More than 3 billion people rely on food from the ocean as their primary source of protein. Without seafood to eat, many of these people will have to move where there is food available, and they will lose that healthy, local protein source. Despite this seemingly overwhelming challenge, many people around the world researching, educating and creating policies to help people mitigate and adapt to these changes. Supporting programs like this help assure these important collaborations continue.
Shellfish farmers, whose livelihoods depend on healthy marine ecosystems, are preparing for these shifts in ocean chemistry. For example, Bill Mook of Mook Sea Farm , located in coastal Maine, grows tiny oysters in tanks for his business and other oyster farmers. This technology tells him how his oysters grow in different pH conditions, which may help these shellfish adapt to changing waters. But at the end of the day, it all comes back to taking climate action.
Our energy system has powered our economy for a couple of centuries; now we need to move away from fossil fuels as an energy source and shift towards renewable power, like wave, solar and geothermal. Governments and industries must implement these cleaner systems on a large scale. It goes beyond just putting your own solar panels on your roof, but also working for change policy at the city, state, national, and even international level.
The more people who take action and talk to our energy companies and governments, the more likely it is they will respond and start making this shift. If we act now, we can continue to enjoy healthy coral reefs, eat delicious oysters, and assure the survival of our One Ocean for generations to come.
KQED has a great video that explains how pteropods, small free-floating marine snails, are struggling to build their shells in an increasingly acidic ocean and the effects on marine food webs. Some timed spawning to afternoons, when photosynthetic activity would be higher and more carbon dioxide would be taken up in the water around the hatcheries.
By carefully monitoring the acidity of the water brought into the oyster pools, they could also add carbonate to the water as needed and then move the growing oysters to the mud flats after their shells started to form.
We see it in pteropods—tiny marine snails are an important source of food for juvenile Pacific salmon. They are growing thinner shells, and the shells malform under acidified conditions. We see it in sea urchins; in crabs.
The climatological mean distribution of pH in the global ocean surface water in February On the pH scale, 7 is neutral. In more acidic seawater, a snail called the common periwinkle Littorina littorea builds a weaker shell and avoids crab predators—but in the process, may also spend less time looking for food. Boring sponges drill into coral skeletons and scallop shells more quickly.
And the late-stage larvae of black-finned clownfish lose their ability to smell the difference between predators and non-predators, even becoming attracted to predators.
For example, the deepwater coral Lophelia pertusa shows a significant decline in its ability to maintain its calcium-carbonate skeleton during the first week of exposure to decreased pH. But after six months in acidified seawater, the coral had adjusted to the new conditions and returned to a normal growth rate. There are places scattered throughout the ocean where cool CO 2 -rich water bubbles from volcanic vents, lowering the pH in surrounding waters. Scientists study these unusual communities for clues to what an acidified ocean will look like.
Researchers working off the Italian coast compared the ability of 79 species of bottom-dwelling invertebrates to settle in areas at different distances from CO 2 vents. For most species, including worms, mollusks, and crustaceans, the closer to the vent and the more acidic the water , the fewer the number of individuals that were able to colonize or survive.
Algae and animals that need abundant calcium-carbonate, like reef-building corals, snails, barnacles, sea urchins, and coralline algae, were absent or much less abundant in acidified water, which were dominated by dense stands of sea grass and brown algae. Only one species, the polychaete worm Syllis prolifers , was more abundant in lower pH water. The effects of carbon dioxide seeps on a coral reef in Papua New Guinea were also dramatic, with large boulder corals replacing complex branching forms and, in some places, with sand, rubble and algae beds replacing corals entirely.
One challenge of studying acidification in the lab is that you can only really look at a couple species at a time. To study whole ecosystems—including the many other environmental effects beyond acidification, including warming, pollution, and overfishing—scientists need to do it in the field. Scientists from five European countries built ten mesocosms—essentially giant test tubes feet deep that hold almost 15, gallons of water—and placed them in the Swedish Gullmar Fjord.
