Depleted and endangered fish on the brink of extinction.

There may no longer be “plenty of fish in the sea.” In fact, things are so dire that a team of international economists and ecologists have predicted that the world’s oceans will be without fish by the year 2048. That is, unless we radically change how we fish and what we eat.

Worldwatch senior researcher Brian Halweil explains what is happening to the world’s fish and what action we can take to help the situation while still eating seafood.

faircompanies: What is happening to our oceans?

Brian Halweil: Basically, we know that the world’s major fish populations are endangered from over fishing, from coastal pollution, from over eating fish. And there was a study that came out recently predicting that all the world’s major fish population, from tuna to scallops, from lobster to flounder to red snapper, are going to be over-harvested, virtually extinct, by the middle of this century.

What we have to remember is that this isn’t inevitable. This was just a prediction. Actually, I think there’s a lot of hope for the world’s oceans as we get towards this sort of dire situation. And that hope is coming from people who love seafood, from big seafood buyers like supermarket chains, and restaurants.

But, also from consumers who are learning more and more that by choosing different seafood they can have a big impact on the health of the oceans. And so, what I found recently is just by treating seafood differently, by favouring certain seafood that are not as endangered and avoiding certain seafood that are harvested very destructively and that are on the verge of collapse, that consumers and big seafood buyers all over the world can have a big influence on the health of the world’s oceans.

So over-harvesting is a major problem?

Well, we can harvest certain amount of fish from the oceans without that fish population collapsing. We know that this is sort of by definition a renewable resource. If we only harvest a certain number of fish, then there’ll be plenty of other fish available still out there alive to spawn and reproduce and make more fish.

We’ve run into problems when we harvest such a large part of the population each year that the fish can’t mate, can’t reproduce and regenerate themselves. And we’ve seen that happened for everything from the whale population when we used to hunt whales, to tuna, which are greatly depleted from what they used to be, to cod which is sort of a classic example of fish that used to be abundant in every country, and now it’s basically collapsed in all the major areas where we get it.

Have governments implemented rules to solve the problem of over harvesting?

There are certain fisheries in the world where the fishermen and the government that regulates fisheries have gotten together and said, “Listen, it’s not in our long term best interest to have this fishery collapse. Let’s make some changes.

Let’s put this area of this ocean off-limits. Let’s say that we can only harvest fish of a certain size, that we can never harvest fish during the spawning season because we know that that’s an important part of the fish’ lifecycle for having fish in the future.”

This has happened in a few areas like the lobster population off of Baja California. It’s happened in certain salmon fisheries in Alaska. It’s happened in certain sardine and anchovies fisheries in Europe, where the fishermen have gotten together, partly because they were prompted by consumers concerned about fish population collapse, and said, “Let’s fish differently. We may not get as many fish in the short term, but we know we’ll have fish available for longer. Maybe we can charge a bit more because we’re doing this better, and ultimately the quality of the fish is going to be better.” That’s what it means to fish sustainably, and that’s what it means to favour sustainable fish.

And we’re seeing all sorts of labels that show up in supermarkets, and seafood shops, indicating that this salmon was sustainably harvested, that this cod was sustainably harvested. And again, it kind of gives hope because for a very long time obviously the fishing community and governments have known that fisheries were in trouble.

And, unfortunately they weren’t able to do anything about it whether it was because of political inertia or because they really didn’t want to change.

But now, here all of a sudden are seafood consumers, seafood buyers, and they’re only interest is having fish into the future. So, that’s why I’m hopeful that they can turn the tide, that they can turn the table on what’s happening to the oceans.

Do you think people are willing to pay more?

There’s sometimes a price difference. But like with buying local food and eating seasonally it also is going to mean buying different fish. I mean, in contrast to these very elaborate seafood charts which are helpful if you have them right in front of you, I tried to come up with some sort of basic rules of thumb that are little bit more general.

If you want to imagine what sort of fish we should or should not be eating: a basic rule of thumb is: we need to be eating lower on the marine food chain. We need to be eating less of the really big fish, the tuna, the swordfish, the sharks which are eaten all around the world. And these tend to be the more popular fish, salmon, they’re the big fish that are high on the food chain and they’re the most endangered ones across the board.

If we want to eat more sustainable seafood, it’s going to mean eating the smaller fish at the bottom of the food chains. Things like clam, and oysters, molluscs, the smaller fish like anchovies and sardines which are very popular in New York, we don’t really have a tradition of eating them in this country. These fish are less endangered partly because they’re lower on the food chain, there are more of them and they reproduce faster. So that’s a pretty straightforward shift.

Should that apply for farmed fish as well?

Also, when you think of buying farmed fish, again farmed fish that are lower on the food chains. So instead of salmon or tuna, which have to be fed other fish when they’re raised on farms and ultimately don’t yield as much fish as we put in, we should be eating those fish that are lower on the food chain like carp, like tilapia, like catfish, some of these more vegetarian fish.

The fish farming has been going on for thousands of years and obviously part of this solution of increasing the seafood supply, even as wild fish are depleted. But this whole idea of raising these big carnivorous fish like salmon and tuna is a wholly new concept.

