the remaining 91% of plastic produced are fated to end up in the ocean or dumped in landfills where the plastics may take hundreds of years to naturally break down. A way municipalities and countries currently deal with plastic and other municipal waste is to turn the waste into energy. The production of energy from waste tackles two problems, like the shrinking available spaces for landfilling, and adding some value to the waste. However, as waste to energy requires that the waste is burned, it has a host of environmental issues on its own related to climate change, and landfills are still required to remove the remnant ash. These issues will be discussed more thoroughly in the coming weeks. Due to the related issues we find with current waste management systems, it therefore makes recycling and the creation of a circular economy for plastic all the more important. This requires support from the government, industry, the society and yourself (as the consumer) to achieve.
On the other hand, the plastics which are mismanaged “fall through the cracks” and do not end up where they need to go to be recovered or contained. Via wind and rain, plastic waste can fall into streams and rivers, most of which ultimately flow into the ocean. As we will see in the coming weeks, plastic pollution in the ocean can have disastrous effects for species in the ocean, land, and the air. We will also look at how plastic pollution can be used to bring communities together, to remove plastics flowing into the ocean, and effectively allowing us to “turn off the tap” of plastics entering the ocean. We will leave you this week with this cool video on how expanded polystyrene is made.
How It's Made - Expanded Polystyrene Products
You can also always track Erden's Live Westbound Rower Route here as well!
Westbound Rower Education Week 5: How Does Plastic Enter the Ocean? And Where Does it go From There?
In the past few weeks, we have discussed both how much plastic is made and how it is made, and then we established that some portion of mismanaged plastic can end up as pollution in our ocean. "Mismanaged," meaning plastic that falls through the cracks of establish waste management strategies, like recycling, waste to energy or landfill. When mismanaged, plastic could end up in drainage ditches, illegal landfills, burned or left discarded on the side of the street. All these scenarios increase the probability of plastic entering the ocean.
What happens when plastic ends up in the ocean? Before we answer that question, a few important background questions should be addressed: How much plastic is already in the ocean? How much plastic is being added each year? And how does it end up in the ocean in the first place?
Some studies suggest there is already about 150 million tonnes if plastic in the ocean. To visualise how much that is, imagine the entire length of the world’s coastlines, all 1.16 million kilometres of it. If the 150 million tonnes of plastic were piled up evenly on land, there would be a 1.2-metre-tall wall separating us from the ocean. That’s a lot of plastic.
The net gain in plastic in the ocean each year is not only problematic, but also something we don’t want to hear, because it is like a sink overflowing if we intentionally don’t turn off the tap. Each year it is estimated some 8 million tonnes of plastic waste ends up in the ocean. That’s nearly the weight of 90 aircraft carriers. Using the African Bush Elephants example from a couple weeks ago, about 3650 elephant’s weight worth of plastic enters the ocean in a single day! A few studies estimate that if the rate of plastic entering the ocean remain constant, the amount of plastic in the ocean could double by 2040. Hopefully, we do not get to that point, and when we move on to topics on potential solutions, we can see how there is an unexplored goldmine of opportunity in preventing plastic entering the ocean.
Above: Infographic on ocean plastic entering the ocean
Plastic enters our waterways, and consequently, our ocean. Lighter plastic, like plastic bags and films could be blown to the water. If left mismanaged, precipitation events and floods can carry plastics to the water. Some cities have such an extreme problem with this that plastic blocking up storm drains caused flash floods, that damaged city infrastructure and in come cases people even died. We ourselves could also unintentionally drop plastics in the water. Unfortunately, it all leads back to us, making the ocean plastic problem our common problem. Remember very single piece of plastic has left someone’s hand before it becomes waste, and there is nobody directly to blame, but in fact, all of us are at fault, as we all use it.
As you probably already know, most plastic enters the ocean from land, up to 80% in fact. Most of which enters the ocean through waterways (creeks, streams, rivers etc.) that all eventually drain into the big blue saline reservoir – the Ocean. With the edge of this reservoir being the global coastlines, and knowing that all waterways are connected, there is argument we should expand our understand of coastlines to include the banks of all creeks, rivers and streams on the planet. Imagine how big the “coastline” would be then! If we think of it this way, there is a holistic approach to preventing plastic entering any body of water.
Above: Using nets to capture plastic flowing in a river in Cambodia
The other 20% of plastic in the ocean is estimated to come from plastic that is dropped at sea, such as discarded or lost fishing nets, or ghost nets. The are given this name because they continue to kill animals that gets trapped in them, and they even look like giant ghosts too! Dumping of any type of waste is technically illegal, but given the vastness of the ocean, it is hard to catch the culprits and enforce the related fines and penalties. At the end, we all end up paying for these undesirable behaviours in the form of polluted waters, damaged ecosystems, contaminated fish, and negative effects towards tourism to name a few. Again, repeating from before, there is nobody directly to blame, but in fact, all of us are at fault, as we all use it.
Where plastic ultimately ends up in the ocean is again influenced by many aspects, and it is also why there are difficulties in scientifically estimating the total amount of plastic in the ocean. The first factor is the density of plastics. Because not all plastic floats at the surface! Some plastic can sink to the bottom, or even be suspended in the water column (somewhere between the surface and the ocean floor). Let’s look at the graph above. A value of 1.00 means the plastic has the same density seawater. Anything below 1.00 means that it will float on the surface, and anything above 1.00 means that it will be suspended in the water or sink to the bottom. Today, plastic can be found in all parts of the ocean, even in the deepest part of the Marianas Trench, which is the deepest known location in the ocean.
Above: Density comparison of common plastic resin with seawater
Once plastic get into the ocean, whether it is suspended or on the surface, it can travel the world with the ocean currents, like getting a free ride around the world. You have probably heard of the Great Pacific Garbage Patch, or the North Pacific Gyre which unfortunately got its fame from the fact it is a large circulating body of water, like a huge whirlpool, which has plastic from Asia and North America, trapped in this huge swirling system of currents. The North Pacific Gyre, measuring up to thrice the size of France with a surface area of 1.6 million square km. There are five ocean gyres in the ocean, two in the Pacific and Atlantic (North and South) and one in the Indian ocean basin. We will discuss how ocean gyres and ocean currents work together to gather ocean plastic next week, but for this week, you now know that these are areas where plastic from anywhere in the world can potentially end up.
The good news is that you can make a difference. You can pick up plastic when you out on a walk, in parks, hikes, and of course near any bodies of water. You can show others that you care with action, and not waiting for someone else to clean things up. You can also help by reporting trash hotspots in our waterways anywhere in the world using our Global Alert app, from Ocean Recovery Alliance, now available on IOS and Android. The power of citizen science and Global Alert allows you to “See, Share and Solve” when plastic hotspots are identified, and users can take photos, geotag the hotspot and provide valuable information for others in the region to understand the problem and where the problem is. To take it a step further, the data can be used to plan clean-up and prevention measures.
We highly encourage everyone to download and try out our Global Alert App. Play around with it first and check out its features! We at the Westbound Rower Education Program will have a week to feature this awesome platform, teaching all how to effectively use the platform and make a change by locating plastic hotspots near where you live!
Westbound Rower Education Week 8: How Plastic Breaks Down
If you thought the only thing plastic did in the ocean is move around the world with ocean currents and into ocean gyres, well that’s just part of the story. Plastic in the ocean is the cause of many hazardous and ecological damaging effects, many of which get more complicated when plastic breaks down once it is released into the environment.
We desire plastic for its durability, lightness, ease of use among other things, but creating something that is super durable has its drawbacks. Plastic can stay in the ocean for a very long time if it gets into the ocean. Some studies suggest it takes up 450 years for plastic to gradually break down because of the resistant nature of the chemicals and other additives. Furthermore, with most plastic still made from synthetic materials, it cannot decompose. Meaning it is not naturally recycled or absorbed by nature with the help of the FBI (Fungi, Bacteria, and invertebrates). Instead, plastic can be mechanically and chemically broken down, but the plastic will still be present in the environment in one form or another. All types of plastic, big or small, can have harmful and direct impacts on marine biota.
What does plastic break down into? Perhaps we should first take a step back and discuss how we classify plastic when it is in the ocean. Most ocean plastic that is visible to the naked eye by both humans and other marine life will be macroplastics (large pieces of waste or litter). The size range of macroplastics is extremely varied, and any pieces of plastic pollution larger than 5mm are scientifically considered macroplastics. This means that plastic ranging from the size of a cornflake to that of a giant entangled ghost net, are all macroplastics.
It doesn’t get much easier to judge either when we look at microplastic, because this includes all plastic smaller than 5mm in size, which means that it could be the size of a single cornflake, or down to microscopic fibres that require the most microscopes to see. However, macroplastic and microplastic are both plastic, an element that simply does not belong in our ocean, so effort is needed to take it out, or of course, prevent it from going in in the first place!
All plastic will face degradation in the polymer chain in one way or form when exposed to the elements, and all plastic can eventually be broken down into microplastics. The environmental and health responses to microplastic are still an unknown and are being studied by many scientists, but that should not be a reason for inaction and stopping plastic input into the ocean as we continue to learn of its dangers to the environment. This way of cautious thinking and responding to environmental issues is the precautionary principle (meaning that no large action is taken until many studies are undertaken to fully prove “cause and effect”). This principle can be applied to most environmental concerns we are facing, and will face in the future, and sadly it often causes us to lose time on simple solutions. Plastic is not natural in the environment, so it should not be on our streets, parks waters and sea, and there is no need to study the simple fact that litter and waste are not natural.
Plastic, like all other materials, can be impacted by photodegredation. This is the process of a material being degraded by sunlight, more specifically ultraviolet (UV) light. Since plastic properties can be altered with additives, however, plastic bottles for example, often include a chemical UV stabiliser. These additives absorb and scatter UV radiation, therefore adding a layer of protection to the product, while increasing the product’s life cycle and resistance to degradation by UV.
Humans are also affected by UV exposure, but instead of breaking down into smaller pieces we get sunburnt! So next time you are out, remember to apply a layer of sunscreen! Erden has a lot of experience with the sun being at sea, in the tropical zones, for long periods of time.
