Keeping An Eye On Pollock

Keeping an Eye on Pollock

Welcome to "On the Line", a NOAA Fisheries podcast.

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Host: Have you eaten a McDonald’s Filet-O-Fish sandwich lately? If you have, you’ve eaten walleye pollock from Alaska. It’s not the fanciest fish in the world, but it’s a huge fishery. It’s the biggest catch in the U.S. by far, and one of the largest in the world.

In 2011, fishermen landed almost three billion pounds of walleye pollock. That was worth $375 million dollars just at the dock. Figure in processing and distribution, and all the jobs that involves, the overall value added to the economy is many times that number.

Walleye pollock isn’t just a big fishery. It’s also one of the best-managed fisheries in the world, and what I mean by that, is that the pollock fishery has been managed sustainably for years. That’s been possible because we’ve had good data on the pollock. NOAA scientists survey pollock every year to estimate the size of the population, and with that information, managers can set sustainable catch limits.

Most pollock surveys take place in the summer, but Steve Barbeaux, one of the NOAA scientists who study pollock, he wants to know what the fish are up to in the winter. But…there’s a problem. The ocean’s pretty rough up there in the wintertime.

Steve Barbeaux: Yeah. It’s so rough. We get, you know 110 knot winds up there; plus you have the ice coming down. And it’s pretty expensive to collect this kind of data. I mean one of our surveys, you know you’re running two, three million dollars easy.

Host: But fishermen are up there in the wintertime. They run these big factory ships that can handle the weather, and while they’re up there they’re using sonar to find the fish. So Barbeaux talked with a bunch of fishermen and said, “Hey, mind if we hook a hard drive up to your sonar system and keep a running record of everything you see underwater?”

Steve Barbeaux: And, it costs about $48 a pop.

Host: The hard drives that Barbeaux hooks up to the sonar systems, they record everything the fishermen see on their fish finders, including the date and time and GPS coordinates. Basically it’s like a surveillance video of what’s going on on the sea floor wherever the fishing boats go. And Barbeaux’s got a big chunk of the fishing fleet up there outfitted with these hard drives. So what does the fish finder readout look like?

Ed Richardson: It would kind of look like a snake, let’s say a red snake in a blue background.

Host: That’s Ed Richardson of the At Sea Processor’s Association, an association of seafood companies that fish for pollock in the Bering Sea. Richardson described for me how the fishermen use the sonar image.

Ed Richardson: So you trace out what the guys would call a nice mid-water snake, but they’re trying to catch it, right. They’re trying to put it in the net. So it’s not really doing them any good that it’s under the boat because the net is about two miles behind the boat. And so now they have to start maneuvering the boat and adjusting the depth of the net such that the fish are likely to go in it, and they try to catch the fish that way.

Host: Here’s the scientist, Steve Barbeaux, again.

Steve Barbeaux: With this acoustics data, what’s happening is they have it on the entire time, so it’s not only where they fish, but it’s also when they’re not fishing. We’re still collecting data, 'cause they’re moving between fishing spots and also heading back to Dutch Harbor to deliver. So we have transects from them being on the fishing grounds all the way back to Dutch Harbor. So, unlike the traditional catch per unit effort data, which just looks at where they’re fishing, we also see where they’re not fishing. And so we get a picture of the distribution of fish in the Bering Sea based on that.

Host: So the scientists are getting all this data that they wouldn’t be able to get without the help of the fishermen. But it’s not just that they’re getting more data, they’re also getting a different kind of data. When fishery scientists do a survey, they get a snapshot of what the fish are up to at a specific place in time, but what Barbeaux is getting from the fishermen is more a moving image than a snapshot.

Steve Barbeaux: And what’s also great, unlike a survey, so a survey you go out there for a week. You survey, you get one picture, right. You get a picture of the distribution and that’s your picture for the year. And, generally we can’t afford more than one survey a year. With this fishing data, what we’ve been able to do is look at the data across the season, so we’re looking at the changes in distribution over time, which is a picture we would have never gotten. And what we can look at with that changing picture over time is how are the pollock responding to environmental variants. So how are they changing their distribution based on temperature, water temperature, ice cover, storm surges? What I started looking at that data for, is how are they responding to climate change, so how could these fish potentially change their distribution on climate change. Now that we have ten year’s worth of data now, we can start looking at that as well.

Host: I can see what the scientists are getting out of this collaboration; they’re getting all this great data for free. But fishermen aren’t exactly famous for giving up their favorite fishing spots. I asked Ed Richardson what are the fishermen getting out of this deal.

Ed Richardson: You know we think it’s very valuable for the stock assessment scientists to actually understand what’s going on out there in fishing. You know people seem to think oftentimes that a fisherman when he goes out fishing, he’s got the whole Bering Sea to fish in, and he looks all around the whole Bering Sea and he fishes here and he fishes there because the fish are always here, there, and everywhere. But they’re not really. The fish, at least in catchable concentrations, are always generally in the same place at the same time, at least the fisheries on the eastern Bering Sea shelf, the big fishbowl. There’s no secrets, no unknown areas where the fish are likely to be, no mother load of gold you’re gonna find anywhere. People have been fishing out there for 30 years for flats, for cod, for pollock, and they do it more or less the same way every year. And it’s good for the researchers to understand that.

Steve Barbeaux: They have a lot of experience on the grounds, so their interpretation of what they’re seeing has 30 years of experience behind it, and so they can say, well back in 1992 we saw the fish up on the north end and the following years we had poor recruitment. That sort of, you know, qualitative reasoning, which is kind of the first step in science, right: you need to come up with your hypotheses. And so with their experience, they’re able to give us these hypotheses that we can then test these using their data.

Host: And that’s a recipe for good science to combine the hard won on-the-water experience of fishermen with the analytical and statistical rigor of egghead scientists—no offense to my scientist colleagues here at NOAA. And, good science is the basis for sustainable management.

Ed Richardson: So when you’re thinking longer term, you’re thinking sustainability. You’re thinking that we have something here that can last if we take care of it. And if you do good science, you can figure out how you can approach the harvest in a way that actually increases the sustainable yield. So you want good science not just to have a sustainable yield, but to have a high sustainable yield.

Steve Barbeaux: We’ve built a relationship where I think they trust the science, and part of that is because we’re able to sit down and talk with them about it. And they are also good businessmen, you know. I mean they really want this to keep going on into the future.

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Host: In the media, fishery management is often portrayed as this fight between the fisherman who want to catch as much as they possibly can each year, and scientists who are being overly conservative in holding them back. But that portrayal isn’t the way it really works. In most fisheries, both the scientist and the fishermen are after the same thing, and that’s a sustainable fishery that will be productive today and into the future. That’s what they have up in Alaska with the walleye pollock fishery. That’s what we have in hundreds of other fisheries throughout the nation, and where we don’t have it yet, that’s what we’re moving toward.

Host: Thanks for listening. Join us again next time for more stories about marine life and marine science. I’m Rich Press, and you’re listening to "On the Line".

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You have been listening to NOAA Fisheries’ podcast, "On the Line". Join us next time for another first-hand look at the people and the science behind managing our nation’s fisheries. For more information, visit NOAA Fisheries at www.NOAA.gov.

"On the Line" is a production of the NOAA Fisheries Office of Communications.