It’s very destructive, very inefficient. It’s kind of analogous to what we do with cows, packing them into these tight feedlots and feeding them very inefficient and unhealthy food. The sort of fish farming that’s gone on for thousands of years and is completely sustainable is the type of fish farming where you raise these fish that can essentially be raised on vegetables, like carp, like tilapia.

It’s a very efficient way to use waste vegetable products and you still get the same benefits in terms of the health benefits of eating the seafood.

The real irony is that just as we’re understanding what a great food fish is, how healthy it is, how it’s a brain food, it’s a heart’s food, it’s a sort of super food, at the very same time we’re realizing how depleted the ocean’s are. So, if we want to keep seafood part of our diet into out future, we really have to treat it differently, and eat a very different type of seafood and eat less seafood in the short term.

Are there any health factors to consider when choosing what fish to eat?

Yes, most definitely. If you’re concerned about mercury contamination and some of the other toxins that are beginning to accumulate in seafood, the fish that are most important to avoid are again those bigger, longer lived fish that are on top of the food chain.

Those are the fish that concentrate the most toxins just because they’re fattier and because they’re at the top of the food chain. So, tuna is not just good to avoid because of concern about mercury, but also because we’ve over fished tuna in most of the world.

At the same time eating seafood that’s lower on the food chain: anchovies, sardine, clams and oysters, is also a good bet to avoid these sorts of toxins. Those fish tend to have less fat and they don’t accumulate as much of those toxins because of what they eat. So whether you have health concerns, or you’re just concern about the fish population in general, it’s a good rule of thumb to begin eating lower on the marine food chain.

Does buying from small fishers make a difference?

One other rule of thumb to keep in mind is to: think about how the fish were caught, and it’s the situation similar to trying to support small farmers. Small fishers, go after fish in a very different way than these massive industrial trawlers.

Lots of the world’s fish is caught by these giant sort of floating factories, where they drag a huge net across the ocean floor. And part of the reason that the world’s fish population have become so endangered is because we’ve gotten so good at fishing.

We literally can pinpoint where the fish are, using all sorts of radar and sonar technology. Technology that was developed primarily for military purposes is now being used to figure out exactly what’s going on under the oceans. And once we’ve figured out where the fish are, we can go after them with a net that’s so large that it could literally pull a 747 airplane off the bottom of the ocean floor.

And this is the reason why the world’s fish have become so endangered. It’s because it’s no longer luck for fishermen. It’s always been partly luck. But now it’s entirely about can we get to the fish and can we reach them. And we can reach them at wherever they’re hiding at this point.

Now, smaller fishers are still constrained by certain sorts of seasonal and other obstacles. They’re not going after fish by dragging a net on the ocean bottom. They’re still going after fish in very selective ways like with a hook and line, with a smaller net, with all sorts of fish traps. And so another good rule of thumb if you want to avoid the most destructive or most endangered fish is to: try to buy seafood from smaller fishes, from smaller fishing boats because you know that they’re not going to be using the most destructive fishing techniques like dragging a net along the ocean bottom.

And there is also a good chance that the fish is going to be fresher because these industrial fleets go way out into the middle of the ocean, burning all sorts of fuel, and they have to store that seafood frozen for a very long time. Whereas smaller boats that aren’t going as far out often catch the fish and are back at the market by the end of the day. So, choosing fish that’s caught by smaller fishers, more artisanal fishing techniques, is also a good bet that you’re doing better for the ocean, but also that the quality of the fish is likely to be higher.

What about buying farmed fish versus buying wild fish?

Well I think whether a farmed fish or wild fish is a better choice is again going to depend very much on what fish you’re talking about. We know there are certain wild populations of fish that are less endangered, less at harm and we know that there are good and bad ways of farming fish.

So, I think you have to ask how is that fish being farmed and how that fish is being caught. It’s not accurate to say that farmed fish is better for the oceans because you’re taking pressure off of wild fish populations.

We know that a lot of fish farms not only produce fish that isn’t very healthy and raise fish in a way that uses all sorts of chemical and is very energy intensive. But, very often fish farming uses more fish than it actually produces which is surprising.

But if you’re raising salmon or tuna in giant fish pens you feed them a lot of fish, because that’s what they live on. So, if you think about shrimp farming for instance, which is very problematic, wherever it’s done they often have to feed five pounds of fish and other seafood to get one pound of shrimp. So it’s very inefficient.

And yes, maybe it’s taken pressure off the wild shrimp population but what about those five pounds of seafood that had to be caught at see to dump into the shrimp pens.

Farmed fish in general, is problematic if you’re buying these big carnivorous species. But if you’re buying fish like carp or tilapia that can be raised on vegetable matter is much more sustainable. And in fact, it does take a lot of pressure off of the oceans. Again, the most important thing to do if you have questions is to ask those questions.

The managers of seafood shops, and the chefs in restaurants should know these things. They should have answers for you and if they don’t know they’re going to find out. And just simply by asking you’re going to get them more curious about the seafood that they buy.