Increases in ocean acidity are damaging the first link in the food chain, a microorganism called coccolithophores. This is causing major impacts to marine species that rely on coccolithophores as their primary source of food.
Recent research from the Universitat Autonoma de Barcelona’s Institute of Environmental Science and Technology illustrates how ocean acidification is affecting coccolithophores, and thus, how ocean acidification is affecting the food chain as a whole.
Coccolithophores, part of the phytoplankton family, are single-celled plant-like marine microorganisms that are commonly found close to the surface of the ocean. Despite their microscopic size, coccolithophores play an important role in the marine food chain by serving as its foundation. Many small marine animals rely on coccolithophores as their primary source of food and energy. Even small fish and other organisms that do eat other things, like worms or small crustaceans, feed on coccolithophores when other sources of food are scarce. Marine animals obtain nutrition and energy from coccolithophores’ fat content, known as lipids.
Coccolithophores build protective scale-like platings around themselves known as coccoliths (the oval platings shown in the image to the right). These coccoliths are made of limestone (calcite). However, ocean acidification makes it much more difficult for organisms to build calcite shells.
A 2022 study conducted by researchers from the Universitat Autonoma de Barcelona’s Institute of Environmental Science and Technology, in collaboration with the Roscoff Marine Station of France, discovered that ocean acidification has significantly reduced coccolithophores’ ability to build shells, and decreased the nutrient content in their bodies. This has massive cascading effects throughout the food chain. Here’s what you need to know about it.
The researchers created a simulation of future climate conditions, causing ocean warming and triggering ocean acidification.
At first, the coccolithophores showed resilience to the increase of ocean temperatures and acidity. The researchers even observed an increase in their population.
As the experimental ocean acidity spiked, the researchers found that coccolithophore population growth halted as the organisms began to struggle to build their shells. The acidic conditions caused the coccolithophores’ protective platings (coccoliths) to collapse. While this may seem beneficial to organisms that eat coccolithophores (because this makes them easier to eat and digest), this breakdown of their shells comes with other negative consequences.
Researchers also discovered that when coccolithophores were exposed to acidified ocean conditions, the nutritional content in their bodies significantly decreased. As acidification worsens, this reduced nutrient content may have a detrimental impact on the food chain. Marine species that rely on coccolithophores for food, such as smaller fishes and zooplanktons, would be forced to feed on nutritionally deficient food.
Researchers concluded that as ocean acidification affects coccolithophores’ energy and nutrients, coccolithophores may also seek lower-acidity areas to try and slow ocean acidifications’ effects on their survival. This movement will pose an extra threat to marine species that rely on coccolithophores for food, as some may be unable to “follow” coccolithophores to lower-acidity conditions..
The images below show the comparison of healthy coccolithophores (a) and collapsed coccolithophores due to ocean acidification (b).
As climate change-driven ocean acidification and higher ocean temperatures continue to threaten various marine animals, some species are beginning to evolve in order to adapt to warmer, more acidic conditions. But does this evolution come at a price? A recent experiment from the University of Vermont, in collaboration with the University of Connecticut, the GEOMAR Helmholtz Center for Ocean Research in Germany, and the University of Colorado, Boulder, focuses on this question.
This March 2022 study analyzed how one copepod (a small crustacean species), Acartia tonsa, will likely evolve in order to adapt to warmer ocean temperatures and higher levels of carbon dioxide. However, these copepods’ resilience to climate change comes hand in hand with increased vulnerability to other stresses such as limited food sources.
Scientists from the University of Vermont conducted a laboratory experiment to understand the effects of ocean acidification on copepods, a group of small crustacean species that serve as a food source for many marine species. Copepods also act as an important biological control agent against mosquitos carrying human diseases.
Researchers artificially evolved 23 generations of Acartia tonsa, a copepod species, in order to study the effects of ocean acidification on copepod reproductive success. The results reveal that copepods can adapt fairly quickly to a warmer, acidified ocean ecosystem, but that this rapid evolution decreases the species’ genetic flexibility, which leads to increased vulnerability to other stresses.
Finding One:Copepods have the ability to quickly adapt to ocean acidification due to high genetic flexibility.
Copepods have the ability to become sexually mature and reproduce in just four to six weeks, making them a helpful organism to help scientists study evolution over shorter periods of time. This study utilizes copepods’ ability to reproduce and create new generations in a short period of time to analyze the effect of ocean acidification and warming on the health and reproductive success of twenty-three generations of copepods.
Scientists created an ecosystem that simulates future ocean conditions under climate change. They exposed thousands of copepods in multiple generations to the acidic environment and tracked their health and reproductive ability.
The study found that copepods showed resistance to ocean acidification and continued to thrive throughout twenty-three generations. This is due to copepods’ plasticity (genetic flexibility), or the ability to manipulate their genes, allowing them to adapt to environmental changes. This includes but is not limited to:
Ability to adapt to increasing temperatures in their environment
Ability to grow skeletons in an acidified environment
Ability to generate additional energy in order to adapt to the stress caused by ocean acidification.
Although the results provide optimism for the future of copepod populations, the next experiment demonstrates the cost of this generational adaptability to copepods’ health and reproduction.
Finding Two: Rapid evolution in order to evolve to ocean acidification decreases copepods’ ability to adapt to other environmental stressors in the future.
After twenty-three generations of copepods living in an acidified environment, scientists reintroduced some of the copepods in the less acidic environment – the current acidity level of the ocean today. The new generations of copepods that were reintroduced to this less acidic environment did re-adapt to these new conditions – but with lowered ability to respond to other kinds of stressors like a limited food supply.
The researchers explained that, in an effort to adapt quickly to acidified conditions, the copepods lost genetic flexibility (known as “phenotypic plasticity”), their ability to genetically adapt to different environmental conditions.
The copepods genetically adapted to high acidity conditions, which left them all with similar genetic makeup. This left them less able to adapt to new stressors, such as a lowered food supply. Copepods in the lower-acidity environment their ancestors had come from had smaller populations and were generally less healthy.
The scientists concluded that, while there is hope for copepods and other ocean animals to adapt to increased ocean acidity and warming ocean, there may be hidden costs for those species as a result of rapid evolution.
