Why Ocean Health Is Better And Worse Than You Think

The good news is the world’s oceans have not experienced the extinctions that have occurred on land. But as ecologist Douglas McCauley explains in a Yale Environment 360 interview, marine life now face numerous threats even more serious than overfishing.

Last month, a group of marine experts — including lead author Douglas McCauley, an ecologist at the University of California, Santa Barbara — published a groundbreaking study in the journal Science that delivered a sobering message: The world’s oceans are on the verge of major change that could cause irreparable damage to marine life.

Poring through a host of records and data sets, ranging from ancient fossil records to present-day catch statistics, the scientists drew conclusions that were both heartening and disturbing: While ocean ecosystems are still largely intact, the marine world is facing unprecedented disturbances, including acidification from the absorption of greenhouse gases and widespread habitat destruction from deep-sea mining, oil and gas drilling, development, and aquaculture.

Douglas McCauley

In an interview with Yale Environment 360, McCauley discussed the parallels of “defaunation” — or loss of wildlife — on land and at sea and explained why the creation of large marine reserves and the establishment of international ocean zoning regulations will help blunt the damage from a looming “marine industrial revolution.”

Yale Environment 360: What did your study reveal about the state of the oceans today?

Douglas McCauley: Science asked us to consider the sixth mass extinction that’s been happening on land and have a look at what the case was with the oceans. So to take this on we tried to grab as much information from as many places as we could. We really had no idea what we were going to find. The most important message, and a signal that was repeated in a lot of different data, was that the sixth mass extinction is not underway in the oceans. That was the good news. The bad news is that as we looked into the way we are changing our use of the oceans, there were a lot of data suggesting that we’re in a really important transition zone and may in fact be crossing over a threshold in the state of health for [marine] wildlife. Many of these diverse points were telling us that things were healthy in the oceans, and we are ahead of the game in terms of marine wildlife conservation, but we are just about to lose that edge.

‘It is the transition from harvest to habitat degradation that has us so concerned.’

e360: This gets into an important conclusion of the study. You talk about how we seem to be on the verge of transitioning from an era in which harvesting and fishing of marine resources has been the main driver of impoverishing biological diversity to one in which massive habitat change and, as you all call it, `global chemical warfare’ [acidification] may be waged on the oceans. Can you talk about that?

McCauley: It is that transition from harvest to habitat degradation that has us so concerned. We think this is a really transitional event in ocean wildlife health. When we talk about degrading health in the oceans, it’s usually about harvest. But we ran this environmental history of what we’ve done to wildlife on land, in parallel to this review of what we are doing to wildlife in the oceans. On land what we did was we started first by simply hunting wildlife. And then we switched over to wanting the same resources and wanting the same space that these wildlife were using. This transition was most pronounced during the Industrial Revolution, when our cities were growing and we needed resources for everything that was coming out the other end of these fabrication lines. When we look at how extinction of terrestrial wildlife changes over time, you see a pretty distinct signature that things pick up right there, when we switched over to damaging wildlife habitat. It just makes intuitive sense — if you hunt individuals intensely that’s going to have negative impacts, but if you go through and actually ravage the homes of these animals, it’s going to be a lot harder to recover and the impacts are going to be more profound.

To return to the ocean, it became very clear that things were way behind in this sequence in the oceans, certainly hundreds of years behind in terms of the health of [marine] wildlife and extinction. On land, you have entire communities of organisms that have gone extinct across continents, with lots of large animals being completely driven extinct. In the oceans, we don’t see any of that. We have white sharks and baleen whales still swimming around out there. When we look at rates of marine habitat degradation, and how far off is this transition, there is no reason we have to follow the same history. But then you look at the way we are impacting coral reef cover, the way that fish farming is eating up mangrove forest, the amount of factory building that we are doing in the oceans for energy production. Seabed mining can only be described as a gold rush that’s underway under the ocean now.

‘We may be repeating the history that had such devastating consequences for wildlife on land.’

We went industry by industry, looking at the beginnings of the signals of habitat degradation, and all of these curves that we plotted were scary and were increasing incredibly rapidly. This suggests that we’re about to move into this marine industrial revolution, that we may be repeating the history that had such devastating consequences for wildlife on land.

e360: The focus in the press and what has seeped through to the general public is the hammering the oceans have taken from overfishing. But in essence you’re saying that we can recover from that, but we’re not going to be able to recover from this major impingement on marine habitat that we seem to be on the verge of right now.

McCauley: You’ve hit on a message that I would like to accentuate. Overfishing is a major problem that is having extremely serious impacts on the oceans. We haven’t caused that many species to go completely extinct as a result of overfishing — in the last 500 years we’ve caused 15 marine animal extinctions, and on land 500 animal extinctions — but we’ve certainly depressed numbers. There’s no longer plenty of fish in the sea. But what we’re saying is look down the pipeline and there is something bigger and worse coming that already hit our terrestrial ecosystems with devastating consequences. So let’s keep our eyes on this emerging rising tide of industrialization in the oceans.

Why are we beginning to industrialize the oceans? Why all this interest in sea floor mining? The obvious answer is that there are just so many more of us on the planet that have so much higher energy and resource needs, and that we have to start reaching into the oceans for things that we require in our everyday lives. But, we can do this the intelligent way or the dumb way, and when we did this during the Industrial Revolution on land we did it probably the worst way possible, with just zero insight for the environmental impacts, and we’re still cleaning up the mess of this run-wild industrialization that happened during that period, when there was no social consciousness.

‘We need to be smarter about how to industrialize the oceans and put industry in the right places.’