Going back to plastic, even with these additives, plastic will eventually still be affected by sunlight. To summarise the photodegradation process, it is generally speaking the first step in the natural degradation process for plastic. Exposure to the sun and the UV radiation provides the necessary energy to incorporate an oxygen atom into the plastic polymer chain, degrading and breaking the polymer chain at the molecular level. The result of this photo-oxidation process causes the plastic to become brittle, and susceptible to smaller and smaller pieces when exposed to physical forces from the ocean, waves, wind, salt and animals. This entire process is very slow, and it may take up to 50 years for plastic to photodegrade to a crumbling state. In the water, photodegradative effect is further decreased because of the lower temperature and oxygen availability. But once the plastic has been broken down to the ingestible and microscopic scales, that is when plastic can cause much more damage to marine species, and even to our own health.
Above: Demonstration of the brittleness of a photodegraded plastic bottle.
Colour of the plastic can also be lost in the process, with the colour fading away with time. This process can also be found on some plastics in your own house, or the paint on your wall behind a painting. The yellow tint on some older plastic appliances or the shadow that fits your painting on the wall is the result of just exposure to light. Check out this video of an old and discoloured videogame controller getting restored to its original colour!
Above: Video of removing the yellowing from old plastic
In the coming weeks, in the Westbound Rower Education Program, we will also discuss how plastic attracts and toxic chemicals when in the ocean, and releases toxic additives from the plastic resin. How can plastics serve as a vessel for potentially invasive species, and how it can be ingested or entangle marine life. In another lesson, we will also discuss case studies of how the visual impact of plastic pollution has affected coastal tourism in many of our communities around the world.
Westbound Rower Education Week 9: Plastic Sorption of Chemicals
Above: Overview of Plastic Interactions in the ocean
Plastics and Microplastics has been known to accumulate certain chemicals like persistent organic pollutants, metals and leach chemical additives that were added during the plastic production process. All of the pollutants that gather around plastic, particularly in salt water, where the pollutants don’t like water (much like oil and water don’t mix), raises the concentration of toxic chemicals in the vicinity, raising concerns as plastic can serve as a method of transport for xenobiotic chemicals over long distances and into the bodies of marine organisms. This phenomenon does not happen with plastic on land, because there is no presence of these toxins in the water.
So how does plastic attract these pollutants towards itself? Find out on this week’s Westbound Wednesday!
Persistent Organic Pollutants are synthetic chemicals that are very resistant to environmental degradation, allowing them to accumulate in different environments for a long period of time. Just like plastic. But unlike plastic, these synthetic chemicals can be metabolized in the bodies of animals, including us! This makes it a global health concern, as the potential for human and environmental toxicity from POPs has been scientifically realized. There are many categories of POPs, but in plastic, much of the research focus has been on Polycyclic Aromatic Hydrocarbons (PAHs), Polyhlorinated Biphenyls (PCBs), and Polybrominated Diphenyl Ethers (PBDEs).
Above: Short video on POPs
PAHs are a large group of over 100 chemicals, but all PAHs are composed of more than two or more benzene rings in its structure. As these chemicals are hydrocarbons, they are associated with fossil fuels and occur naturally in coal, oil, natural gas, and even wood. They can be released into the air when fossil fuels are burned, so in nature the only sources of PAHs are forest fires and volcanoes, leaving most of the PAH released as a result of our fossil fuel consumption.
PCBs are a group of man-made organic chemicals that is made up of chlorine, carbon and hydrogen atoms. The physical and chemical properties are determined by the number and position of chlorine atoms in the molecule and they have no smell or taste, and can vary from an oil to a waxy solid. It was once used as an industrial compound but was banned in 1979 when the potential for adverse effects on animal and human health.
PBDEs are another class of organic pollutant that is used as a flame retardant in the plastic production process; these chemicals have also been used in building materials, vehicles, and textiles. Instead of having chlorine atoms, it has bromine atoms attached with its congeners determined by the number of bromine atoms.
Metals have also been found to sorb with plastics in the environment. When we talk about these metals, we are talking micronutrient amounts, and any alteration and changes in exposure can have detrimental effects on health. For example, our organs may fail when we are exposed to high concentrations of lead, mercury, arsenic and cadmium.
Above: Sorption mechanisms observed in plastics
Sorption is the process where solutes are removed from the solution onto a mineral surface. In plastics, POPs (solutes) are “removed” from the sea water towards the surface of plastic and microplastics. Scientists have found 4 main mechanisms that allow for chemical sorption to occur. The mechanisms include. Hydrophobic, and Electrostatic Interactions, Pore Filling, Hydrogen bonding.
PAHs have been observed to sorb by hydrophobic interactions. Because both are non-polar on the surface, they attract. Electrostatic interaction occurs on the molecular level, when particles have different charges they attract, so a positively and negatively charged particle attracts, behaving a little like magnets. Hydrogen bonding is more of an attractive force than a bond between slightly charged molecules. The addition of oxygen into the plastic molecule during the photodegradation process can form functional groups that can form hydrogen bonds with hydrogen bonding chemicals significantly enhancing sorption capacity. When the plastic polymer breaks down, pores, cracks and holes are all potential locations where chemicals and metals in the water can be filled up, clinging onto microplastics
All of these sorption interactions are easy to break, and chemicals, metals and other pollutants can be adsorbed to the plastic surface, then released back into the water when the means of adsorption breaks. This continual cycle of interactions will continue to gather and attract POPs to plastics in the ocean.
A quick update on Erden:
Erden is now fairly close to Waikiki, in Hawaii, and expects to be there perhaps the first week of September. His short delay was due to his “Dance with Linda”, Linda being the Tropical Storm that is between him and Oahu, rowing north to let Linda pass below and deploying his para-anchor to reduce the windrift. A more detailed account can be found on Erden’s Blog!
Westbound Rower Education Week 12: Greenhouse Effect and the “Enhanced Greenhouse Effect”
Erden arrived at Waikiki Yacht Club in Hawaii on 12th September (or 11th September Hawaii time)! Now, at his pit stop, he will resupply and repair a few components of his rowboat before setting off, Hong Kong-bound on the 1st October. So for those who like to watch Erden’s tracking “dot” there won’t be anything too interesting going on over the next few days.
So far, since his launch from Crescent City, California, Erden has spent 80 days at sea, but could have made it sooner if he was not delayed by the Southwest Winds in the first few weeks, and his “dance with TS Linda” closer to Hawaii. Both of these wind and weather effects are related to the changing climate and subsequently the weather patterns and as, and we will look a little deeper into that today.
In the past couple of decades, meterologists and climate scientists have observed changes in seasonal climate patterns and extreme weather events, like hurricanes, over time. These changes in patterns we now call Climate Change. We cannot confuse the terms Climate Change and Global Warming because they are describing two separate things. Global Warming typically refers to the anthropogenic heating of the Earth since the 1800s. Climate Change describes the larger scale changes in the Earth’s climate at a much longer geological time scale. Where the two come together is the current situation, as the climate has been changing at an unprecedented rate because there is more energy trapped within the Earth’s system, enhancing the Greenhouse Effect, which also leads to global warming.
It is very much a chicken or the egg situation, they simply come together.
Above: Comparison of atmospheric carbon dioxide and temperature
So how is the Greenhouse Effect being enhanced? To simply put it, the greenhouse effect is being enhanced by the overall impact of human activities, which is increasing the concentration of greenhouse gases in the atmosphere. To fully understand how this process works, we must first understand the greenhouse gases and the natural greenhouse effect.
Greenhouse gases are gases in the atmosphere that absorb and emit radiation and heat, largely in the infrared range which is emitted by the Earth. Some of these gases are naturally occurring like water vapour, carbon dioxide, methane, nitrous oxide and ozone. This is rather self-explanatory, as water vapour is the gaseous form of water, carbon dioxide is released naturally by most living things, methane can be a product of decomposition, nitrous oxides can be released from natural fires and volcanoes, and ozone is naturally formed by UV interactions with molecular oxygen in the atmosphere.
Together, over the last many millions of years, these natural greenhouse gases in the atmosphere kept the average temperature on the planet at about 14.0 degrees Celsius (57.2 degrees Fahrenheit) this temperature is not too cold, nor too hot, to support life. When the Earth receives energy from the Sun, the Earth also emits some energy of its own. An example of when there is too much greenhouse gas in the atmosphere is Venus, which has a scorching temperature of 462 degrees Celsius (864 degrees Fahrenheit). And as we know, there is no life there.
The complex interactions between the Earth emitted longwave radiation and greenhouse gases in the atmosphere are complex, so we will talk about this on the surface level, and assume greenhouse gases act as “black bodies.” A “black body” is a material or substance that releases all radiation that it absorbs, essentially making the net energy balance zero. With this assumption, a proportion of radiation emitted from the Earth can be absorbed by the greenhouse gas, and then released in all directions. The Earth emits what is commonly known as longwave radiation that can be seen in the infrared range. We also emit radiation in this range and it is how your temperature gets checked at the airport!
Above: Infrared image of a city street
Some of the longwave radiation is directed off into space, and some is directed to the surface, thereby trapping a proportion of the heat within the Earth’s atmosphere. Horizontal movement of radiation is also possible, and the effects can be compounded with radiation being absorbed and released in all directions, again by greenhouse gases.
Unlike longwave radiation, shortwave radiation from the Sun penetrates our atmosphere, so it freely enters and leaves the Earth’s system. In the graph below, you can see how greenhouse gases are better at absorbing radiation of certain wavelengths. Each greenhouse gas has a slightly different peak wavelength of absorption, working together to produce a climate suitable for life.
Above: Greenhouse Gases wavelength absorption peaks
The enhanced greenhouse effect works pretty much the same way. Only the concentration of greenhouse gases is increased from human activities like energy production, agriculture, transportation, urbanisation and rapid consumption of the Earth’s finite resources. The volume of the naturally occurring greenhouse gases has increased dramatically from pre-industrial periods (1750s), for example Carbon Dioxide concentrations increased by 147%, Methane concentration increased by 259% and Nitrous Oxides concentration increased by 123%. Water content in the atmosphere, water vapour, tends to stay fairly stable despite the observations of increased precipitation. One explanation for this is that the hydrological cycle is speeding up with climate change, though more research is needed in this area. Collectively, these levels of greenhouse gases are unprecedented in the past 800,000 years.