Brennan et al. “Loss of transcriptional plasticity but sustained adaptive capacity after adaptation to global change conditions in a marine copepod.” Nature, March 3, 2022, DOI: 10.1038/s41467-022-28742-6.
Did you know that the sunscreen you apply doesn’t always stay on your skin? In fact, when we swim (or even shower), the sunscreen you’ve applied throughout the day washes off into waterways and often ends up in the ocean. In fact, around 6000 tons of sunscreen washes off into reef areas every year, according to scientists. That’s equal to the weight of nearly 50 blue whales!
While we depend on sunscreen to protect us from skin damage and disease, many sunscreens actually cause great harm to marine ecosystems. And with 80% of corals in the Caribbean lost in the last 50 years, in part due to pollution, it’s more important now than ever before to ensure we take steps to avoid damaging these important organisms further.
But how exactly does sunscreen damage coral reefs, and what can we do about it? Let’s dive in.
Protection for People, Harm to Marine Life
Researchers estimate that approximately 10%, if not more, of coral reefs around the world are threatened by sunscreen. The areas feeling the brunt of the damage are highly-tourested areas like Hawaii and the Caribbean, where thousands of tourists swim every day, leaving sunscreen behind them.
So, how is sunscreen killing coral reefs? There are two main types of sunscreen: physical and chemical. Unfortunately, both types of sunscreen can cause harm to coral and other types of marine life.
Physical sunscreen is made of minerals that sit on top of your skin and reflect the sun’s rays. The main minerals used for this purpose are titanium dioxide and zinc oxide, which can wash off into the water. In fact, studies estimate that the average tourists on a Mediterranean beach release 4kg of titanium dioxide in a single day. When these minerals are very small (called “nanoparticles”), they can be absorbed by coral and cause severe damage.
A 2018 study found that zinc oxide nanoparticles cause extreme coral bleaching. This is because the zinc interferes with symbiosis between coral and other organisms, which leads to bleaching over time. Zinc oxide and titanium dioxide nanoparticles in the ocean may also cause chemical reactions to occur that result in hydrogen peroxide, which bleaches coral.
Chemical sunscreens contain chemicals that absorb into the skin, and then absorb UV rays before they can hit your skin. The active ingredients include “UV filtering” chemicals avobenzone, octinoxate, and oxybenzone. These are extremely potent and toxic to marine animals including coral.
New Research: How Does Sunscreen Harm Coral Reefs?
While scientists have known that oxybenzone damages coral reefs for a while, they did not know exactly how the chemical was causing harm. In May 2022, researchers at Stanford released a study that explored oxybenzone’s effects on sea anemone, an organism that’s closely related to corals.
The researchers found that when oxybenzone was exposed to light and a sugar found in anemone tissue, not only did it kill the anemone, but the chemical metabolized into another molecule, releasing free radicals that kill coral. Sea anemones exposed to oxybenzone and sunlight died around one-three weeks after exposure.
Finally, preservatives used in sunscreen to help the product last longer can also have toxic effects on both humans and coral. For example, parabens, a class of preservatives, are used in many sunscreens to prevent the growth of bacteria and mold. However, parabens can wash off into the environment, and have been found in a wide variety of organisms all over the world, from fish to marine mammals and birds. Studies show that parabens can disrupt the hormones of a variety of animals, including humans.
Parabens can also cause viral infections in zooxanthellae, symbiotic algae that live in healthy coral tissue and provide it with nutrients. A 2008 study showed that, because of these viral infections, coral bleaching occurred within a few hours to a few days of exposure to even very small amounts of sunscreen.
Does Sunscreen Harm Other Types of Ecosystems?
It’s not just marine life that’s impacted by sunscreen. When we shower, sunscreen is often washed off into wastewater, which makes its way into fresh bodies of water. However, due to the extreme variety of aquatic ecosystems throughout the world, the specific impacts of sunscreen in aquatic environments are still unknown.
Many experts are calling for more research into the impacts of sunscreen on non-marine ecosystems. In August 2022, the National Academies of Sciences, Engineering and Medicine published a report calling on the US EPA to conduct further studies into the risks that UV filters cause to aquatic ecosystems (including freshwater). They explain that while we know UV filters have been found in water, sediment and even animal tissue in a variety of ecosystems, we need more information to understand the extent of the impacts they’re having on a variety of aquatic organisms.
Government attention to the issue of sunscreen killing coral reefs is not limited to scientific data gathering, however. Next, we’ll review how a few governments have taken a stab at protecting coral reefs and other marine organisms from toxic sunscreen ingredients.
Legislation: Bans on Reef-Toxic Sunscreen
In response to concerns about the toxic effects of sunscreen on coral reefs and the intense reduction in living coral reefs, several governments have passed legislation banning sunscreen containing oxybenzone and octinoxate.
Hawaii was the first state to ban harmful sunscreens with the passage of a bill in 2018 that banned oxybenzone and octinoxate sunscreens. In 2021, the Hawaii State Legislature passed another bill that banned two more harmful chemicals in sunscreen, avobenzone and octocrylene.
Other local and federal governments have also banned harmful sunscreens, including:
What You Can Do to Protect the Ocean from Harmful Sunscreen
There are a few things you can do to avoid putting more harmful sunscreen into the ocean.
1. Use other forms of sun protection. While sunscreen is, of course, a necessary product to protect ourselves from harmful ultraviolet rays, it should really be a last resort. Instead, use UV-protective clothing like a sun shirt to reduce the amount of sun your skin is exposed to. You can also try and spend time in the shade to protect your skin.
2. Use reef-safe sunscreen. When you do need to use sunscreen, make sure it’s a reef-safe sunscreen. First, avoid spray-on (aerosol) sunscreen, as the spray disperses into the environment much more easily than a cream, and often contains harmful chemicals. Instead, opt for a mineral sunscreen with zinc oxide and titanium dioxide that aren’t nanoparticles (if the packaging doesn’t explicitly say “micro-sized” or “non-nano,” you can be pretty sure it contains harmful nano-sized particles).
To figure out if a sunscreen is truly reef friendly, look at the label. Make sure to avoid these chemicals:
Finally, while sunscreen in the ocean is clearly harming coral reefs, we must also take into consideration the other threats to coral reefs, including overfishing and climate change’s rising temperatures. Changing to a reef-safe sunscreen may make a small dent, but we must curb climate change in order to truly protect coral reefs and other marine life.