But we’re in a totally different place in 2015. We know that of course it’s bad to lose species simply because they are part of the richness of life on our planet, but we also know that losing a species is bad for the health of society. So we know that we don’t want to make the same mistakes. What we can do, if we still need those minerals, if we still need the energy, is just be smarter about how to industrialize the oceans. But we need to put industry in the right places. If we need to develop a section of the oceans that turns out to have really bad impacts for wildlife, we need to do remediation somewhere else. So it’s all about zoning and putting in this development with careful forethought about what it does to habitat and to wildlife that depend on that habitat.

e360: I was a little surprised at the emphasis that the paper put on undersea mining. Could you say a few words about this threat? Were you and your colleagues surprised at the extent of the proposed mining of the sea bed?

McCauley: I certainly was. I just didn’t realize the scope of the developments being proposed by the mining industry. It’s good to emphasize that these are very early days for marine mining and so scientists and ecologists don’t yet know what it’s going to do to the oceans, and the industry itself doesn’t know where they are going to run with this. But there are millions and millions of dollars that are being invested to build technological capacity to mine minerals, and they are talking about doing this in the deepest parts of the oceans. So it’s a hard problem and we know very little about it. And the numbers involved are a bit scary — a million square kilometers that have been staked out in this marine gold rush. We haven’t set machines to work on the sea floor yet, but that’s going to happen in the next couple of years, with some of these first projects in the Pacific.

There’s an incredible amount of uncertainty in the science community about what impacts it’s going to have. So I think it’s an industry definitely to watch closely when you are talking about so much of the sea floor that is going to be impacted. This is probably going to be our first, our hardest, and our most important test case for ways to zone this emerging marine industrial revolution. We’re not talking about putting down a sub with an arm that plucks off a small rock. This is like taking mountaintop removal [coal mining] and putting it underwater. There are 300- ton machines that are coming off the factory line in the U.K. to be able to do this.

e360: Let me ask you about another threat, what you call global chemical warfare. How worrisome is ocean acidification from absorption of the CO2 that we are putting into the atmosphere?

McCauley: It has to be right up at the top of the list. There are two major changes that are happening in the oceans as a result of climate change — changing temperature and acidification. If you take a tank of tropical fish and you turn the temperature up in the tank and you drop some acid in that water, it’s obvious the fish aren’t going to fare well. And that’s what we are doing to the oceans, slowly but surely. Addressing other issues like overfishing or this explosion of sea floor mining are going to be really important, but if we’re cranking up the temperature controls or acidifying all of the oceans then our progress on these other fronts could well be muted. We need to keep climate change and climate change effects on the oceans — and what this means for wildlife — at the top of our agenda.

There is some encouraging news. We actually see the beginning of how these ocean animals are starting to cope with changes in temperature and ocean acidity, and we see some capacity for adaptation. One study looked at corals in variable environments and it looks like some of these corals are beginning to show the capacity for resiliency to cope with some of these temperature increases, in particular, and continue to make a living. So what we need to do is basically slow down the rate of the advance of climate change. Any time we can buy for the rate that temperature and acidity go up is going to buy more time for ocean animals to adapt. It’s possible they can adapt if the process doesn’t go at such incredibly high rates that it totally swamps their physiology and knocks them out immediately.

e360: You make it clear in the paper that there’s still time to help prevent mass extinctions and even much deeper damage in the oceans. Can you outline the top priorities in terms of solutions?

McCauley: I think the first thing is to emphasize is that what we are seeing here is actually quite rare. Quite often our science shows that it’s already too late or the disaster itself is well upon us. But this is different. Things are badly damaged in the oceans, but because we don’t have mass extinctions in the seas as we have had on land, the raw ingredients are still out there. We haven’t driven the last of these animals extinct, so we have the building blocks to remake some of these marine communities. We are catching this early so we can actually intervene in ways that we didn’t in other major environmental catastrophes that we faced.

‘Slowing marine defaunation is triply hard because large parts of the oceans have no owners.’

As for big things we can do, first, we need more parks and protected areas in the ocean. It’s something that we need to very actively tell our policy makers to do. In the past year, Obama set aside one of the largest marine protected areas in the world, in the Pacific, and that was a wonderful thing for wildlife. But what was a bit disheartening was that his original plan was actually to protect about twice the amount of area that he ultimately set aside. He backed down a bit simply because there weren’t enough voices saying, `These parks are something we absolutely need for the environment.’

e360: And what about thorny issues like zoning the ocean for undersea mining? Given that a lot of the ocean lies outside the 200-mile exclusive economic zones (EEZ) that surround all countries, how is the global community going to get a handle on zoning the commons of the ocean, the part that doesn’t belong to individual nations?

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McCauley: That’s going to be critically important. The vast part of the ocean is outside of the EEZs of countries. We made a mess of things for wildlife on land and land is all assigned to a country, so it’s very clear who is the steward. But the processes of engaging and slowing marine defaunation is made triply hard because large parts of the oceans have no owners. But there is a growing awareness that we need to build international alliances to think about marine wildlife issues. With whaling, we all got together and said, `We are going to lose these mammoths of the sea.’ So with collective decisions across countries, we largely stopped international whaling.

We can do the same thing on a species-by-species basis — next up is going to be tackling tunas, and sharks aren’t far behind. So we’ll have to have species-specific international alliances, but more broadly we will need to think more carefully about what we are going to do in this international space. I think we can look to some of the models that we are using for combating climate change, because, again, we are talking about a global issue that goes beyond borders. We should be having the same kinds of high-profile meetings about what’s happening to the health of wildlife on the high seas. One of the things we talk about in the paper is the mobility of marine life. Marine animals will on average move much farther than terrestrial animals — bluefin tuna, whales, and dolphins use entire oceans and could care less about our EEZs. Because so many of those larger animals are on our endangered species list, the only way to keep them from going off the extinction cliff is to negotiate those international agreements.