Industrial activities further introduce new greenhouse gases into the atmosphere like Hydrofluorocarbons (HFCs), Cholorfluorocarbons (CFCs), Petfluromethane (CF4), and Sulfur hexafluoride (SF6). These gases can be released from electronics, refrigerants, electrical insulation and metal production. CFCs have also been known to damage our ozone layer, leading to the Montreal Protocol which banned the substance in 1987.
Above: concentration change atmospheric carbon dioxide
With all the greenhouse gases out there, which is the most important? Or which is likely to do the most damage and trap the most heat? This is where the value of Global Warming Potential (GWP) comes in. GWP was developed as a way to compare the global warming impacts of different greenhouse gases in a 100-year horizon. Based around Carbon Dioxide, the GWP value of carbon dioxide is 1.0. Larger values means the greenhouse gas has a larger potential or impact on our climate over the 100 year horizon. For example, Sulphur Hexafluoride has a GWP value of 23,500!
Another important consideration is the atmospheric lifetime of greenhouses gases as they can break down in the atmosphere, deposited onto the surface with rain, or put back into another phase, like a solid or liquid. For example, when a tree grows, the process of photosynthesis fixes atmospheric carbon into a solid state in the form of glucose, providing energy for plants and animals. Similar to GWP, it is often the case that greenhouse gases from industrial sources have a much longer atmospheric lifetime. Sulphur Hexafluoride tops the charts again, as it has an atmospheric lifetime of 3200 years.
Above: GWP and Atmospheric lifetime table of common greenhouse gases
For Erden, understanding these changes is extremely important because it forms the base of Climate Models and some of the Earth System Models. The difference between the two is that Earth System Models usually includes an ocean component in climate prediction, meaning changes in ocean currents and its effects on the climate is also included. With these models we can also apply different radiative forcing, such as different concentrations of greenhouse gases to see how the average surface temperature and future climate might change. Here is a very simple interactive online climate model from the University Corporation of Atmospheric Research. Click here to give it a go and see how the temperature can change with different rates of greenhouse gas emissions and concentrations!
Remember how Erden has studied over 10-15 years of meteorological and climate data in preparation for his ocean crossings? We here are slowly doing the same, first understanding the basics on everything that is related to the open ocean. Because as Erden writes:
“ It (the ocean) is just there as a formidable foe, raising and dashing one’s hopes on a regular basis. It is an honest teacher, quickly exposing my weaknesses and rewarding my strengths. If I prepared well, we get along just fine, else it knit picks every gap in my defences.”
It is obvious now that Ocean Rowing is not just about having the strength and endurance and more like a game of chess, requiring you to anticipate the counter moves and adjusting to surprise attacks. Only the game piece is yourself and your rowboat, and your opponent is the wild elements of the Ocean.
Westbound Rower Education Week 15: Ocean Acidification
Now that Erden has left Hawaii (on October 7th, 2021) and is making his way towards the Malaysian Peninsula, the full-fledged Westbound Wednesday is back on the menu. Before the short break where Erden went on making repairs to his rowboat and connecting with schools all over the world, we discussed the implications of a changing climate on the ocean environment. Today we will continue on this topic and take a look into Ocean Acidification.
Above: Erden’s Live Tracker (October 15, 2020)
Ocean acidification describes the process of lowering the seawater pH (measurement of acidity) and carbonate saturation that result from increasing atmospheric carbon dioxide concentrations. The Ocean is one of the largest storage sink of carbon on the planet, and it has been estimated that the Ocean absorbs 30% of carbon released into the atmosphere. When more carbon dioxide is released, more will be dissolved into the ocean. This process is naturally occurring and the balance between atmospheric and oceanic carbon has and will continue to influence our climate in the future.
pH is the measurement of acidity. Low pH value solutions are acidic (0.0 - 7.0 pH), and solutions with high pH values (7.0 - 14.0) are basic or alkaline. Pre-industrial period ocean surface pH was approximately 8.2, and thus considered alkaline. Since then, with our increasing consumption of fossil fuels, deforestation and other carbon dioxide releasing activities, the ocean pH has dropped by 0.1. The pH level of the Ocean today is generally agreed to be around 8.1, and still alkaline. A change of 0.1pH does not seem like much, however the pH scale is logarithmic, where a decrease of 1pH represents a 10x increase in acidity! This means on average, acidity of the ocean today is estimated to be 25% -30% more acidic than it was just 200 years ago. Via coupling of different climate and ocean models, projects suggest the pH will continue to decrease in the future and the pH level could be around 7.8 around the year 2100. So while we say ocean acidification is occurring, it is not like the water in the ocean is becoming an ocean of acid. However it is changing enough to cause negative impacts on ocean life.
Above: pH Scale
For us humans, this change is extremely unlikely to affect us, as the sea water is still alkaline. For other life however, the change pH can cause much damage to species life histories and ecosystems as a whole. But how does increased dissolved carbon dioxide translate to decreasing ocean pH?
In the atmosphere, carbon dioxide is a relatively stable and inert gas, and does not chemically react to other gases much or at all. This is because of the structure of carbon dioxide, having strong double bonds between each of the two oxygen atoms and the carbon atom (making CO2). When carbon dioxide is dissolved into the ocean, the sea water interacts with the carbon dioxide and lower the pH of the water through several chemical processes.
Above: CO2 atomic structure
When carbon dioxide is dissolved in water, aqueous carbon dioxide is produced (CO2(aq) ). in this form, the aqueous carbon dioxide can interact with water (H2O) to form carbonic acid (H2CO3). Thankfully carbonic acid is a weak acid, and we occasionally intake traces of it when we have carbonated drinks.
Carbonic Acid does not stay in the ocean water for long as it easily splits apart into bicarbonate ions (HCO3-). Bicarbonate ions in turn can further split into carbonate ions (CO32-). Both of these reactions produce protons (H+) that contribute to lowering the pH of the solution, causing the sea water to become more acidic. It should be noted that the reactions below can also go to the left, where an unbalanced excess of protons in the water can react with carbonate ions to produce bicarbonate ions.
Above: Chemical reactions involved in Ocean Acidification
Marine life underwater is highly sensitive to this change and some species are more affected than others. The general consensus among scientists remains that the potential impacts are generally negative, with magnitude of effects highly variable across and dependent on the local environmental stressors and ecophysiology of the species. Because of the added carbonic acid, bicarbonate and carbonate ions in the water due to more dissolved carbon dioxide, many studies investigating the effects of Ocean Acidification target ocean calcifier species. In general, the calcifier species umbrella term can include molluscs, echinoderms, cnidarians, crustaceans and corals. Next week we will look investigate the effects of Ocean Acidification in crustaceans and corals as a case study.
In Erden’s situation, is a changing Ocean pH critical to his plan to row across the Pacific? Likely not. But being such an important indicator of water quality, Erden will almost certainly be aware of it. He may want to make sure the water coming coming out of his desalination unit is at a neutral pH (or close to pH level 7). His chart plotter is also likely to capture the ambient pH of the rowboat’s surrounding, but unlikely to affect Erden’s crossing.
Above: Erden Rowing out of Hawaii
Having set of last Thursday October 7th, Erden has already made some progress in week one, using the north equatorial current to Mariana’s, which he hopes to reach some time in January. Erden expects this leg to be even tougher than the first 80 days to Hawaii, when he makes it across the Pacific he will also become the first human powered vessel that venture west of Hawaii with the intention of landing in Asia. Navigation of this relatively untouched part of the ocean will be spearheaded by Erden’s friends and Team. Jason Christensen from “Racingthewind” and researchers Dr. Nicolai Maximenko and Jan Hafner from the University of Hawaii, who will be likely guest speakers in future live sessions with us and Exploring by the Seat of Your Pants!
Week 16: Ocean Acidification Effects on Corals and Crustaceans
Ocean Acidification (OA) which reduces the PH level of the ocean through the chemical reactions that occur when carbon dioxide is dissolved into seawater from the atmosphere. When carbon dioxide is dissolved in water, it is then able to alter the delicate balance of bicarbonate and carbonate ions, which affect the availability or saturation of carbonate ions, which could be fixed into calcium carbonate, a critical mineral in the structure of many marine organisms. One of the observed effects of OA towards calcium carbonate fixation is that large parts of the ocean are becoming undersaturated with carbonate ions, meaning there is not enough of the necessary chemicals to maintain the shells and other hard structures used for survival.
Species that make use of calcium carbonate and fixes them from the seawater are called calcifiers, often building shell, skeleton and exoskeleton structures. This has been known throughout history from the vast fossil record in limestones. Within the califiers, there are two groups of species that have a significant impact on the marine and the human ecosystem, corals, and crustaceans. While Erden is unlikely to find corals out in the open ocean as he is now, he is always on the lookout for barnacles. Barnacles are a type of crustaceans that require a substrate or surface to attach to. A natural substrate could be anything from rocks at the shore, to even the skin of large whales! They can also be found attached to pieces of plastic in the ocean, travelling along with it. They can also thrive on the hull of boats, being a nuisance for ocean going vessels by producing drag, making it more difficult to row in Erden’s case. Making sure the rowboat was barnacle-free before the launch from Hawaii was one of the tasks Erden had to do before he set off again, improving the hydrodynamic efficiency of his rowboat for the remainder of the expedition.
Above: Barnacles attached to whales and plastic
The most well documented impact of OA is in corals, because the visual impact of coral bleaching is difficult or near impossible to argue against. Their ability to bounce back from disturbances are also affected by OA, as seen in the lower spawning and reproductive rates of corals under stress from OA and physical disturbances such as storms. Coral reefs are a lucrative resource for coastal tourism, with major coral tourism hotspots like the Great Barrier Reef receiving over 5 million visitors each year before 2019 according to WWF. On an ecological level, coral reefs are even more important than its economic implications since it is home to a quarter of the documented species in the ocean. What’s even more amazing is that the total reef area on Earth is less than 1% of the ocean floor.
So are shallow water corals really being “bleached” in the literal sense? Not exactly, because the story or corals losing its vibrant colours is related to the coral losing the photosynthetic algae, zooxanthellae. As the density of zooxanthellae decreases, the coral eventually loses its colour eventually exposing the white calcium carbonate skeleton. Without the zooxanthellae, corals can still survive for a short period however extremely vulnerable and gradually lose much of their natural ecosystem services.