Rising ocean acidity is threatening the population of the most common type of plankton, known as diatoms, one of the main oxygen producers on the planet and the primary food source for all marine life. Despite previous beliefs that diatoms actually benefit from ocean acidification, new research from the Helmholtz Centre for Ocean Research (GEOMAR) shows that diatom populations are extremely vulnerable to the effects of ocean acidification. Continue reading for a summary of the paper’s findings.
How Ocean Acidification Reduces Diatom Populations
In past years, scientists believed that diatoms are less affected than other marine organisms by the effects of ocean acidification. This was because diatoms rely on silica minerals to build their shells, rather than calcium carbonate, a substance that many other marine organisms rely on to build their shells and that is reduced by ocean acidification. In fact, some scientists previously argued that ocean acidification aids diatoms by increasing their ability to photosynthesize, and thus increasing diatom populations’ growth.
But, in a recent analysis, scientists explain how ocean acidification may reduce the population of diatoms at an alarming rate. Here’s what you need to know about it.
The study researched the effects of ocean acidification on the dissolution of the silicon shell of diatoms. The results show that acidified seawater significantly slowed the ability of diatoms to dissolve their silicon shells, ultimately leading to a lowered ability to gain nutrients through photosynthesis.
The most common negative impact of ocean acidification on shell-forming marine species using calcium carbonates, such as oysters, clams, mussels, and corals, is a reduction in their capacity to form shells due to a lack of carbonate ions in more acidified seawater. While this chemical imbalance was not believed to affect diatoms due to their silicon-based shells, ocean acidification actually threatens diatoms in another way.
GEOMAR Helmholtz Centre for Ocean Research Kiel researchers used data from huge test tubes known as Mesocosms. These tubes were placed in different ocean biomes all around the world. Mesocosms can contain a large volume of ocean water inside, allowing researchers to manipulate the water parameters, such as increasing or decreasing the acidity level without harming the ocean ecosystem outside.
Using an Earth system model, the researchers utilized the collected data to simulate the negative effects of ocean acidification on diatoms in the future, on a worldwide scale.
Researchers discovered that acidified seawater slows the ability of diatoms to dissolve their silicon shells, which forces them to sink into the deeper parts of the ocean. Because of this, the abundance of diatoms on the ocean surface is lowered.
Researchers concluded that since diatoms needed to be at the surface water to get light to renew their shells, forcing them to sink may significantly decrease their population around the world at an alarming rate.
Rising ocean acidity is affecting the development of different types of marine species, such as sea urchins and brightly-colored reef fish.
A recent study shows how sea urchin development is affected by ocean acidification. (more…)
The Great Barrier Reef is experiencing massive coral bleaching events due to ocean acidification, which negatively affects the development of brightly-colored fish in the reef. (more…)
Study Shows How Ocean Acidification Affects Sea Urchin Early Stage Development
Ocean acidification has a significant negative impact on marine species and ecosystems. A recent study shows how ocean acidification affects the early development stages of some marine species, such as sea urchins. Here’s what you need to know about it.
The study researched the effects of pH on sea urchin’s development and transition from fertilization to juveniles. The result shows that low pH levels significantly affected the growth and mortality of the urchin’s larval stage. Even small changes in ocean pH (on the scale of .1) can have major impacts.
Larval Stage: Effects of Ocean Acidification
Sea urchin larvae were exposed to a 7.2 pH level (compared to the current ocean’s actual pH of 8.1). The sea urchins exposed to this pH exhibited the following characteristics:
Higher mortality rates.
Higher abnormality rates.
Lower growth rates.
The metabolism of sea urchin larvae exposed to a 7.2 pH level increased as well. The researchers believe that because of this, the urchins may be using additional energy to boost metabolic function, which might limit their growth rates. In other words, the sea urchins adapt to ocean acidification by shifting their energy to boost metabolic function, rather than other important functionalities. Researchers believe that this shift in energy may be what’s causing mortality and abnormalities throughout their development stages.
Settlement Stage
Researchers discovered that prolonged exposure to a 7.7 pH level significantly delayed the settlement of sea urchin larvae, an important process during which larvae settle to the ocean floor where they will eventually begin their adult life stages.
However, when the sea urchin larvae were placed under a suitable algal substrate for the settlement stage, the researchers found that the larvae remained unaffected by 7.7 pH levels. This shows that algae may help reduce the effects of ocean acidification on sea urchin larvae.
Metamorphosis Stage
The study shows that in the metamorphosis stage, all the sea urchins that were grown at a 7.2 pH level failed to metamorphose. The researchers concluded that sea urchins that are exposed to low pH levels throughout their early development stages may find it hard to impossible to achieve metamorphosis.
However, the study also shows that 30% of the sea urchin larvae that were grown at a 7.6 pH level achieved the metamorphosis stage. This shows the large impact of even a pH change of .4, compared to the 7.2 pH group of urchins.
Ocean Acidification Affects Brightly-Colored Fish Development Through Continuous Coral Bleaching
The Great Barrier Reef is experiencing massive coral bleaching events due to ocean acidification, which negatively affects the development of fish’s color in the reef. Here’s all you need to know about the study.
In the span of just three decades, the effects of ocean acidification and global warming have caused the Great Barrier Reef to lose thousands of its coral species. This phenomenon is commonly known as massive coral bleaching events. As a result of this, the number of brightly-colored fish in the Great Barrier Reef is decreasing.
According to the study, the number of different types of brightly-colored fish in the Great Barrier Reef has declined significantly since the massive coral bleaching event of 1998. Scientists believe that the composition of the seafloor (texture, colors, patterns) affects the development of the coloration of fish.
Reef fishes developed coloration to protect themselves from predators by adapting to the different coral structures and compositions. Fish would find it useless to produce vibrant colorations in the absence of coral compositions.
The study concluded that the loss of vibrant composition and structure of the seafloor due to the massive coral bleaching events has a significant relationship to the inability of many fish to develop their vibrant colors.
Ocean acidification occurs when the pH level of seawater decreases. This is most frequently caused by the ocean absorbing excess CO2 from the atmosphere. By evaluating an ocean acidification case study, we can get a sense of how damaging ocean acidification currently is, and what measures can be implemented to prevent further damage.