After letting plankton and other tiny organisms drift or swim in, the researchers sealed the test tubes and decreased the pH to 7. Now they are waiting to see how the organisms will react , and whether they're able to adapt.
If this experiment, one of the first of its kind, is successful, it can be repeated in different ocean areas around the world. If the amount of carbon dioxide in the atmosphere stabilizes, eventually buffering or neutralizing will occur and pH will return to normal. This is why there are periods in the past with much higher levels of carbon dioxide but no evidence of ocean acidification: the rate of carbon dioxide increase was slower, so the ocean had time to buffer and adapt.
But this time, pH is dropping too quickly. Buffering will take thousands of years, which is way too long a period of time for the ocean organisms affected now and in the near future. So far, the signs of acidification visible to humans are few. But they will only increase as more carbon dioxide dissolves into seawater over time. What can we do to stop it? In , carbon dioxide in the atmosphere passed parts per million ppm —higher than at any time in the last one million years and maybe even 25 million years.
The "safe" level of carbon dioxide is around ppm, a milestone we passed in Without ocean absorption, atmospheric carbon dioxide would be even higher—closer to ppm. The most realistic way to lower this number—or to keep it from getting astronomically higher—would be to reduce our carbon emissions by burning less fossil fuels and finding more carbon sinks, such as regrowing mangroves , seagrass beds , and marshes, known as blue carbon.
If we did, over hundreds of thousands of years, carbon dioxide in the atmosphere and ocean would stabilize again. Even if we stopped emitting all carbon right now, ocean acidification would not end immediately.
This is because there is a lag between changing our emissions and when we start to feel the effects. It's kind of like making a short stop while driving a car: even if you slam the brakes, the car will still move for tens or hundreds of feet before coming to a halt. The same thing happens with emissions, but instead of stopping a moving vehicle, the climate will continue to change, the atmosphere will continue to warm and the ocean will continue to acidify.
Carbon dioxide typically lasts in the atmosphere for hundreds of years; in the ocean, this effect is amplified further as more acidic ocean waters mix with deep water over a cycle that also lasts hundreds of years.
It's possible that we will develop technologies that can help us reduce atmospheric carbon dioxide or the acidity of the ocean more quickly or without needing to cut carbon emissions very drastically. Because such solutions would require us to deliberately manipulate planetary systems and the biosphere whether through the atmosphere, ocean, or other natural systems , such solutions are grouped under the title "geoengineering. The main effect of increasing carbon dioxide that weighs on people's minds is the warming of the planet.
Some geoengineering proposals address this through various ways of reflecting sunlight—and thus excess heat—back into space from the atmosphere. This could be done by releasing particles into the high atmosphere , which act like tiny, reflecting mirrors, or even by putting giant reflecting mirrors in orbit!
However, this solution does nothing to remove carbon dioxide from the atmosphere, and this carbon dioxide would continue to dissolve into the ocean and cause acidification. Another idea is to remove carbon dioxide from the atmosphere by growing more of the organisms that use it up: phytoplankton. Adding iron or other fertilizers to the ocean could cause man-made phytoplankton blooms.
This phytoplankton would then absorb carbon dioxide from the atmosphere, and then, after death, sink down and trap it in the deep sea. However, it's unknown how this would affect marine food webs that depend on phytoplankton, or whether this would just cause the deep sea to become more acidic itself. Even though the ocean may seem far away from your front door, there are things you can do in your life and in your home that can help to slow ocean acidification and carbon dioxide emissions.
The best thing you can do is to try and lower how much carbon dioxide you use every day. Try to reduce your energy use at home by recycling, turning off unused lights, walking or biking short distances instead of driving, using public transportation, and supporting clean energy, such as solar, wind, and geothermal power. Even the simple act of checking your tire pressure or asking your parents to check theirs can lower gas consumption and reduce your carbon footprint.
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