The relationship between corals and zooxanthellae is mutualistic, a symbiotic relationship where both species (the coral and the zooxanthellae) benefit from their interactions with each other. Most reef-building corals contain this type of photosynthetic algae. Corals provide zooxanthellae with a protected environment and compounds the algae needs for photosynthesis. Coral tissue is clear for this reason, so that it maximises the light that can get through to the photosynthetic algae. In return, zooxanthellae supply the host coral with glucose, and other products of photosynthesis that could be used by the coral to grow and produce its calcium carbonate skeleton. As much as 90% of the material produced by the zooxanthellae is transferred to the coral tissue and is a driving force in coral productivity and method to recycle the limited resources in low nutrient, clear shallow waters typical to coral reefs.
Above: Process of Coral “bleaching”
Temperature is another key driver of coral bleaching, because warmer waters increase the rate of photosynthesis, so in a way, it is good for the algae. However when this process runs too fast, the cells of the zooxanthellae start to release compounds toxic to corals because of the lack of repair. As an immune response the coral actually ejects the algae out of their tissues, exposing the white calcium carbonate skeleton of the coral. When this occurs at the scale of an entire reef, all of the expelled and rotting algae can severely degrade the water quality, and everything else living on the reef.
Crustaceans are important in marine ecosystems because they’re extremely diverse, coming in a large variety of shapes and sizes, and having been found to be extremely resilient as they can be found in all parts of the ocean. Crustaceans are an important source of food for a lot of marine species, for example krill (average 5cm) is the main source of food for the blue whale, the largest animal to ever roam the ocean and the planet. Humans also cultivate crustaceans for consumption, common ones you may have eaten in the past include prawns, crabs, lobsters.
Crustaceans have a rigid exoskeleton made of a layered cuticle, covering its soft body parts for protection from competitors and predators. The exoskeleton contains a large amount of calcium carbonate, which makes them more rigid. As a result, crustaceans cannot grow without molting or shedding its shell. A key impact of ocean acidification on crustaceans is therefore its ability to maintain its shell as it grows in waters that are increasingly undersaturated with carbonate ions necessary for producing calcium carbonate. Some studies have observed a trend of thinning in the cuticle because of OA, which have also been observed in many shellfish species. The thinner cuticle can cause the shell to become brittle and subsequently more susceptible to predation. Some aquaculture farmers have also chosen to alter the carbonate chemistry to help the growth of lobsters and crabs.
An interesting ability crustaceans have is their acid-base regulation ability, which helps buffer changes to their internal pH, and allows for the calcium carbonate calcification process to be less affected by changes in water chemistry. This has been suggested as one of the reasons why ocean acidification impacts no net calcification appears neutral across many crustacean species, some even exhibit increases in net calcification in lower pH waters. This all sounds a little counterintuitive, but if maintaining the calcium carbonate density in its shell is still a more competitive way to survive, the metabolic increases in calcification may come at the expense of other physiological processes. Indeed, some negative effects such as reduced growth and increased mortality have been observed in crabs, barnacles, and shrimps.
It is difficult to say what would happen or how much effect ocean acidification may have on the barnacles on Erden’s boat. In the past 10 days, the winds and currents are on Erden’s side and has covered just about 500 miles already. During these 10 days, one of his highlights was encountering the USCG Cutter MUNRO, a US coast guard on patrol 278 miles west of Waikiki, which stopped to give Erden a check on October 13. It is awesome to see that even out in the ocean there are always those looking out for a lone rower!
Above: Erden’s Rowboat next to USCG Cutter MUNRO
Westbound Rower Education Week 21: The Global Shark trade
Above: An Oceanic Whitetip Shark next to Erden’s Rowboat
Sharks are extremely important species in ocean ecosystems. They are what we call apex predators, and predator species are at the top of the food web and have little to no natural predators. At the top of the food web, shark populations can influence the population of other species in the food web through predator-prey interactions, which serves to regulate and maintain ecosystem balance. Without sharks and other predators maintaining the balance, we may see growth and decline of different species which may lead to ecosystem collapse. We humans disrupt the ecosystem balance by overexploitation and overfishing in the ocean. Larger fish, and species at higher trophic levels are more sought after by the market. By having greater value, large fish and sharks often become targets for commercial fisheries. Today, population of some shark and ray species have decreased as much as 95% while 36% of more than 1200 known shark and ray species are threatened with extinction.While it is good practice to eat less seafood, we have to remember that over 1 billion people rely on marine resources for protein, such as subsistence fisherman and small-scale coastal villages.
Sharks have been living in the ocean for the past 400 million years - that’s before the dinosaurs! Having been here for such a long time, their life histories have largely been unchanged and have been extremely successful in evolutionary terms. Sharks are known as “K-selected” species, which means their strategy features slow growth, later maturation, longer gestation periods, produces few offspring and often have long life expectancies. Humans, whales and many mammals are also considered “K-selected” species. The opposite are the “R-selected” species, that mature faster, produce many offspring, and die quickly.
Above: The K-selected and R-selected life histories
Sharks are particularly vulnerable to overfishing because of their biology because they cannot reproduce fast enough to maintain their populations. In a recent study from Nature, it is revealed that the global abundance of sharks has declined more than 70% since 1970, largely because of increased fishing pressure and demand for shark products. The authors of the study called this decline an “unprecedented increase in the risk of extinction” for these ocean predators.
It is unfortunate that sharks also have a bad reputation in the media, coming off as terrifying, dangerous and will actively attack humans. This is far from the truth, as shark attacks often originate from either confusion or curiosity which then may lead to an accidental attack. These incidents are uncommon, with fatalities even rarer. In the past decade there have been on average 77 shark incidents each year, with about 10% fatalities. By comparison Box Jellyfish sting and kill between 50-100 people each year, they are also unique among the jellyfish because they actively swim and hunt prey!
Above: Different types of Shark Products
The shark trade is the global commercial trading of shark products such as shark meat, shark skin, oils, teeth, cartilage, and the most valuable of them all, shark fin. Hong Kong and China are major trade and consumption centres of seafood in East Asia, especially the “luxury seafood” items like shark fin, abalone, and groupers among others. These luxury items are also encouraged by the trade’s relatively high export value, and the result is ever increasing fishing pressure for these products, and subsequent decline in wild stocks.
Among the luxury seafood products, shark fin has attracted the most attention and conservation concern. Historically, shark fins are regarded as a prized cultural item, which ultimately led to it becoming a part of formal banquets dating back to the Ming Dynasty (1368-1644 AD). Being such a prized item, demand for shark fin remained relatively low until the 1970s with the growth of the Hong Kong stock market. Shark fin soup is by far the most popular product consumed in Hong Kong which uses a shark product. In Chinese tradition, the consumption of shark fin was associated with a variety of benefits from increased virility to longer life, however scientific studies have shown no such health benefits in consuming shark fin which is purely cartilage. A 2012 study of fins from seven shark species found high concentrations of the neurotoxin BMAA and shows no health benefits. BMAA is associated with several degenerative brain disorders from Alzheimer’s, Parkinson’s and ALS. BMAA concentrations were also found to be greater in fins than other parts of sharks.
Above: The Dried Seafood Markets and Shark Fins in Hong Kong
Hong Kong is an important trading hub for shark fin, handling up to 50% of the global shark fin trade. Other key hubs for shark fin trade include Singapore, Malaysia, Japan, China, and Indonesia. Surprisingly, up to 22% of the shark fin traded in Hong Kong are imported from Europe with Spain being a large contributor. On the other hand, shark meat and oils tend to be the main products traded in Europe and the Americas with Brazil, Italy being the largest importers.
Trade dynamics form the basis of understanding the global demand and supply of shark fin. The shark fin trade is heavily dependent on the availability of transportation moving shark products from source to consumer countries. Because of this there is still plenty of uncaptured data related to the species, volume traded, source country and destination. This type of information can be collected via port customs. The data can aid a series of reforms in relevant legislation that may have the capacity to regulate the global shark trade, to minimise the negative impacts of the shark trade and provide future direction of shark conservation.
Above: Shark Finning
The act of shark finning is extremely damaging to the natural ecosystems, as the practice involves intentional capture and de-finning of the shark, then discarding the live shark body back into the ocean. Without its fins, the shark is unable to swim and sinks to the bottom of the ocean where it suffocates or is eaten by other predators. This is a profit-driven practice as shark fins is by far the most profitable part of a shark, and by removing the bulky body of the shark it can allow each vessel to increase the number of sharks harvested. Although shark finning is banned in many countries, the lack of enforcement and regulation continue to be a concern. To overcome this problem, some countries require the whole shark to be brought back to port before removing the fins, and to ensure the rest of the shark is utilised in the shark trade.
The good news is that in Hong Kong there has been a shift in attitudes towards consumption of shark products, an encouraging sign as the general public are starting to see the environmental concerns. Driven by concern from the general public, a 2018 report showed the volume of shark fin imported into Hong Kong has declined by over 50% between 2007 and 2017, from 10,210 tonnes to 4979 tonnes. Growth of public pressure and brand targeting has also seen positive results as hotel and resort groups, and banquet venues removed shark fin soup and other shark products from their menus. Airlines such as Cathay Pacific announced they would stop shipping shark fin in 2016, which contributes to the continued decline in shark fin imports. You can hear more about the shark trade in Hong Kong in the podcast Trash Talk where the founder of Hong Kong Shark Foundation (Andrea Richey) and founder of Ocean Recovery Alliance (Doug Woodring) discuss Hong Kong as a free trade port, the environmental footprint of what is consumed and traded through Hong Kong
In the shark fin trade, not all shark fins are equal. Artisanal fishers may utilise whatever species of shark they catch, but markets supported by international trade have distinct preferences. For example, the critically endangered scalloped hammerhead shark
Above: CITES listing on Shark Fin Trade in Hong Kong
The United Nations Convention on the Trade of Endangered Species of Flora and Fauna (CITES) is a multilateral treaty to protect endangered plants and animals. Several shark species are also listed within CITES. As of 2017, 13 species of shark are listed under CITES but many suggest it is not enough, as the international Union for Conservation of Nature (IUCN) has designated Red List status for nearly 100 shark species. Within this list, IUCN also finds that over 25% of these are threatened with extinction. Shark fin being a dried shark product also adds additional challenges to species identification of fins, where DNA analysis is the only credible method of identifying the species, and the life history of the shark. Many shark fins are traded with the skin and other morphological features removed and mixed in stockpiles, adding further complications in cataloguing.
