Is The Ocean's Health Declining?

Is the ocean's health declining and how are we affected locally? Several conservation and research agencies have issued reports documenting the degradation of the world's oceans. Today we look at contributing factors such as water pollution, climate change, over fishing and dead zones.

GUESTS

"When it comes to our vision of the ocean, our vision of land in the future, it's going to look differently than our parents and our grandparents saw. And the future is one in which humans are part of the ecosystem."

• Dr. Stuart Sandin, Assistant Professor, Scripps Institution of Oceanography

"Essentially what happens on land doesn't stay on land. Pollution travels through our storm drain systems and does not get treated and is discharged untreated into our coastal waters"

• Jen Kovecses, Staff Scientist, San Diego Coastkeeper

Read Transcript

CAVANAUGH: This is KPBS Midday Edition. I'm Maureen Cavanaugh. As San Diegans enjoy beautiful summer beach weather this week, we're doing a series of interviews on the health of the ocean environment. Yet, spoke with Scripps researchers who just found that plastic from the great Pacific garbage patch is ending up in the stomachs of fish. Today we get an over view of what scientists say is threatening the world's oceans. I'd like to welcome my guests, doctor Stewart Sandin is assistant professor with Scripps institution of oceanography. Doctor Sandin, hello.

SANDIN: Hi there.

CAVANAUGH: And Jen Kovecses is staff scientist at the San Diego -- with San Diego coast keeper. Hi gen.

COONS: Hi.

CAVANAUGH: Tell us about the study you did on the decline of large ocean predators. What did you find and what does it tell us about the over all health of ocean?

SANDIN: We were looking at the fins of large animals, big consumers, and it was a group of scientists working both in the ocean and on land. What we found was that there's a common pattern across all ecosystem that people have an impact disproportionately on these big animals. By removing the big animals, we're finding really profound changes occurring to the ecosystem. There are some things you upon and. When the predators are removed, some of the prey species become more and more abundant. But other things were a little less expected. The ways that nutrients flow through the ecosystem. The nutrients are the fertilizer, say, for the trees. We were finding that those flow patterns are changing in response to the removal of the big animals. The big animals are serving ecological roles that are varied but really, really important. And what we're finding is this common pattern across ecosystems of these big removals with a number of sequences that are changing the way that humans now interact with our ecosystem. In the ocean, some of the biggest animals we're losing are the big predators, the sharks, the big groupers, the big fish in general. And those big fish are the targets for fisheries. And people enjoy eating those big animals. But when they're gone, there are other species that they interact with. And those interactions are changing the flow of energy now through fisheries. We're finding that there are some big sequences of removing those predators in terms of how fisheries are performing. And there may even be consequences where fisheries aren't as productive as they could have been because the predators are gone.

CAVANAUGH: That's fascinating. And it's just another example of how things are out of balance when it comes to the oceans. And that balance that nature had has been disrupted in a way. And we're just finding what those impacts are right now. I'm wondering, doctor Sandin, we've heard so much about changes in the ocean, I wonder if you could help us break some of these topics down a bit. We've heard about dead zones in the ocean. What are they?

SANDIN: Dead zones are areas where the chemistry of the ocean has changed. The major chemical property there is oxygen. We're getting areas of the ocean where there's not enough oxygen being produced. Remember our basic biology is the plants are creating the oxygen, and the animal vs that breathe that oxygen. If we change the environment, especially if we reremove the way energy is getting into fish or other types of animals, we can get to a condition where no longer the plants are active, and we're finding that the sing cell bacteria that infect us, they become super productive in the ocean. And the bacteria breathe like we do. They breathe oxygen. If there are too many bacteria, they use up the oxygen, and leave it as an almost no oxygen area, and now imagine being a fish through that area. You're not going to be very happy if you have nothing to breathe.

CAVANAUGH: No. And then there's of course what we hear about is the problems linked to climate change in the ocean. Can you tell us a few of those problems?