This article will outline a case study on how ocean acidification affects coral reefs in the Pacific Basin, as well as proposed solutions to prevent further damage.
This study, Lebrec et al. 2019, was originally published in the journal “Regional Studies in Marine Science.” It discusses the effects of ocean acidification on coral reefs in the Pacific Basin, where mass coral bleaching has occurred. The case study highlights five coral reef ecosystems in the Pacific basin, which are found in the following locations:
Ryukyu Archipelago, Japan
Palau
Hawaii
Marshall Islands
American Samoa
Locations of coral reef ecosystems highlighted for the case study Source: Lebrec et al. 2019
The case study evaluates the impact of ocean acidification on the above locations and proposes solutions to prevent ocean acidification and other ocean stressors from causing further damage to coral reefs.
Ocean acidification negatively affects the coral reefs in the Pacific Basin by reducing the amount of calcium carbonate that is essential to coral reef skeletal development and coral survival. This causes coral reef death.
The study highlights the importance of unique coral diversity in each of the five geographic locations, as well as the vital role coral reefs play in local communities and economies.
Hawaiian coral reefs are not just important to the tourism industry, but they also provide direct benefits to the community by sustaining fisheries and pharmaceutical production, which generate income through exportations. Hawaiian coral reefs also provide indirect benefits to the community by protecting coastal areas from storms. The economic value of coral reefs in Hawaii is about $455 million USD.
The Marshall Islands is the world’s most coral reef-dependent country. Most of their needs are met by the reef, including employment, nutrition, exportation, tourism, and protection against natural disasters.
The Ryukyu Archipelago is home to more than 360 species of corals, which makes it the world’s richest endemic coral reef. The archipelago’s coral reef plays an important role in its economy, generating $4.7 billion USD tourism revenue in a single year.
Palau is home to around 425 species of coral reef, which makes the country the most biodiverse coral reef in all of Micronesia. It provides 40% of the country’s employment, as over 90% of tourists that visit the island come for diving and snorkeling.
American Samoa is home to about 200 coral reef species, which is why the government established 6 major protected areas for coral reefs across the archipelago.
The locations in the case study are experiencing coral bleaching events due to the combined effects of different disasters, pollution, and ocean acidification. This affects these countries since all of them rely heavily on the services that coral reefs provide.
Hawaiian coral reefs are bleaching as a result of rising temperatures and ocean acidification, and certain coral reef species are recovering at a slower rate than expected.
Increasing temperatures have bleached over 90% of the coral reefs of Okinawa Island, which is part of the Ryukyu archipelago.
From 1997 to 1998, Palau had a GDP decline of about 3.3% due to intense coral bleaching events.
Coral reef bleaching in Airport reef, Tutuila, American Samoa Source: Coral Reef Watch/NOAA
Proposed Solutions to Fight Ocean Acidification-Related Bleaching
This case study provides 3 proposed solutions to fight ocean acidification and its damage to the coral reefs in the Pacific basin.
Adaptation promotes the resilience of coral reefs by initiating conservation regulations and the reforestation of coral reefs, and increasing coral reef protected areas.
Mitigation covers the reduction of carbon emissions at the global and local scales. This could be in the form of carbon taxation, an emissions trading system, or a cap-and-trade system.
Capacity Building focuses on promoting local research advancements and spreading education and awareness to the community, generating funds to improve coral reef conservation efforts, and creating local collaborative efforts to promote national policies that push for unified international policies.
Conclusions
This case study highlights the importance of coral reefs in the Pacific Basin and how the countries around it majorly depend on the services that the coral reefs provide. Understanding the impacts of ocean acidification on coral reefs in the Pacific basin can help us promote solutions to ensure their benefits to humans and ecosystems remain intact.
This case study is just a part of a much larger global issue of ocean acidification and its negative effects. There are many other countries around the world that are experiencing not only coral reef bleaching but also damage to marine animals and microorganisms that are essential to maintaining the ecological balance of the world. The case study emphasizes the importance of addressing ocean acidification, as if we fail, people all over the world will lose sources of food, income, and culture.
Ocean acidification occurs when the pH level of seawater decreases. This is most frequently caused by the ocean absorbing excess CO2 from the atmosphere, which increases as humans contribute more carbon to the atmosphere.
Ocean acidification has severe impacts on marine ecosystems, marine wildlife, and humans. While some researchers argue that ocean acidification can still be reversed to avoid these negative consequences, others disagree.
This article will examine the varying perspectives of experts and researchers on whether ocean acidification is reversible. We will also discuss proposed methods of reversal and the consequences we might face if we fail to reverse ocean acidification.
Ocean acidification began in the Industrial Revolution of the 19th century, and has been damaging marine life and ecosystems for centuries now. Today, ocean acidification continues to worsen. Experts in the field are working to identify whether it’s possible to return the ocean’s pH level, or acidity level, to its former condition in the pre-industrial period. In other words, scientists want to know: is ocean acidification reversible?
A Pessimistic Stance
The Secretariat of Convention of Biological Diversity (CBD) introduced a study in 2009 that focused on the impacts and trajectory of ocean acidification. The study collected 300 scientific reports related to ocean acidification and predicted that ocean acidity may increase by 150% by 2050. This increased acidity will likely cause irreversible damage to marine life and ecosystems. According to a 2009 press release, CBD Executive Secretary Ahmed Djoghlaf stated that “Ocean acidification is irreversible on timescales of at least tens of thousands of years.” This suggests that even with significant interventions, fully reversing ocean acidification will be impossible for our generation and beyond.
This difficulty in reversing acidification is due to the unprecedented speed with which ocean acidification has occurred; post-Industrial Revolution acidification happened 100 times faster than any previous change in acidity over the past 20 million years. Marine organisms and ecosystems are unable to adapt to increased acidity quickly enough, making it difficult to address or reverse.
Post-Industrial Revolution ocean acidification happened 100 times faster than any previous change in acidity over the past 20 million years. Source: IUCN
Another study was released in 2015, conducted by Germany’s Potsdam Institute for Climate Impact Research. The research focuses on Carbon Dioxide Removal (CDR) methodologies, which utilize technologies to boost the removal of atmospheric CO2,with the goal of reversing ocean acidification to pre-industrial levels. However, the researchers concluded that even if we achieve a 25 gigatons annual CO2 reduction through CDR, ocean acidification will be impossible to reverse to its pre-industrial condition until the year 2700.