So where do all these sharks come from? A recent 2020 study from Biology Letters combined DNA barcoding and species distribution modelling to identify species and their geographic origins. Their findings showed that shark fishing efforts are concentrated within Exclusive Economic Zones (EEZs) in coastal Australia, Indonesia, United States, Brazil, Mexico, and Japan. EEZs are areas of the ocean where a country has the rights to explore and use marine resources within the area. Generally, EEZs extend no more than 200 nautical miles (370km) from the coastline. Since the largest proportion of shark products originate within EEZs, nations need to adopt enforceable conservation measures within their jurisdictions.
Above: Model showing probability of shark product origin at four different trading hubs
You can also make a difference by simply refusing shark products! By saying No to shark products, you are effectively showing there is less demand for shark products. You can also choose to not visit restaurants that use shark products, calling for companies to stop this practice. Education on sharks can make you more knowledgeable about these creatures that have roamed the ocean for over 400 million years, and the little threat they have to humans compared to our impacts on shark populations.
Westbound Rower Education Week 23: Fisheries and Aquaculture
Overfishing is a huge issue for the ocean’s health, as each year, more than 80 million metric tonnes (MMT) of wild seafood is extracted from the ocean, this volume of ocean-based protein is comparable to the global production of beef (64 MMT), Poultry (98 MMT) and pork (115 MMT). The aforementioned 80 MMT of seafood only describes the wild catch, and the reported catch. There is a large volume of illegal open-sea fishing which goes completely unreported, and this is highly destructive to the ocean ecosystem. When combined with the totals from aquaculture total ocean-based protein harvested from both sources is well beyond the 160MMT. The global production of seafood has quadrupled over the past 50 years. In the same period, the global population has more than doubled, and the intake of sea-based proteins per capita has also doubled. This increasing trend in consumption has increased pressure on fish stocks across the globe with many already considered overexploited.
As a result of this pressure for consumption, overfishing and the overuse of ocean resources are one of the top environmental concerns because it can cause collapses in different ocean ecosystems. In commercial fisheries, it is common for fisherman to catch certain target species, which are driven by consumer command. As more of the targeted species population are removed from the ocean it can cause the ecosystem to become unbalanced. Furthermore, targeted species are generally larger in size, higher in trophic level, and often key predators in their ecosystem. An example are sharks and tuna, both of which keeps the populations of other species in check through predator and prey interactions. Without these predators, populations in the lower trophic level can cause cascading effects that will affect ocean ecosystems.
In commercial fishing, the selection of fishing method plays a major role in determining the cost, efficiency, and the amount of bycatch (fish, animals or birds which are caught by accident, and not intended as part of the “harvesting” of the intended species). Another key objective is to gather and catch as much as possible before returning to port to sell the catch. This is one of the reasons targeted species are a problem, as higher-valued fish will always be prioritised, and the lower valued ones are often thrown overboard. Shark finning is an extreme example as fishmen discard the body of the shark in favour of only keeping the high value fins, because the body of the shark is less valuable, heavy, and too difficult and bulky to store.
Small scale fisheries on the other hand are highly dynamic and usually well integrated into local marketing arrangements, so the distance from catch to consumer is short. The fishing range is short, often only along the coastline, and is reflected by their techniques and fishing gear used making it a labour-intensive activity. These boats usually do not have refrigeration or storage capacities either, so the volumes taken are smaller, and time-to-market is faster. The productivity of small scale fisheries should not be understated, contributing to sustainable livelihoods, food security and nutrition for many coastal and island communities as well as playing a role in the global fish trade.
Most fish today are caught using nets, but there are several types of nets. Purse Seine fishing is the most common as it can be used by boats of all sizes. This works by first dropping a net near a school of fish, then using the boat to around the fish while taking one end of the net. When the two ends are linked back together, fish can be pulled onto the boat. Buoys and other large floating objects attract fish and will often be deployed to attract fish rather than actively searching for schools in the ocean. These devices can attract all kinds of fish, sometimes even their predators, causing accidental bycatch.
These are called Fishing Aggregation Devices (FADs), and the Japanese fishing industry estimates that there are over 40,000 of these floating in the Pacific. They have transponders/GPS units on them, so they can be found for fishing, but, when the transponders run out of batteries, the FADs are usually lost to the ocean. These FADs have often large net structures hanging from them, 5m to 10m in depth (15 to 35ft), acting as vertical reefs which small animals make their homes on. Molluscs and fish eggs might be laid on these structures, attracting small fish as it is an easy food source. The small fish will attract the bigger fish, which is what fisherman want.
Lost FADs area what are a major source of ghost nets, which are old, lost fishing nets, which continue to float in the ocean and cause destruction to wildlife that accidently gets caught in them. They also cause damage to the propellers of huge ocean-going tankers or other boats when they get hit. There is currently a global movement to ban and reduce the use of FADs, but few people know of them, and it is extremely hard to monitor and enforce in the great expanse of the high seas.
Erden’s rowboat also attracts fish that follows him across the ocean, and over time attracting larger fish like the suspected Marlin and shark sightings, turtles, and birds that feed on the fish around the rowboat.
Above: A suspected marlin underneath Erden’s rowboat
Trawling is when the net is being pulled through the water behind a boat and can be done in the water column or at the bottom. Bottom trawling is when a weighted net is dragged across the sea floor to scoop up fish, crustaceans, and other benthic creatures. This practice is particularly damaging to the ocean ecosystem because it will scoop anything up, including deep sea corals, and sponge-dominated communities that take a long time to regenerate. In fact, it is much like bulldozing the bottom of the ocean floor, when the nets drag across the bottom. Imagine if we allowed bulldozing in our parks to catch butterflies, bees or mice! This is not much different.
Even though there have been countless studies on the negative environmental effects, the practice is not banned in most countries. The United States, Canada, Australia, Brazil, China and Malaysia established no-trawl zones to avoid damage towards sensitive ecosystems. The European Union however, has been resistant to put legislation against this fishing practice. Currently only Indonesia, Palay, Belize and Hong Kong have completely banned this practice. While it is banned, the legislation may have come too late in Hong Kong, as many fishermen were happy to sell their trawling boats, because bottom trawling yielded only the most dismissal of catches, with average length of fish being around 4-inches. Since the trawling ban at the end of 2012, the water quality in Hong Kong has also seen significant increase because there are less disturbances to the seabed, and proof that the ocean can recover if given the chance!
Above: Bottom trawling
Gillnets do not need to be pulled behind a boat and are deployed like a wall for the fish to unknowingly swim into and get stuck in the thin, translucent filament, often catching their gills, and thus the name. Because they don’t require a boat, gill nets are often used in small-scale fisheries. Larger commercial versions do exist with nets spanning multiple kilometres in length. This method has the most bycatch where is not uncommon to find species of turtle, sharks, dolphins and even whales getting caught in these nets. Drifting gillnets can be set to drift with the current, like stationary gillnets they also have issues with bycatch, and have the chance to be lost and become plastic pollution in the ocean. They also easily get tangled and caught in coral reefs, on rocks, and in mangrove forests.
Long Line fishing is another destructive method where bycatch can be significant. Some fishing boats use fishing lines of 60km in length (over 36 miles long), with tens of thousands of hooks. Used to catch big fish, like tuna and marlin, they also catch sharks, turtles, birds and other large species. They can also easily tangle up a whale.
Aquaculture is the practice of culturing fish, crustaceans, shellfish, aquatic plants, and others from spawn to maturity, with the intention of selling or consuming the product. It can be applied to both freshwater and seawater species with unique methods for both. Aquaculture has been around for a long time, with evidence from hieroglyphics and other ancient manuscripts dating back 4000 years. The first book (The Classic of Fish Culture) written about aquaculture dates back to 475BC in China. But it is only in the past 60 years when the aquaculture has begun growing at a pace to support the growing demand of seafood products. Most of the growth in aquaculture production has come from East Asia and the Pacific. China produces the most in the region, with more than 65MMT recorded in 2018 China’s aquaculture output accounts for around two-thirds of the world’s aquaculture production. In fact, over 50% of the world’s seafood protein is now produced via some form of aquaculture. That doesn’t reduce the stress caused from overfishing, however, as its still easier for many countries to support boats to go find fish, rather than to take up coastal or inland space, and risk growing seafood, when there are also issues with disease and pollution which are not the case with free-range species.
Above: growth of aquaculture by region (1950-2018)
Mariculture is the type of aquaculture that is practiced in marine environments and underwater habitats and would therefore involve the use of sea water. Because of this it is often found in a section of the coastal ocean, in saltwater ponds or on land in salt water tanks. Fish farming remains the most common type, by selectively breeding certain species of fish, the production cost of fish as a protein source remains low. Fish farming is also not care-intensive, and the fish culture only requires food, and suitable water conditions (water chemistry and temperature) for growth. Other organisms bred using mariculture methods include molluscs, shellfish and even seaweed. In recent years, the sea plants and other animal species has found many uses in industries outside of the food industry, for example pearls from oysters and collagen from seaweed are often made into jewellery and other cosmetics.
Other recent developments in aquaculture include the advanced system of aquaculture where different trophic levels are mixed to provide nutritional needs for each trophic level. Called the Integrated Multi-Trophic Aquaculture, this method attempts to emulate ecological systems that exist naturally. As resources are transferred between trophic levels, the practice can reduce waste while producing greater yields. In some cases, a mixed farming method can also be applied, adding small scale agriculture adjacent to these types of fishponds. Using advanced irrigation systems, water can be cycled through the farm and fishponds, allowing for nutrients to be shared between the two further enhancing productivity from the aquaculture and agriculture system.