SANDIN: Yeah, so that's the third of the big impacts. We can break them down to pollution, over fishing, things that cause these dead zones. And finally climate change, the biggest global problem we have. Climate change gets a lot more dynamic in the ocean. The Oceanside is our biggest buffer to changes in the atmosphere, in terms of carbon dioxide and oxygen concentrations. But also in terms of temperature. You imagine if you turn a pot of water on your stove, it stays hot for a while. Now we have this ocean that's getting more carbon dioxide, it's getting more temperature. On average, the ocean's getting warmer. But that's changing the circulation patterns of the ocean, it's changing the interaction with the atmosphere, and this is one of the reasons, we believe, that we're getting more complex weather patterns. Maybe even less predictable weather patterns. Now add to that the CO2, this carbon dioxide, is directly dissolving into the ocean. Imagine you're making a soda can out of the ocean. That's changing the chemistry of the ocean in a pattern called ocean acidification. Ocean acidification is that basic chemistry shift is changing the environment in which all the organisms floating in the ocean are living. And especially the things that have to billed shells made out of calcium carbonate. So it's like lime stone. If you change the chemistry, if you increase the acidity, it's harder to build shells. And some of the biggest producers of oxygen in the ocean build these little shells. And by changing the chemistry of the ocean, we're changing the basic environment in which some of the most important global organisms on the planet are living. And there are gonna be some consequences.

CAVANAUGH: We often hear as I say about these problems specifically, not together, not in an over overview of what is happening all at the same time and contributing to each other to change our ocean environment. Gen, I want to go to you because you work with San Diego coast keeper. Perhaps you could describe the type of work that you do and what you see in your work for San Diego coast keeper.

KOVECSES: Thanks, Maureen. So San Diego coast keeper is very focused on protecting water quality for the inland areas of San Diego and for our coastal areas. The work that I do is really to bring forward the best available science that is out there to inform the decisions we make for policy and potential litigation. We focus a lot on urban runoff as the primary source of contamination to our inland waters and coastal waters. Essentially what happens on land doesn't stay on land. Pollution travels through our storm drain systems and does not get treated and is discharged untreated into our coastal waters. And we know from recent research that's happened in Southern California and other parts of California that that pollution is having an effect on our coastal waters. I think most San Diegans probably best connect that issue by being sufferers or summerers and we might get sick because there's other bacteria or microbes that can make us sick. But that urban runoff also contains a host of other comes, heavy metals, legacy pollutants, pesticides that can and do accumulate in wildlife. And research has shown that we're finding in sport fish an increase or higher levels of contaminates like PCBs in Southern California and in San Diego bay. There's other research that's come out from San Diego state university that's shown that the endangered sea turtles that are living in San Diego bay also have high levels of contamination in their tissues. So that all speaks to how urban runoff is contributing to degradation in our coastal waters. It's something that has both ecological impacts of the types that doctor Sanden has described but also has economic implications for areas like San Diego that are so dependent on our coastal resources for commercial fisheries, for recreational fisheries, and environmental justice implications. Because sport fish that have high levels of contamination in them means people are probably consuming those as well.

CAVANAUGH: Doctor Sandin, a major recent report by the international project on the state of the oceans said that the world's oceans are at high risk of entering a phase of extinction of marine species unprecedented in human history. Does your research agree with that conclusion?

SANDIN: The one thing that comes up in the ocean is this word of extinction.

CAVANAUGH: Right.

SANDIN: On land, the major form of litigation that we have is the enactment or the use of the epidangered species act. We go for a single species and try to protect ecosystems with it. So there's concern in the ocean as well. There are a lot fewer documented indicates of extinction properly definedment the loss of the animal or the plant from the world. We can shift that definition slightly and talk about ecological extinction, functional extinction. In essence, the reduction of the number of those animals or plants making them effectively gone from the ecosystemses, and that's certainly true. What we're seeing is sights by sights, huge declines in the production of organisms, of particular types of organisms, and those particular types again frequently are the larger bodied organisms, are the ones through direct or indirect harvest we capture. So the capture is fisheries, and we all eat seafood. But there's a lot of problems with bicatch, which is when we put out nets and catch species we don't want to catch. Think about sea turtles getting into a net when we're looking for shrimp. Those temperatures of capture lead to the mortality, the death of these animals with no real benefit. And those are having profound consequences on a lot of the larger organisms we care about.