Essentially, even after several centuries of carbon removal, oceans will still show the effects of current acidification.
An Optimistic Stance
In 2013, scientists from Lawrence Livermore National Laboratory conducted an experiment where they designed a sequestration method that works to absorb atmospheric CO2, create clean hydrogen fuels and release carbonate and bicarbonate, which improves alkalinity. The goal of this method is to increase alkalinization, or the chemical process of neutralizing acids to stabilize ocean acidity, in order to reverse acidification.
Another similar study released in 2016 focused on how to reduce ocean acidity through the introduction of an alkaline solution. Rebecca Albright of Stanford University and her team conducted anocean alkalinization experiment in a series of isolated lagoons surrounded by One Tree Reef, a portion of the southern Great Barrier Reef. The team developed a chemical solution made with a mixture of seawater, dye, and sodium hydroxide, which served as the alkaline (acid-neutralizing) solution that was deposited over the reef of the isolated lagoons. The experiment shows that changes in water chemistry through alkalinization successfully lower ocean acidity, and improve coral development.
However, the study suggests that ocean alkalinization alone is insufficient to reverse ocean acidification, and that in order to reverse ocean acidification fully, it is necessary to address excessive carbon emissions as well. While reversing ocean acidification may be part of a solution, reducing carbon emissions would address the root of the problem. This is why some argue that ocean acidification is reversible only if it is included in political initiatives that promote a wide reduction of carbon emissions.
Another study was released in 2021 that focuses on enhancing ocean alkalization by introducing experiments on a much larger scale: this time, to the whole Great Barrier Reef. In the experiment, 90,000 tons of alkaline solution were deposited into the Great Barrier Reef every three days for one year. The results reveal that the concentration of carbonate ions increased along the reef, a key indicator of ocean acidity levels. In fact, the experiment successfully reversed acidity levels to the conditions that existed four years ago, indicating that ocean acidification can be reversed on small scales or in small amounts, even if conditions cannot be returned to the pre-industrial conditions of 100 or more years ago. This is promising, as even if we cannot return the ocean to its original state, we may be able to stop the worst of ocean acidification’s effects from taking place.
Scientific Strategies to Reverse Ocean Acidification
Scientists and experts around the world have been studying ocean acidification and how to counter it for decades now. Several scientific methodologies that aim to reverse ocean acidification, including those mentioned above, have already been introduced. Here’s an overview of the methodologies and research that are being considered to reverse ocean acidification.
Enhanced Chemical Manipulation
One of the main methods scientists are researching to reduce ocean acidification is chemical manipulation. This includes ocean alkalization, or introducing a chemical source of alkaline to the seawater in order to stabilize the acidity levels. This method is believed to reduce ocean acidification at the local scale.
Because the cause of ocean acidification is the ocean’s absorption of excess CO2 from the atmosphere, one of the main strategies to alter increasing ocean acidification is to reduce carbon emissions globally. This could come through different climate-friendly initiatives and government policies, including but not limited to:
Switching to renewable energy sources
Implementation of carbon taxes
Driving low carbon vehicles, or using electric vehicles
Using bicycles and low-carbon forms of transport more often
Using energy-efficient appliances
Planting more trees
Surface Acidity Pumping
Several recent studies have suggested addressing ocean acidification with surface acidity pumping, the use of electrochemical pumping to relocate surface seawater acidity to the depths of the ocean. This method decreases the acidity level of the surface seawater by bringing up alkaline water from the bottom of the ocean, and then relocating surface acidity to the bottom. This strategy not only controls ocean acidification and benefits coral reefs’ health, but also allows the ocean to capture more atmospheric CO2, which may help to mitigate global warming.
Future Impacts of Ocean Acidification if Not Reversed
If the current rate of ocean acidification is not reversed, it will have a detrimental effect not just on the environment, but also on the global community. Here are some examples of how ocean acidification will affect humans, the economy, marine species, and ecosystems in the future.
Impact on People and the Economy
Impact on the Aquaculture Industry
Ocean acidification affects the development and survival of shell-forming marine animals, including oysters, clams, mussels, and many more. This variety of marine animals is widely produced, farmed, and consumed on the global seafood market. With these animals at risk, the shellfish and seafood market might collapse, which may cause job loss and economic fallout, especially in countries and regions that rely on shellfish farming.
Other fish may also be hard to find on the market as an indirect result of ocean acidification. Salmon and tuna, for example, are two of the most popular seafoods on the market. These fish rely on other smaller fish for food, such as sardines and anchovies. These smaller fish feed mostly on phytoplankton, which is one of the organisms most severely affected by ocean acidification. The imbalances ocean acidification creates in the ocean food chain have an impact on the survival of these popularly-marketed fish. If ocean acidification continues to worsen, much of the seafood that we not only enjoy, but also that generates income and employment and contributes to the economy may not be available decades or centuries from now.
Impact on the Tourism Industry
The tourism industry is one of the largest contributors to the world economy, but it is also threatened by ocean acidification’s impacts. For example, coral reefs attract tourists, which generates $36 billion for the global economy annually. Many regions rely on coral reefs to generate employment and business. Unfortunately, ocean acidification is already causing massive coral deaths in different parts of the world. If ocean acidification is not reversed, coral population declines will continue, which may create a negative effect on the tourism sector, resulting in job losses and business closures that will negatively impact the people that rely on them.
Impact on Marine Life and Ecosystems
Experts, researchers, and scientists have shown that ocean acidification is already creating detrimental impacts on different marine life and ecosystems. This includes the following discoveries:
Ocean acidification is negatively affecting the population and development of phytoplankton and diatoms.
Ocean acidification makes it difficult for coral to build their skeletons, which creates an ecological imbalance, and a non-habitable environment for reef fish species.
Ocean acidification negatively affects the capabilities of shell-forming marine species, such as clams, sea urchins, oysters, and mussels, to grow and develop their shells, making them more vulnerable.
Ocean acidification negatively affects salmon’s sense of smell and ability to detect danger.