While it seems like aquaculture can solve many of the problems we face with declining wild fish stocks, the exponential growth of farmed fish (mainly in China)has also caused much environmental damage specially to water quality near inland fish farms. Excess nutrients, uneaten fishmeal, and faecal matter in larger numbers of farmed fish can cause marine and freshwater eutrophication altering oxygen consumption dynamics within the ecosystem. In ponds, hypoxic conditions from eutrophication are associated with mass fish death and death of other animals. Parasites can also grow in densely populated fishponds, which could spread to other areas. Invasive species are another concern as escaped fish may be more competitive than species native to the region negatively affecting natural food sources and populations of local species. It is more than likely that with continued development in the field and application of sustainable aquaculture methods and monitoring, many of these negative effects can be mitigated. However, given the industry is driven by consumer demand it is often about our individual choices, and our careful selection of seafood from sustainable sources, whether from wild-catch or aquaculture, will go a long way in incentivising the necessary change towards ensuring sustainable seafood systems.
Westbound Rower Education Week 25: Approaches to Sustainability
Erden is now more than two thirds of the way across the Pacific, and we will begin to change gears to discuss solutions and how we can go about making the changes needed to address the many environmental issues mentioned since the start of Erden’s expedition in June 2021. In the pursuit towards sustainability, and while perhaps cliche at times, we are to conceptualise them as “Bottom up” and “Top Down” approaches.
Sustainable use of the planet’s finite resources is the most complex problem in human history. Its goal requires a shift in behaviour and practices so that the human species can live on the planet indefinitely. This requires a mutualistic relationship between human systems (society), and natural systems. Ecology and Economics are both derived from the Greek word oikos, meaning household. To protect the ultimate household, Earth, the economy and other practices should all be structured in a way where the planet’s ecological life support system would not be damaged as a result.
“Top down” sustainability encompasses highest system-level changes that are driven by policy, legislation, strategy, and operation directives. These are often directed from the top levels of government to achieve their sustainability targets. Strategies that are designed for specific components, local communities and have a regional impact to the strategy are referred to as “Bottom-up”. From this very generalised definition, there are many existing approaches to sustainability that fit somewhere in between.
Another way to conceptualise the two, is the relationship between behaviour and policy. With bottom up influencing policy through behaviour, and top-down approaches attempting the opposite, they change behaviour through policy. Individual behavioural changes can have great potential if adopted by many, just like how our choices as consumers can affect the overall outcome of our food systems as discussed in previous weeks. In plastics, increased knowledge and shift in opinions have led to policy changes in some countries to ban disposal plastics, improve recycling rates and increase the use of recycled plastic rather than using virgin plastics. On the other hand, the top-down approach of plastic bag levies have also shown to be effective in changing behaviour by charging consumers a tax for using plastics.
Above: Bottom up and Top down approaches for climate adaptation policies
In recent years, there has also been an increasing interest for corporates to improve their company and operations towards a more sustainable future. Their methods and approaches to sustainability could also be conceptualised as “Top down” and “Bottom up”. However, unlike the government level changes, the scope of corporate sustainability is much smaller than the former, often selecting a specific problem to target its effort, or to make its business model more sustainable.
So why are “Top Down” approaches important? It is because changes at the highest level are essential to making transformation changes in a government or company. These are often the long-term and big-picture changes strategies that will determine the sustainability targets we set out to achieve. With this vision, plans and strategies can then be put in place from the highest system level, thus being top down.
“Bottom up” approaches are different because there is a much higher level of engagement with people, and groups, and of course directly with the problem it is trying to solve as well. Instead of making system level changes, “bottom up” strategies make local targets that are much smaller in scale. Individuals are extremely important because they require individuals or groups who help make these targets happen. In a way, there are many more hands-on roles in “bottom-up” strategies, with a good team, goal, and solution, there are many opportunities for quick wins. There is also a strong relationship with empowering the local communities and supporting local economies. At the same time, these approaches could identify different barriers to change, while building a community that is ready to embrace major changes that will come into effect. By identifying barriers and achieving small scale targets, the momentum these projects or programs create, complement and can improve the target set in place by “Top down” approaches.
One of the limitations of the top-down sustainability is related to the time-frames involved with these plans. The lead-up time for achieving these targets can be lengthy, with many political obstacles in the way. The number of stakeholders involved is large, and often comes with a series of complex competing interests, which makes coordination and achieving consensus a difficult challenge for achieving these goals. An example of this are the Nationally Determined Contributions many countries have made as part of the Paris Agreement, for 2030 and 2050, where in many countries trends of increasing greenhouse gases (CO2-equivalent) continues to increase at an alarming rate even though many emission reduction targets have been made.
Above: Comparison of NDCs to different RCP scenarios (Paris Agreement to keep within 1.5C)
Barriers to bottom-up approaches are equally complex, and are closely linked to individual, cultural and religious belief systems, socio-economic status, disparities in education, scientific and environmental literacy, and even compassion and equity for future generations. All of the above can drive an individual to act or react differently to rising environmental concerns, and are one of the reasons why bottom-up approaches often require the “quick win” as mentioned before. These can impact the relationship with growth and development in the local and regional economy. With added economic value to these approaches, better management strategies can be adopted to improve both ecological systems and human livelihoods.
The bottom line is that sustainability requires engagement at all levels, from the highest system level, to the level of individuals and everything in between. The complexity arises from the fact targets and solutions at each level require different techniques, time frame and scope. There are also no right or wrong answers as to which approach is better, because the outcomes of both approaches complement each other. By embracing both approaches to sustainability, we can maximise the opportunities to find balance between the structures of the ecological and human systems.
Week 26: Top Down and Bottom Up Approaches for the Plastic Crisis
Last week we discussed the differences between Bottom Up and Top Down approaches to sustainability, or the directions which we could use to solve some of the environmental problems we face. Another take-away is how the two approaches have a mutualistic synergy where success relies on efforts of both approaches because of the relationship between individual behaviour and policy. Presently, plastics can be considered a “hot-topic” environmental concern, much like climate change, and require effort and of both types approaches. In this post, we will look at some examples of both.
Let's first look at the Top Down approaches for plastics, which are mainly implemented by governments through policies. A recent study reviewing recent trends in government action to combat plastic pollution include policies such as, bans, levies, taxes, agreements between public and private partners. Other options include designs related to circular approaches which help guide the improved design of production, consumption and disposal of plastic waste.
Policies relating to consumption typically result in responses from government which are related to the implementation of product/packaging bans, replacements and improved waste collection. An interesting finding about the countries which implemented these policies are that they are typically adopted where governments are “unable to improve waste collection services, and where they have little control over the design of the product in their market” (Godfrey, 2019). Many countries first implement policies related to single use plastics; especially plastic bags, bottles, and microbeads in cosmetic products. With many countries finding the total volume of waste remained unchanged or continued to grow, there are growing trends in policies that act towards more complex items like food packaging, tires and textiles.
At present, many countries already have charges for single use plastic bags, and reviews generally show that these levies seem to be effective, at least in the short term. Hong Kong implemented its Plastic Shopping Bag Charging Scheme in 2015, where a $0.5 cent HKD ($0.06 USD) fee is charged for each plastic bag. This scheme worked initially, in the first two years, proving to be effective in reducing the use of plastic bags. More recently however, a survey found the levy to be losing its effect, with nearly half of the respondents indicating they would still accept plastic bags despite the levy. The same survey suggested that only a quarter of respondents would accept plastic bags if the charge were to be increased by 100% to HKD $1.0 (USD $0.13). A levy of HKD $2.0 (USD $0.26), however, would deter most from plastic bags, with only 8.6% still accepting. One of the reasons why these schemes lose effectiveness over time is because the current 50-cent levy has already been absorbed by the public, and is no longer sufficient discouragement from using plastic bags. Another critique is that not all plastic bags are included within this scheme. For example bags used for food hygiene (bags that carry foods without packaging or airtight packaging), bags used for packaging, and bags provided by retailers as part of services tendered do not need to be charged the 50 cents. Thus leaving an extremely large grey area in which single use plastic bags can still be distributed freely.
This plastic shopping bag charging scheme in Hong Kong is still in effect, though it is no longer as effective as it once was because the policies are brought on only from a top-down approach, and without the right engagement with the public. The policy was therefore not effective in changing individual behaviour. This was demonstrated by the fact many continue to use single plastic bags citing hygiene, and indicating that plastic bags were necessary for items they bought as the top reasons for continuing to use single use plastics. There are also no incentives (or dis-incentives) for retailers to stop using plastic bags, as many shops continue to freely provide unnecessary plastic bags like these ones below, freely handed out by McDonald’s for carrying their drinks in Hong Kong, and other parts of Asia.
In contrast, suitable bottom-up approaches are much more effective in changing individual behaviour, which then have the potential to address the barriers to change and benefit future top-down strategies to plastic. One bottom-up project that Ocean Recovery Alliance has created is the Water Falling Festival and Water Rising Festival at the Tonle Sap Lake in Cambodia.
Above: Tonle Sap Lake basin and flood plain
The Tonle Sap Lake is located north of Phnom Penh, the capital city of Cambodia. It is characterised by large fluctuation in surface area which changes every wet and dry season. At the end of the wet season, the Tonle Sap Lake is the largest freshwater lake in Southeast Asia. At the end of the dry season, the Tonle Sap Lake, which is still a large lake, shrinks to a third of its size, from around 10,000 square kilometres (max) to 3,000 square kilometres. It provides water for half of Cambodia’s crops, yields half of the protein (fish) for the entire country’s population, and a major transportation link in Cambodia, and thus extremely important to the wellbeing for those living in and around the lake.With inland fisheries and tourism being the main economic driver for local communities, the health of the link is directly linked to their livelihoods, and without an effective waste management system and the know-how, plastic and other waste end up in the waterways and the lake. As a result, plastic in the water and along the shoreline were a common sight within the UNESCO Biosphere Reserve.
The Water Rising and Water Falling festivals were created by Ocean Recovery Alliance and NGO2 Foundation, to bring new awareness and water appreciation to villages along the Tonle Sap Lake. The two events are timed with the dry and wet season, where The Water Falling Festival happens in late November, marking time when water recedes from villages, often pulling plastic with it and into the Tonle Sap lake. Being a bottom-up approach, the goal was to engage the community and incentivise behavioural changes for the better of the environment, and introduce new recycling or waste management programs so plastic does not end up in the environment. So far these events have engaged more than 12,500 members of the community, from youths, fisherman, monks, to the local government; which began a similar Siem Reap River Festival that has similar goals. In 2019, over 40 tons of plastic were removed from the rivers flowing into Tonle Sap Lake and the lake itself from these programs.
