News, opinions, photos and facts from Ocean Conservancy
About Sarah Cooley
Sarah Cooley, Ph.D. joined Ocean Conservancy as a Science Outreach Manager in the Ocean Acidification program in January. Previously, she was a research scientist at Woods Hole Oceanographic Institution in Woods Hole, Massachusetts.
Let’s take a moment on Mother’s Day to remember the ocean. Like mothers everywhere, the ocean looks out for us in the most basic ways. It’s easy to take those things for granted. Thanks, Mother Ocean, because you:
Gave us life. Earth scientists believe that the first life on Earth arose in the ocean, which brought together chemicals in a rich “soup” that gave rise to primitive cells. These early life forms evolved and diversified into the myriad organisms that exist today.
Keep us warm. The ocean stores a tremendous amount of heat that regulates the planet’s overall temperature. Ocean currents redistribute heat around the Earth to keep temperatures relatively stable. Not too hot and not too cold, the Earth’s small overall temperature range is critical for our survival.
Photo: Flickr Creative Commons, flippy whale, sai kung
How do you like to make big, complicated decisions? I like to write lists of pros and cons associated with the choice I’m leaning towards. That’s served me well for changing jobs, selling houses and more.
But for complex systems, like fisheries, simply comparing pros and cons of one choice isn’t enough. There are many moving parts in a fishery, and they are interconnected. For example, when fishermen harvest sea scallops, they reduce the overall number of scallops in an area, and change the age and size distribution of individual scallops. At the same time, factors like rising water temperature, availability of food, or quality of habitat can also affect scallop populations, and external factors like the price of scallops or gasoline can influence the intensity of fishing effort. So, changes in a fishery often lead to outcomes that don’t necessarily generate neat bullets you can compare on a balance sheet.
It’s especially challenging to plan for both short and long term changes in a fishery. Most fisheries are managed to accommodate short-term changes that last a few years, like natural fluctuations in population size. But fisheries management today generally doesn’t also consider long-term changes spanning many decades, like warming and ocean acidification, even though we know those changes are gradually tilting the playing field for many marine species.
When studying major global changes like warming, ocean acidification, or ocean oxygen loss, scientists often look back in the geological record to see what happened when Earth experienced similar conditions before. That helps scientists put global change in the proper perspective.
In past geological ages when volcanic activity has been high, atmospheric carbon dioxide levels have risen and dramatically changed the Earth’s climate and ocean chemistry. Last week’s Science study focuses on one of these periods—the Permo-Triassic (P-T) boundary. It’s one of the most “rapid” releases of volcanic carbon dioxide to the atmosphere, taking 60,000 years. As slow as that seems, it’s fast for the Earth—60,000 years out of a 4.5 billion year old planet’s life is like half a day of a 100-year-old person’s life. All this volcanic carbon dioxide drove rapid ocean acidification towards the end of the P-T boundary, and a major extinction of ocean life followed. Marine life with calcified shells and skeletons, like corals, shellfish and calcifying algae, were pretty much wiped out.
Three years ago, I teamed up with an economist, a human geographer, and another ocean acidification scientist to lead a study that would identify ocean acidification “hotspots” around the United States – places where ocean changes will be large and coastal communities depend heavily on shellfish harvests, but where people don’t have many resources to guard against losses of these harvests. We gathered a group of 20 science and policy experts to study the issue at the National Science Foundation-funded National Socio-Environmental Synthesis Center (SESYNC). Since then, we’ve synthesized information about the oceanography, shellfish harvests, and coastal communities across the United States in a formal risk assessment. We’ve just published our results in Nature Climate Change this week.
Pink shrimp raised in tanks that simulate the more acidic ocean expected in the future just don’t taste right, according to a recently published research paper from Sweden. For the first time, a scientific study has looked at the effects of future ocean conditions on the taste of seafood.
Teaming up with a professional chef, the researchers cooked and served local shrimp that had been raised for three weeks in high carbon dioxide conditions alongside shrimp raised in regular conditions. Volunteer taste testers then tried both kinds of shrimp and scored them on appearance, texture, and taste.
Ocean acidification didn’t affect texture at all, but it significantly hurt the shrimps’ appearance and taste scores. Shrimp raised under regular conditions were more than three times as likely to be rated the best shrimp on the plate, and the shrimp raised with high carbon dioxide levels were about three times as likely to be rated the worst on the plate.
It’s been a depressing few weeks in ocean news. I’ve seen lots of downer headlines lately about new studies saying we’ve “screwed the oceans” with carbon dioxide pollution, left a dirty “bathtub ring of oil” in the Gulf of Mexico, and dumped so much plastic in the ocean that whales are choking to death. Plus I can’t escape the bickering in every media outlet about whether or not the carbon emissions agreement between U.S. and China means anything. You’re probably exhausted by it all too. But before you totally tune out, thinking that the ocean’s problems are just TOO big, let me tell you why I haven’t given up on the ocean.
As you know, I’m a scientist, so I like to think first about how science will help us out of this fix. My colleagues and I have been working on ways to break down what puts individual communities at risk for ocean acidification. We did this recently for Alaska, and now we’re finishing a similar study for the whole United States. Turns out, it’s not just oceanography that puts human communities at risk – it’s also the ways humans depend on marine harvests, and the ways communities are put together socially. This is great news for community leaders, who can encourage future regional development that will decrease these risks. The scientists who reported on the Gulf’s oily bathtub ring also point out that their research sheds light on how oil moves and breaks down in deep water, which offers ways to “avoid and mitigate oil spills in the future.” This is great news for accident response planners and restoration experts. And finally, studies of how marine animals eat plastic debris does shed light on how these animals hunt and behave (a tiny silver lining in a very, very, dark cloud), but most importantly, these studies have grabbed everyone’s attention. People around the world are appalled by this. And as a result, there is a growing movement to address ocean trash that is co-led by plastics manufacturers.
“Ocean acidification is a pocketbook issue here. It’s about dollars and cents and jobs,” said New Bedford Mayor Jon Mitchell in Massachusetts at Monday’s conference on Ocean Acidification and Southern New England. Organized by the Woods Hole Research Center, this workshop brought together fishermen, planners, ocean acidification experts, and policymakers to jumpstart action on ocean acidification. Mayor Mitchell noted, “There is no more appropriate place to discuss ocean acidification” than in New Bedford, where smart fisheries management has led to a scallop boom. In fact, the city is the sea scallop harvest capital of the U.S. and its port consistently brings in the highest commercial fishery revenue in the country each year.
The workshop began reviewing the science of ocean acidification as it relates to Massachusetts’ oceanography and fisheries. There’s still a lot to learn, particularly about how iconic fisheries like sea scallops and lobster respond to ocean acidification. But it’s clear that there is a lot to be worried about in New England. Seawater acidity is greater in these waters today than it was 35 years ago.