All of the scientific discoveries listed above threaten the affected species, and may even lead to an increase in their mortality rate in the long run. Experts are concerned that if we do not stop or reverse ocean acidification, we may witness a repetition of the historical mass extinction that occurred 66 million years ago, when 75% of marine species became extinct due to an overly acidified ocean. If this happens in the future, the damaging impact of this may not only affect the marine life and ecosystem but all life on earth.
Key Takeaways
The possibility of reversing ocean acidification is uncertain. The main arguments can be summarized into three categories:
Some argue that ocean acidification is not reversible (especially not to pre-Industrial Revolution levels).
Some argue that we can slow ocean acidification down, but not reverse it completely.
Some argue that it is scientifically feasible to reduce acidification at least enough to avoid catastrophic consequences.
While ocean acidity levels likely cannot be returned to pre-Industrial Revolution levels, ocean acidification can be reduced on local scales to the acidity conditions of a few years ago (which is still a much-needed improvement).
Experts are working to find strategies to make this possible, although many of these strategies have not been tested on a larger scale. But one thing is certain about the question, is ocean acidification reversible: Reducing or reversing ocean acidification requires a global unified effort to reduce carbon emissions. If we succeed in achieving this, then the answer might be yes.
Ocean acidification occurs when the pH level of seawater decreases, which is most frequently caused by the ocean absorbing excess CO2 from the atmosphere. Ocean acidification has negative effects on a variety of ocean ecosystems and life forms, including whales.
This article will explain how whales are affected by ocean acidification and the importance of whales to ecosystems.
Whales are affected by ocean acidification in numerous ways.
First, whales may suffer from starvation and other diseases due to ocean acidification’s effects on their food supply. The increase of ocean acidity decreases the number of carbonate ions. This ion is essential to most shell-forming organisms including krill, which is the primary source of food for baleen whales, including blue whales and humpback whales. Without enough krill to sustain the whales, they can starve or seek alternate food sources, which may not give the appropriate nutrients the whales need, leading to malnutrition and other diseases.
There are also some studies theorizing that ocean acidification may affect the hearing abilities of whales and dolphins. This is important because hearing is crucial for whale communication. As the oceans become more acidic, the concentration of borate in the water decreases, which could affect the absorption of sound energy that whales rely on for communication. However, this theory was countered in a 2010 study, in which researchers from the Woods Hole Oceanographic Institution argued that acidification will only have a minimal effect on whales’ ability to communicate.
In summary, ocean acidification may contribute to decline in whale populations. This could become a serious problem for ocean ecosystems and climate change, as whales help to maintain balance in the ocean and atmosphere.
The Importance of Whales
Whales play a crucial role in maintaining balance in the ocean ecosystem, which helps marine life and people alike. Ocean acidification threatens the important services that whales provide. Here are some of the important roles of the world’s largest mammals.
Food Chain Guardians
In their place at the top of the food chain, whales play a very important role in maintaining the balance of the marine ecosystem and the supply of food in the ocean. For example, each day, a blue whale or a humpback whale can eat up to 40 million krill. Due to this massive appetite, overpopulation of krill is prevented, which helps preserve the ecological balance of the marine ecosystem.
Whales also act as fertilizer transporters in the ocean. Whales contribute to ocean fertilization through their deposits and urine. According to research, a sample of whale fecal matter contains 10 million times more iron than the amount of iron present in a sample of ocean water of the same weight. These nutrients are essential to the health and reproduction of different marine organisms, including phytoplankton (which help reduce ocean acidification). Because whales are migratory animals, they supply these nutrients to different ocean locations.
Climate Change Fighters
Phytoplankton usually thrive where whales are found. This is because whale deposits fertilize phytoplankton, which allows plankton to reproduce and thrive. Each year, phytoplankton absorb around 10-20 billion tons of CO2 from the atmosphere, and are considered the world’s largest producer of oxygen, as they help account for 70% of the world’s oxygen supply. Without the nutrients whales provide, phytoplankton might not flourish, which could greatly affect the ocean’s carbon cycle and increase ocean acidification.
Historical Whale Population Decline and Recovery
The population of whales started to decline in the 11th century as a result of the growing whaling industry. People hunted whales for oil and other products, including meat, baleen, and ambergris. This activity continued for centuries, causing the populations of different whale species to drop drastically, driving them to extinction.
In 1986, the International Whaling Commission (IWC) banned commercial whaling. Because of this, whales are finally able to recover and repopulate. Today, most of the whale species that experienced the decline are now showing some population recoveries. Here is the recent population status of some well-known whale species:
Humpback Whales
Today, the humpback whale population reaches about 80,000 as a result of global conservation efforts and policies.
Fin Whales
Fin whales were one of the most hunted whales during the whaling era of the 20th century, but today, their population is considered healthy, reaching about 75,000.
Blue Whales
Today, blue whale populations are still pushing for recovery. Even though their population is increasing, they are still listed as endangered. The current population of blue whales is between 10,000 – 25,000.
Though ocean acidification is not listed as one of the main sources of whale mortality today, several man-made factors are still causing death to different kinds of whales. This includes:
Globally, different organizations and government agencies are working to conserve and increase the population of whales. Since ocean ecosystem health is declining due to pollution, ocean acidification, and overfishing, whales and their sources of food are at risk. It is important that we work to conserve them, because they provide us with important services, including (indirectly) the air we breathe.
Here’s an overview of some whale conservation organizations:
World Wildlife Organization
For 50 years, the WWF has been running programs to protect whales. The organization participated in the petition banning commercial whaling in 1984.
The organization’s goal is to protect whales and dolphins using three methods:
Improving whale monitoring and mitigating bycatch (accidental entanglement in fishing traps)
Preventing ship strikes and reducing underwater noise pollution
Protecting whale habitats
Ocean Alliance
Ocean Alliance focuses on increasing public awareness of the importance of whales.
Through the production of 40 documentaries, the organization serves as the bridge between whales and the global community, allowing people to better understand whales and their purpose.
Whale and Dolphin Conservation
Whale and Dolphin Conservation has been working on whale conservation efforts for 30 years. The organization has been successful in its mission in various ways:
Stopping commercial whaling
Preventing and fighting against whale captivity
Preventing and reducing entanglements (bycatch)
Promoting sanctuaries and protected areas for whales and dolphins
Ocean acidification occurs when the pH level of seawater decreases, which is most frequently caused by the ocean absorbing excess CO2 from the atmosphere. Ocean acidification has negative effects on a variety of ocean ecosystems and life forms, including sea urchins.