Above: Before and After the Water Falling Festival cleanup event
Also introduced through festival was the “Harvest Plastic” program which came with specially designed “rice bags” for the program. These bags are designed for collecting plastic from the household and environment in remote villages of the province of Siem Riep. But how do you encourage individuals to follow-through with action? A method is through tangible rewards. In the “Harvest Plastic” program, participants are rewarded with food baskets in return for each bag plastic collected. The success was enormous, with over 15 tons of household plastic and plastic in the environment collected. This program also creates a level of pride to the local communities, helping them link plastic and other waste to the health of their waters, and the impacts created by them.
Above: "Harvest Plastic" Rice Bags
Due to the characteristics of bottom-up approaches and their ability to target specific problems, the number of bottom-up projects that aim to solve the plastic problem far outweigh the efforts made from top-down approaches. The scale of bottom-up approaches also differs, and the Water Rising and Water Falling festivals are relatively small and confined to the Tonle Sap lake at the current stage, but have already received local and national government support due to the positive energy they bring to the communities. Thus supporting future government level (Top Down) policies related to plastics.
An example of a large-scale Bottom Up approach could be the Ocean Cleanup Project, which aims to develop technologies that make cleaning up the oceans a possibility. They are currently in the evaluation stage of their System 002 (they nicknamed it Jenny), in the five months of testing, the device collected 40,273kg (40 tons) of plastics (or 1/2500th of the Great Pacific Garbage Patch) and showing better results than System 001 which broke during testing. It should be noted that the system design is incomplete, with design work for System 003 already under way. For more information visit The Ocean Cleanup site, where you can find their latest development in addition to many scientific white papers they published related to all aspects of their methodology and design.
Above: Ocean Cleanup Project System 002
Westbound Rower Education Week 28: How we can use Data and Global Alert Tool
Digitisation of data has allowed for many improvements in our lives. By transforming formerly analog systems into digital systems, we are now capable of collecting, storing, and analysing an ever-growing amount of data from systematic-sources and open-sources. The result is the growth in the idea of data-based decision making in many parts of societal functions, including environmental management. It is almost certain we are connected to data every day, and the wealth of data and information are quickly made available through the internet. With just a few clicks, anybody with access to the internet can follow, often in near-real time, events like extreme weather phenomena or Erden’s track across the Pacific.
Erden’s Ocean Crossing relies heavily on data. For example, Erden uses meteorological data from satellites and ocean current models to navigate the ocean. The GPS coordinates that are recorded on the Westbound Row is also a type of data, allowing us to first keep track of Erden and his rowboat, and perhaps later when it could be used in GIS (Geographic Information Systems), like in our StoryMap where the GPS data can be visualised on a map and for other kinds of spatial analysis. As a citizen scientist, Erden is also collecting sound data for beaked whales, visual and observational data for birds and other marine life, in addition to recording the conditions of the ocean regarding ocean plastic.
Now, if we discuss data mainly in the field of science, the “data” is simply different types of information can be formatted and analysed in a particular manner. Which after analysis can give us a better understanding about the topic of study. Models on the other hand are a data product, where many types of data are coupled together to provide an understanding of temporal changes over time. If a projection of the past using such models are achieved, we can say there are some predictive capabilities to the model and may provide some insight into how a variable or topic can change over time. In the case of Erden’s use of numerical Ocean Current Models, it is common to find variables such as depth, salinity, heat (energy), sea surface temperature, specific humidity, wind speeds and direction, current speed and direction, and precipitation to name a few. Numerical data can also be visualised in either vector format or raster format, making it easier to visually identify patterns and make decisions based on model data outputs.
Peer-reviewed and verified predictive modelling allows for various simulations, and Erden uses this to his advantage because scientists now have the capability, to simulate Erden’s movement with ocean currents starting from a certain geographic location and time. These simulate Erden’s potential movements based on the ocean and provide suitable vectors for Erden to follow to reach his destination. Erden’s most recent course correction to Guam also required such simulation, taking into account data of Erden’s rowboat dynamics and sea anchor (para-anchor). An example of model outputs can be seen below, where the blue line provides the predicted drift, while the grey lines provide an area of uncertainty.
Above: Ocean Model simulation output for Erden’s course correction to Guam.
Our understanding of ocean plastic and how they interact and stay within ocean gyre systems are also based on such simulations, and you can also try it out yourselves! A cool model that is simple to use and allows you to simulate where plastic will go if it reaches the ocean from a temporal range of months to up to 10 years. Just click on a coastline and see where plastic may end up in the ocean based on validated ocean model data!
In the context of ocean plastic pollution management data is also incredibly useful. Models and data output such as the one from Adrift can be used to visualise the issue, then used to coordinate clean up strategies like that of the Ocean Clean Up with the capture systems a large net being pulled behind two boats and relying on ocean currents to capture waste plastic. However, on land, the concept of plastic hotspots can be equally useful in coordinate plastic management strategies on land.
Plastic and other trash hotspots are visually identifiable and where citizen scientists’ contribution to data collection are invaluable to our current understanding of the issue and where to increase our waste management efforts. A mobile and online tool which attempts to track and identify this plastic and trash hotspots is the Global Alert App, created by Ocean Recovery Alliance. The app does not alert the users about the hotspots, but rather alerts municipalities and governments about the location of the hotspots. Partly funded by the World Bank’s Global Partnership for Oceans, the Global Alert is a tool to broaden awareness, and a database of information which helps to address issues of plastic pollution in our waters.
Above: Global Alert Online Tool
The Global Alert online tool and mobile app allows users to document, and map plastic pollution hotspots, report the plastic pollution levels in their rivers, coastlines, and other locations where plastic is likely to end up in the ocean. These hotspot locations are visualise on a map which could be queried and analysed in the process of developing better plastic management strategies. Users may upload photos to Global Alert and record relevant information about the volume of trash found at individual hotspots.
Recall the Water Rising and Water Falling Festival in Cambodia discussed as a bottom-up solution to plastic waste. The Global Alert app was also used during this festival, and the data was even used to coordinate clean-up efforts in areas where concern citizens reported trash hotspots in waterways. The interest from communities demonstrated via the data provided by Global Alert, inspired the government to implement a fine for illegal dumping of rubbish and plastics into their waterways. Analysis of data within the Global Alert database, key points of plastic flows were identified, and nets were installed to capture the plastic as water flows through.
Above: Nusa Pendia, Bali Indonesia
In Nusa Pendia, Bali Indonesia, Data from Global Alert increased knowledge of plastic pollution of its local region. After analysing the Global Alert app data collected by the local community, schools, and NGOs, Nusa Pendia Island was able to identify a 9km shoreline on the north of the island they identified as a trash hotspot. It was realised the waste collection services at the time only serviced 2km of the shoreline, and continue to find solutions to fund services for the entire shoreline. Using the data, schools organised clean-up events arranged alongside the Nusa Penida Youth Forum, generating social media momentum highlighting the cause.
Click here to check out the Global Alert online tool. On this website you can look and analyse existing trash hotspots. You can also download the Global Alert app is made available for both Android and iOS, and can be freely downloaded from their respective app stores. Here you can add data to the Global Alert tool, and report plastic and trash hotspots in your community.
Westbound Rower Education Week 31: Rising Sea Level
Other than rising temperatures, rising sea levels are another consequence of human activities and climate change. the Intergovernmental Panel on Climate Change (IPCC) recently released a report signalling a significant increase of coastal flooding over the next 30 years, offering near-term projections for the first time. This report, which mainly covers the projected changes along the coastline of the United States, suggests an average sea level rise of 10-12 inches (25-30cm) above today’s levels by 2050. While this does not seem like much, this change should not be underestimated as the additional energy stored in the ocean from rising sea levels will further exacerbate the current rate and magnitude of climate change. The report also came with a Sea level Projection tool, which projects the estimated change in sea level based on our current understanding and climate model scenarios up till 2150. Check out what the report has to say about the closest coastline to you!
Above: IPCC 6th Assessment Report Sea level Projections
We can discuss sea level rise as global mean sea level, or by regional sea level. The first provides an overview of the interactions between three processes, including ice melt, thermal expansion, and land-water storage on the overall change in the total volume of the ocean. The latter involves sea level change in the more regional scale and is the rise in sea level relative to the coast and therefore more important to coastal regions and communities when assessing the potential impacts on the coastline. A few more variables are included in the regional sea level change, including more short-term effects like storm surges, sterodynamic variability, and subsidence of the land in addition the three factors mentioned earlier.
As you can imagine, our rising sea levels are a direct product of the mentioned processes and is not only because of additional water being added to the ocean via melting ice. It is also a common misconception that all melting ice leads to sea-level rise, which is untrue as melting sea-ice has no effect on the sea level change. Rather it is the melting ice on land (glaciers, ice and snow on mountains etc.) which adds volume into the ocean. The increased volume of ocean water, then allows for more energy to be trapped within the ocean and would affect the ocean circulation system and allow for thermal expansion of the ocean. Thermal expansion is the tendency for something to change its shape, volume and density in response to change in temperature or energy. This process is not only limited to water, but it also happens to air (e.g hot air balloons), buildings and other infrastructure. You can see a demonstration of this in the following video, now imagine the same happening for the ocean, and it is not difficult to see how the thermal expansion and sea-level rise are closely related.
Above: Thermal Expansion of water
Glaciers and ice sheets are vast stores of ice on land and exists at temperatures near the melting point of ice, and therefore highly vulnerable to any temperature change. These environments holds the trapped ice on land, and estimates suggest it holds enough volume to raise the global mean sea level by over 60 metres in the unlikely scenario all of it melts and runs into the ocean. Our current understanding, melting of these land ice had a disproportional influence towards sea level rise, with nearly half of all sea level rise attributed to these sources.
Today glaciers are closely studied, and its mass balance (snowfall minus runoff and calving) are used to measure the growth or retreat of a glacier. As you can imagine nearly all glaciers and ice sheets are retreating. However, there is one exception, the Crater Glacier (or Tulutson Glacier) on Mount St. Helens that formed in the crater after the 1980 volcanic eruption which blow off the north side of the mountain. This glacier is the geologically youngest glacier today, and still growing at a rate of 5m (15 ft) in thickness and advances up to 1m per day!