CAVANAUGH: It sounds like from what both of you are saying that human interventions, humans are responsible for all of these changes. But haven't these things changed radically throughout history as well?

SANDIN: It's to a degree true. Talk about the sixth major extinction, there have been big events where meet years hit the planet, and the dinosaurs go extinct. What we're seeing is a lot of species that are going extinct because people are over harvesting them. But this isn't the end all be all. You're absolutely correct. There have been times that the planet's gone through dramatic changes, and it's rebounded. We're still here, we're gonna be here in a while. The goal right now is to start to consider the parts of the ocean that we care about, the parts of the ocean that give us services we need, and manage and take interest account the things we want for the future. Bicatch is a great example. We're not catching those things because we want to sell them or eat them. They're just caught by accident. So we can develop technologies, and we are developing technologies, it avoid those captures. We're changing the atmosphere because we're using fossil fuels. Well, we have alternatives to that, and it's economic use. The real consideration doesn't necessarily come from the scientific side. It comes from the public deciding what they want the world to look like, the oceans going to look like, when their kids are older, when their grand kids are older. And then start to make decisions, pass legislation or make even personal decisions to try to think toward a future that has those animals we want, has productive fisheries, has clean water.

CAVANAUGH: Jen, if there were a major threat, what is the major threat, I guess my question is, that you see to the health of our ocean environment here in San Diego.

RIH1: I would say or restate that urban runoff remains in our opinion the major threat to coastal waters and ecosystems. The flow of pollution from our landscape into our coastal waters that is untreated is high, it's hard to -- excuse me, it's hard to manage, and requires a lot of effort to control multiple different sources of pollution. It comes from everywhere, our cars, our roads, our lawns, parking lots. That requires a major change in the way we think about how our landscape is developed. There are approaches being done now in California to help address that and to really focus how can we put the ecoback in our systems on land. And as big a change as it is, I'm of the opinion from the work that I've seen being done here in San Diego and other parts of California that it is possible. We can rethink how our cities develop and control that flow of pollution into the oceans.

CAVANAUGH: Doctor Sandin, some of the problems that you've told us about are -- are so huge and have such global impact that it sounds as if it's unmanageable. Do you feel that some of these things can be turned around if we make the right choices?

SANDIN: Absolutely. But the future is not going to look like the past. When it comes to our vision of the ocean, our vision of land in the future, it's going to look differently than our parents and our grandparents saw. And the future is one in which humans are part of the ecosystem. We can never pull ourselves out of it. So the solution isn'tize lazism. It's not making parks that separate people from the environments. That maybe is part of the puzzle, but it's not the solution. The solution is recognizing that our actions have sequences, both positive and negative. We can fish in ways that are productive and feed local communities. We can use energy in ways that don't necessarily pollute the atmosphere. These are solutions, and we've got pros and cons for the environment, crows and cons for the economics, and for society. So this is our challenge. I believe that we're living in a generation that's making huge decisions for the long-term future. And again, we're not trying to get back, in my opinion, to a globe that looked like what Christopher Columbus of exploring. Even then, the globe had changed a lot because of people. We're thinking about a future that looks different but hopefully gives the services that health and welfare -- that supports the health and welfare of humanity.

CAVANAUGH: We have to end it there. I've been speaking with doctor Stewart Sandin with the Scripps institution of oceanography and Jen covexis with San Diego coast keeper. Thank you both.

SANDIN: Thank you.

KOVECSES: Thank you.