This article will explore how sea urchins are affected by ocean acidification, as well as the importance of sea urchins to ecosystems, global cultures, and the economy.
How Are Sea Urchins Affected by Ocean Acidification?
Sea urchins are vulnerable to ocean acidification because rising acidity in seawater reduces the number of available carbonate ions, which are essential for building sea urchins’ shells, spines, and teeth. Here are some of the negative effects of ocean acidification on sea urchins.
Lowered Growth Rate of Sea Urchin Larvae
Because larval sea urchins are quite sensitive, ocean acidification affects the development of sea urchins at very early stages. According to a 2022 study, sea urchin larvae’s growth rate is lowered when they’re exposed to acidified water. Sea urchins, when exposed to lower pH seawater, need to use extra energy for other survival functions, including temperature self-regulation, leaving insufficient energy for them to use for their growth.
Increased Metabolism
Sea urchins feed on various types of marine organisms, including algae, planktons, and even kelp. Feeding is crucial to the growth, development, and survival of sea urchins. However, 2013 research discovered that increasing ocean acidity affects the metabolism of sea urchin larvae, forcing them to eat more than normal. A lower pH level reduces the capability of sea urchin larvae’s digestive enzymes, known as “gastric juice.” In order to attempt to make up for less effective digestion, sea urchin larvae exposed to acidification increased their feeding by as much as 33%. If this increased eating was not possible due to a lack of food, the sea urchin would suffer. Additionally, this increased energy devoted to eating reduces energy reserves for other vital functions such as growth and temperature self-regulation.
Increased Developmental Abnormalities and Mortality Rates
Ocean acidification forces sea urchins to reallocate their energy sources in order to adapt. This might sound positive, but experts have found that it is one of the causes of mortalities and abnormalities in sea urchins. In a 2022 experiment, sea urchin larvae were exposed to acidified water with a 7.2 pH level (much lower than the ocean’s current pH of 8.1). This showed a significant effect, causing abnormalities to the sea urchin’s structural development.
In the same experiment, when larval sea urchins were exposed to acidified water with a pH of 7.2, they were unable to grow into juvenile sea urchins. These abnormalities may threaten their survival rate.
Comparison of two sea urchins, where the sea urchin on the right is exposed to ocean current conditions, and the sea urchin on the left is exposed to ocean acidification. Source: Phys.org
The Importance of Sea Urchins
Sea urchins contribute to the ecological balance in the ocean ecosystem and provide products that are used in traditional cuisines. However, ocean acidification threatens sea urchin populations, and thus, the benefits they offer to ecosystems and people. Here are some of the ways sea urchins are important to ecosystems and people.
The Importance of Sea Urchins to the Ecosystem
Reef Gardeners
Sea urchins are herbivores and they feed on algae and other marine plants in the reef. Their feeding activities are essential to the balance of the reef because as they remove overgrown weeds and algae, they create room for corals to flourish. This provides more habitat for fish while also preventing the negative effects of overgrowing algae on the reef.
This service that sea urchins provide plays an essential role in maintaining a healthy and habitable marine ecosystem. They are great alternatives to the decreasing population of other algae controllers that are commonly overexploited by people, such as parrotfish and rabbitfish. If ocean acidification continues, the service of sea urchins to reef maintenance could be affected. Without sea urchins and other algae controllers, the reefs as we know them might become uninhabitable for many organisms in the future.
Sea urchins are a food source for several other species. Sea urchins’ high protein provides essential nutrients to animals that rely on this diet. Animal species that feed on sea urchins include:
Other shellfish, such as crabs and lobsters
Multiple fish species, such as sheephead wrasse and wolf eel
Sea otters
Seagulls
Some of these animals use sea urchins as their primary source of food, which is why the negative impact of ocean acidification doesn’t only affect sea urchins directly; it can also cause an indirect effect on species that rely on their services.
The Importance of Sea Urchins to People and the Economy
How Sea Urchins Benefit the Cultural Food Industry and Economy
Like any other commercialized shellfish on the market, sea urchins are also in demand in some countries’ food industry. Here is an overview of some of the countries that use sea urchins as part of their food industry.
Chile
Chile has a long tradition of eating sea urchins, as sea urchins have been part of Chilean food since the 1500s. Today, sea urchin is still a part of the Chilean diet. In 2002, Chile consumed around 3,000 tons of sea urchins, and in 2013, Chile ranked as the world’s largest supplier of fresh and frozen sea urchins and urchin roe. Sea urchins are not only a part of Chilean tradition and culture, but they also make a significant contribution to Chile’s economy today.
Eating sea urchins in Japan is traditional, with consumption accounting for around 90% of the global supply. Japan is the largest consumer of sea urchins in the world, where it is commonly eaten as sushi and sashimi, two of Japan’s most iconic dishes. The sea urchin also contributes significantly to Japan’s economy since the country is considered a major exporter of sea urchins globally.
The population of sea urchins may decline as a result of the effects of ocean acidification. This could have a damaging effect not only on the economic contribution of sea urchins, but also on culinary cultures that have been passed down for centuries.
Health Benefits from Sea Urchin in the Diet
Despite their threatening appearance, sea urchins can provide various health benefits and nutrients to people. Here are some examples:
Sea urchins are high in protein, which can help maintain and grow our muscles.
Sea urchins are also rich in dietary fibers that are good for digestion.
Sea urchins contain vitamin C and Zinc, which are great for the immune system.
They also contain vitamin A, which is good for our organs, such as the heart, kidneys, and lungs.
Just like other fish, sea urchins are rich in omega 3 fatty acids, which are useful for maintaining a healthy heart.
Sea urchins provide a variety of valuable benefits to the environment, wildlife, and humans. Several studies have already proven how the acidifying ocean affects their development, preventing them from thriving. This could alter the important services they provide that help in maintaining ecological balance. This is why it is essential to assure that sea urchins, like all other species, are protected from the damaging consequences of ocean acidification.