Above: The Crater Glacier
At the regional scale, things are slightly different because the magnitude of sea level rise is almost always greater than the global mean sea level change because of the smaller scale changes which are regional specific. Sterodynamic changes describes the constant exchange of matter and energy between the air and ocean. For example, precipitation freshens up the water and evaporation makes the ocean more salty. If you recall from previous weeks of content the change in salinity also affects the density of the water and regional ocean currents. The easterly trade winds that blow over the equatorial Pacific drives the currents from east to west. Erden also makes use of this natural phenomena to row across the Pacific, but it does have implications on sea level rise because surface currents push the sea water towards Asia, piling up to the west so the sea level is normally in the Western Pacific than the Eastern Pacific. For example, the sea level at Papua New Guinea is normally 1-2 feet (30-60cm) higher than at the coast of Peru, but we are experiencing El Nino events, the sea level flattens out because of the weaker easterly trade winds. Notice the difference in colours between the East and West Pacific in the heat map of below!
Above: Regional Mean Sea Level Trends (1993-2017)
Storage of water on land plays a more significant role than on global mean sea level rise and again this is closely related to human activity. Many coastal regions are much less permeable than it was historically due to the urban infrastructure, therefore less water could be stored in the soil and more water runs into the ocean. Interestingly, the effects of dams and reservoir have the opposite effect, where delivery of water form rivers to oceans are reduced and being a minor contribution to a decrease in sea level.
Subsidence is the describes land or an object that is sinking along their vertical plane and could be caused by natural processes and human activities. A major cause of land subsidence is the extraction of groundwater due to rapid urbanisation and population growth of cities. Some studies have also suggested the weight of buildings have also impacted the level of subsidence of the region by compacting the natural sediment at the shallow layers . It should be noted that many cities and megacities are located along coastlines, for example, Tokyo, Jakarta, Bangkok and New Orleans. Natural occurrences of subsidence are related to plate tectonic and their interaction as they push or pull away from one another, forcing one of the plates to sink into the mantle.
Above: Land subsidence form a multi-sectoral perspective
Sea level rise poses a great threat to many of the coastal cities which are still growing. Small island nations are also extremely vulnerable to sea level rise as many of these islands already record increasing annual flood events. The impacts vary from country to country and the adaption methods to increase resilience from sea level rise are just as varied. Next week we will continue this topic and look at some of the impacts and measures countries and cities are implementing to reduce the effects of the rising ocean.
Westbound Rower Education Week 32: Innovative adaptations for Sea Level Rise
The data and findings reported in the Intergovernmental Panel on Climate Change Assessment Report 6 detailed the potential rise of the global mean sea between 20-30cm by 2050, which would continue to increase past the end of the 21st century. All coastal countries and cities will be affected by sea level rise, but some countries populations are more vulnerable to the impacts due to the geographic limitations, and in some cases socio-economic limitations are also a factor. For example, low lying countries such as the Netherlands and the Maldives are both at high risk of being submerged by the ocean in the future, but each country has its own measures for adapting and increasing resiliency to impacts of sea level rise.
Above: Elevation Map of the Netherlands
The history of the Netherlands is strongly linked to its distinctive orography, namely it’s lack of hills or mountains, and because of it the country has always maintained a love-hate relationship with the water that surrounds it. Flat areas of land in the country, in addition to the canals, rivers and unique waterways have led the country to become one of the biggest exporters of agricultural produce in the world. However, the lowland country has continuously faced hazards such as floods from overflowing rivers, and high tides. Which is also precisely where the name of the country originated from, “Netherlands” translating loosely to “lowland” or “low territory”.
To managing this problem, the Dutch developed the system to gain ground on the sea and the inland lakes, a system they call Ploder. A Ploder is a system that partitions the water by using dikes, and then draining the stagnant water within the dykes to dry the land. If the land surface to be reclaimed is above the low tide level, water could be drained through gates. Where the land is below the low-tide level, as in the case of the Netherlands, the water must be pumped out over the dikes. Some areas of the countries have redirected sediment-rich rivers to build up the ploder area relative to sea level, and would facilitate more passive methods of draining, and showing an early mastery of land reclamation, drainage and irrigation systems. However, when these methods became less effective and the ploder became more swampy, new techniques were needed to remove the water. They began to use windmills to pump water into exit ponds, and when villages began to organise themselves to manage the water the first form of governance in the Netherlands, Watrerschappen was formed. The Watrerschappen, consists of government agencies responsible for managing water barriers (dikes), waterways, water quality, controlled flooding among other water related functions. Today, there are more than 3000 ploders in the Netherlands and mills remain a characteristic element of the Dutch landscape and rich history.
Above: A Ploder
The struggle with the sea levels continued and in 1953, the country suffered one of its greatest natural disasters as storms surges caused unprecedent rises in sea levels which flooded 8% of the entire country with over 1800 lives lost. The recovery response led to the formation of the Delta Project, a mega project which aimed to control the river delta of the Rhine and Meuse Rivers and regulating water exchange between the North Sea and the Eastern Scheldt using a series of gates, locks, dikes and also the two-mile long Schelde East Barrier which can close in the scenario of an approaching storm. The Delta Project was a cumulation of over 40 years of work and a project which received up to 4.5 billion Euros in investments. It is still one of the most advanced storm surge barriers to date, and its functions have translated into improvements in the region’s socio-economic development as well as boosting tourism in the region.
Above: The Eastern Scheldt Storm Surge Barrier
Climate change has made urban and water management ever more difficult in the near future, as the current climate models suggest that the global average sea level my rise up to 1.1m (3.5 ft) under the high emission scenario RCP8.5. It should be noted that in all infrastructure projects, the high emission scenarios are always used in planning and design to better prepare for the future climate and associated conditions. The Delta Project was rated to withstand the effects of climate change up to 200 years from current times, with the assumption that regional sea levels continue to rise by 5mm per year. But are these efforts enough?
Above: The Floating Dairy Farm in Rotterdam
Other innovative adaptation strategies were to turn farmland into floating farms, as a proof of concept, the first floating dairy farm opened in Rotterdam in 2019, with dairy products sold in stores all over the Netherlands. The aim of the project shows a new direction for urban agriculture with lower impact on resources, but more importantly it reimagines the possibilities of floating architecture and sustainable development in a country where land is gradually becoming scarcer.
Above: The Maldives location
The Maldives is a nation of 1192 islands that spans across the equator in the Indian Ocean. The entire nation covers an area of approximately 90,000 square kilometres, but only 298 square kilometres of the total is dry land. Less than a fifth of the islands in the country are inhabited, the selected few habited islands on the atolls are built with for resorts while others are used for industry and agriculture. Like the Netherlands, the Maldives is another low-lying country, with more than 80 percent of its islands standing less than 1 metre above sea level, making the Maldives the country with the lowest terrain of any country, and particularly vulnerable to sea level rise. Our current models and climate change direction suggests a very real possibility that most of the land area of the country will be underwater by 2100.
The impacts from sea level rise are also expected to affect islands home to local Maldivians far more than the resort islands. The former president of the Maldives and a leading voice of climate change equity, Mohammed Nasheed, told the press more than 90% of the islands have severe erosion and 97% of the country no longer has fresh ground water. A more recent study and observations has also shown some of the islands have lost over 130ft (nearly 40 metres) of beach to the ocean in the past 5 years. This urgent situation is not a new for the country, and the film The Island President (2012) follows the story of Mohammed Nasheed, and his mission to protect the country from the rising ocean and other impacts of climate change.
Above: The Island President (Full documentary)
The unique circumstance of the Maldives have made their struggle extremely difficult as the only realistic solution since the 1990s was to build new islands or elevate existing islands to relieve the population who are driven off lower lying islands. An example of an artificial island in the Maldives is Hulhumalé, which was built by pumping sand from the sea floor onto a submerged coral platform. Hulhumalé is raised to 2 metres above sea level and is more than twice as high as the capital of the Maldives, Malé. Originally designed to relieve population crowding on the Malé, the construction began in 1997, and its development over time could be clearly seen via satellite imagery. Since 1997, Hulhumalé has grown to cover 4 square kilometres, making it the fourth largest island in the Maldives and has proven to be an option for evacuations during typhoons and storm surges.
Above: Comparison of Satellite Imagery over Malé and Hulhumalé (1997 – 2020)
The Maldives is also currently developing a floating city, The Maldives Floating City, designed in collaboration with Dutch Docklands, a leader in floating development and infrastructure based in the Netherlands. This first-of-its-kind of floating city will be easily accessible and will be based in a lagoon just 10 minutes by boat from the capital city and its international airport. Another difference between this project is that no land reclamation and dredging would be required, thus having minimal impact on the island’s coral reefs. Instead, the natural coral atoll would serve as breakers below the water to lessen the impact of lagoon waves and would stabilise the floating structures on the surface. A network of bridges, docks and canals would provide access and connectivity with various segments of the floating city, with plans for a school and hospital to be eventually added. The Maldives Floating City will also have been powered by renewable, and designed to be as energy efficient through incorporation of smart grids within the Floating City and in homes. While these technologies call for a higher initial cost, it is far more sustainable in the long term.
The construction of the Maldives Floating City is due to start this year in 2022, and the will be completed in phases over the next 5 years. For now, all we have are conceptual images of what the Floating City would look like. Below is a short video of the launch event of the Maldives Floating City on 14th March, 2021 where you can learn more about the project from representatives of the Maldivian government and Dutch Docklands.
Above: Maldives Floating City Project Launch
The fight against climate change and rising sea levels must consider both mitigation and adaptation. Adaption measures alone in the long run will prove unsustainable as more and more resources will be needed to adapt too the changing environment. The long and complicated history the Netherlands had with the water surround it has made the country a leader in water management and coastal defences, often collaborating with other countries which are facing the same perils like the Maldives. While the Netherlands takes a more technological approach to mitigate and adapt to sea level rise, the Maldives takes a different approach and attempts to further enhance the ecosystem services from coral reefs as the former Maldivian president Mohamed Nasheed says, “ Our adaptation to climate change must not destroy nature but work with it, as the [Maldives] Floating City proposes. In the Maldives, we cannot stop the waves, we can rise with them.” Referencing the plans of growing new and existing reefs.