Ocean acidification occurs when the pH level of seawater decreases, which is most frequently caused by the ocean absorbing excess CO2 from the atmosphere. Ocean acidification has negative effects on a variety of ocean ecosystems and life forms, including salmon.
This article will explain how salmon are affected by ocean acidification, as well as the importance of salmon to ecosystems, people, and the economy
Salmon and other fish species feel the impact of ocean acidification. As acidity levels rise in the ocean, chemical imbalances are created within their bodies, which are normally balanced with the pH of the surrounding water. This can affect salmon’s behavior and abilities. Here are some of the ways ocean acidification negatively affects salmon.
Ocean Acidification Affects Salmon’s Ability to Sense Danger
Salmon are known for their extreme sense of smell, which is essential for them to search for food and avoid predators. However, when ocean acidification rises, salmon’s ability to smell is altered. According to a 2018 study, salmon that have been exposed to acidified seawater stop showing a response to the scent that tells them there’s danger nearby.
In the study, researchers created three separate salmon tanks, each with a different level of seawater acidity. After two weeks of exposure to the water, salmon in the tank with the lowest acidity levels exhibited normal reactions when the “danger scent” was put into the water. In fact, most of the time, the low-acidity salmon entirely avoided the section of the tank where the scent was coming from. On the other hand, salmon in the tank with the highest acidity levels did not respond to the “danger scent” at all, and made no attempts to avoid it.
The study reveals that ocean acidification can negatively affect salmon’s ability to sense danger. This may result in an increased mortality rate and population decrease in salmon exposed to ocean acidification.
Watch how acidic water affects salmon’s sense of smell in this demonstration from the University of Washington:
Ocean Acidification Affects Salmon’s Ability to Navigate Home
Salmon are anadromous, which means that as they mature, they migrate from the ocean to their natural spawning grounds in rivers to lay eggs. They use their extreme sense of smell to navigate the seas and rivers. This phenomenon is essential for salmon to reproduce and thrive. Unfortunately, the effects of ocean acidification on their sense of smell alter their ability to navigate home. This could prevent them from reproducing and spawning, which could also contribute to declines in their population.
Ocean Acidification Reduces Salmon’s Food Sources
In the wild, salmon mainly feed on crabs, krill, and shrimps. the negative effects of ocean acidification may impact the populations of shell-forming organisms, including many species that salmon commonly rely on for food. This could lessen the availability of salmon’s food sources, which could lead to starvation, or changing their diet. This might result in a decline in the essential nutrients salmon get from their original diet to sustain their characteristic pink features and health. In the long run, this may raise their mortality rate, reducing their population.
The Importance of Salmon
Salmon play an important role in maintaining healthy ocean and river ecosystems. They also provide benefits for marine wildlife, terrestrial wildlife, and people. However, the increasing threat of ocean acidification puts the important services that salmon provide at risk. Here are some of the ways salmon are important to ecosystems, wildlife, and people.
The Importance of Salmon to Ecosystems and Wildlife
Natural Nutrient Transporter
Since salmon are anadromous, they contribute to the transportation of nutrients from the ocean to rivers and streams. For example, in Alaska, approximately 170 tons of phosphorus are transported from the oceans to Lake Illiamna annually due to the migration of sockeye salmon. Aside from phosphorus, salmon also provide nitrogen to rivers, streams, and lakes. After they lay eggs, salmon die and release nitrogen into the waters. Phosphorus and nitrogen are essential to the growth of microorganisms and vegetation, and provide necessary nutrients to wildlife that inhabit the lake.
Food Source for Wildlife
Salmon serves as food for various types of marine and terrestrial animals. Here are some of the species that rely on salmon as their source of food:
Brown bears rely on a salmon diet for the rich calories it provides. Salmon are essential for bears, as bears need to consume around 5,000 to 20,000 calories per day, depending on the season.
Sharks, seals, and orcas consume salmon in the ocean. Salmon provides nutrients that are essential for their growth.
Bald eagles and other predatory birds that live on riversides feed on salmon when the fish return to their spawning grounds in shallow rivers and streams.
Alaskan brown bear catching salmon in Brooks Falls Source: Gary Lackie/Flickr
The consequences of ocean acidification may have an impact on the availability of salmon in areas where animals and plants rely on them for nutrients and food. If the ocean continues to acidify, it will not only harm salmon, but will also have a detrimental domino effect on the ecosystem and other species that rely on the fish.
The Importance of Salmon to People and the Economy
How Salmon Benefit the Aquaculture Industry
Industrialized salmon farming started in the 1980s in Norway and quickly grew into a global industry. Today, salmon aquaculture is one of the fastest growing methods of food production today, and makes up about 70% of the global market. Salmon have a huge impact on the global economy, so the effects of ocean acidification on salmon could be quite disruptive.
How Salmon Benefit People’s Livelihoods
In 2018, almost 60 million people relied on the aquaculture industry for their source of income. Because salmon is the most-produced fish in the global aquaculture industry, it provides millions of people with employment and income.
Health Benefits of Eating Salmon
In the 1980s, salmon was considered a fancy dish in some countries, but as the industry grew salmon became more widely available, and the health benefits and nutrients it provides to humans spread to practically every corner of the globe. Here are some examples of the health benefits of salmon:
Salmon is a good source of protein, which is essential to building muscle mass and growth.
Salmon is rich in vitamin b12 and iron, which are essential to the formation of red blood cells. This can prevent blood-related conditions like anemia.
Salmon contains potassium, which is essential in maintaining healthy muscle condition and nerve function.
Salmon also contains vitamin D, which boosts immune systems.
Salmon contains high omega 3 fatty acids. This is great for maintaining a healthy heart and reducing the chance of getting several diseases such as heart attacks, cancer, dementia, and Alzheimer’s.
The issues salmon face from ocean acidification are exacerbated by the negative pressures humans have placed on salmon populations. This includes urbanization, pollution, and dam constructions. If worsening ocean acidification is added to these pressures, salmon may not be able to continue to adapt to declining environmental conditions, and their populations will suffer.
Salmon provide a variety of services and health benefits to people, the economy, wildlife, and ecosystems, but they are threatened by ocean acidification. Ocean acidification jeopardizes the benefits we get from salmon and it may also create an ecological imbalance that could lead to other species’ extinction.
