Think Out Loud

New research suggests ways to reduce bycatch in commercial fisheries

By Sheraz Sadiq (OPB)
Jan. 26, 2022 2 p.m.

Broadcast: Wednesday, Jan. 26

Boats park at a dock.

Midwater Trawlers Cooperative has nearly 30 fishing vessels, including these three trawlers docked at the Port of Newport that fish for Pacific whiting off the coast of Oregon.

Heather Mann/Midwater Trawlers Cooperative


Commercial fisheries have strict limits on the amount of fish they can catch. And often they also have to abide by limits on bycatch of marine animals that get unintentionally caught on fishing lines or nets. A new study from the University of Washington suggests that when it comes to reducing bycatch in the fishing industry, permanently closing off stretches of marine areas may be less effective than dynamic, temporary closures. Ray Hilborn, a marine biologist from the University of Washington’s School of Aquatic and Fishery Sciences, joins us, along with Heather Mann. She’s the executive director of Midwater Trawlers Cooperative, a nonprofit trade association of nearly 30 fishing vessels based in Newport.

The following transcript was created by a computer and edited by a volunteer:

Dave Miller: From the Gert Boyle Studio at OPB. This is Think Out Loud. I’m Dave Miller. According to the National Oceanic and Atmospheric Administration, the US has established more than 1,000 Marine Protected Areas in oceans, estuaries, coastal waters and Great Lakes. This is part of a growing movement around the world to close off sensitive marine ecosystems from fishing. One of the reasons for these protected areas is to reduce by-catch, meaning the accidental take of marine animals as opposed to those that  are the target of commercial fishing. But a new study from the University of Washington suggests that when it comes to reducing by-catch, permanently closing off stretches of marine areas may be less effective than temporary and dynamic closures. Ray Hilborn was the Lead Author of the study. He is a Marine Biologist from the University of Washington, School of Aquatic and Fishery Sciences. He joins us now along with Heather Mann, she is the Executive Director of the Midwater Trawlers Cooperative, that’s a nonprofit trade association of nearly 30 fishing vessels based in Newport. Ray Hilborn and Heather Mann, Welcome to Think Out Loud.

Ray Hilborn: Oh, hello.

Miller:  Ray Hilborn, first. Can you give us a sense for how serious an issue by-catch is in various fisheries around the world?

Hilborn:  Oh, it’s a very serious issue in a lot of fisheries, it’s probably the major threat to a number of sea birds and some marine mammals and marine turtles. Those are the ones that tend to attract the most attention, but it’s also a problem of by-catch of Salmon in the Alaska Pollock Fishery. Almost everywhere you go by-catch is a problem for everyone. The fishermen don’t want to catch them, but you can’t put your net or your hook in the water, typically, without catching some things that you don’t target.

Miller: Heather Mann, what species of fish or birds or other marine animals typically show up as by-catch for the fishing vessels that are a part of your fishing cooperative. What are the ones you worry the most about?

Heather Mann: Dave, I would say that for the Pacific Whiting fishery off the west coast, we’re doing our best to avoid Chinook salmon as incidental catch. And then lately with changes in ocean conditions and feed moving around and temperature changes. A Short Belly Rockfish is a species which has just exploded in population. And that’s something that we tend to run into in the last couple of years when we’re targeting Whiting.

Miller: So for the Chinook, the first example you mentioned, what happens if some number of Chinook are caught along with the Whiting?

Mann: Well, what happens is that there’s a hard cap for the amount of Chinook that can be caught in the Whiting fishery each year. That number is 11,000 individual Chinook. And if that number were to be exceeded, even if there were still quite a bit of Whiting left in the water that hadn’t been harvested yet, that fishery would close.

Miller: Oh, so I mean, and that is a gigantic economic disincentive for catching too many Chinook, meaning you would have to stop even if technically there were more fish that you could take for your quota, but if you took too many Chinook, you can’t get any more Whiting?

Mann: That’s correct. And that would be a huge economic hit to coastal communities. Whiting is the largest fishery by volume on the west coast. And so that’s why we take extraordinary measures to do everything we can to avoid incidental catch of Chinook.

Miller: With 11,001 and it’s shut down. So that means every single Chinook is counted?

Mann: That’s correct. In the whiting fishery, our vessels are 100% accountable, meaning they’re observed 100% of the time at sea as well as at the dock. All Chinook that are encountered are retained and delivered. You’re not paid for that Chinook, but the Chinook is delivered. Sometimes genetic samples are taken to determine which river they originated from. And then that fish makes its way into Food Banks and Meal Programs in Oregon.

Miller: So Ray Hilborn, this is just one example of one fishery and one fish that could be caught inadvertently. What was the goal of your study with respect to by-catch?

Hilborn: Well, the overall goal of the study was to understand how effective area closures and also temporal closures are to reduce by-catch. Taking into account the issue that if you go out and you close an area because that’s a place you see it’s a lot of shark by-catch. What happens is the boats fish somewhere else and typically catch more of something else. So that’s the big dilemma is that the Marine Protected Areas are not reducing fishing effort there simply moving it. And the question is, how effective is that tool at reducing by-catch.

Miller: Was the idea of Marine Protected Areas and I mean my understanding is that they have multiple goals, but to the extent that one of those goals is about reducing by-catch, what have they been put in places where marine scientists figured for example that there there are a lot of shark there and the shark are getting caught. So let’s say nobody can fish for something else here because the sharks are getting… I mean, were they chosen with by-catch in mind?

Hilborn: Well, basically, yes, but somewhat indirectly, they’re often cited in places where species of concern are commonly found. But those tend to overlap with places where there’s a lot of by-catch.


Miller: Hmm.What fisheries did you study in the US or around the world as a part of this analysis?

Hilborn: Well, we relied on 15 different fisheries. In the U. S., the Alaska Pollock fishery was one. The Eastern Pacific Tuna Fishery was another. God I’d have to look on the map. But there were a number of American fisheries and there were a number of fisheries from Latin America and other places.

Miller: And what did you find, broadly?

Hilborn: Well what we found is that permanently closing areas is a relatively ineffective method for two reasons. Probably most importantly the distribution of the species shifts from year to year, so that it’s not that places are reliable hot spots of by-catch. But the other problem is that you do… you protect an area, you close an area because you tend to catch a lot of one species there, and at almost every one of the fisheries we looked at, there were many species of by-catch concern and you simply move the effort where you get more by-catch of another species. And because one of the things we know that what climate change is doing is moving the distribution of fish and that’s why we weren’t too surprised to find that if you can move the closed areas, they’re much more effective than if they are permanently in place, because you move them as the distribution of the fish changes.

Miller: That’s an interesting point here. In other words, climate change, which as we’ve heard many times, it could really to a greater extent, even be called ocean change since oceans are absorbing so much more of the heat than land is, that if that’s making oceans even more dynamic than ever and changing them so quickly, then static lines that sort of invisibly, artificially go down to the ocean floor, they’re less likely to be effective. Heather Mann, where are the commercial fishermen that are part of your cooperative seeing the effects of climate change in terms of what they’re picking up inadvertently?

Mann: Well, as I mentioned before, Dave, I think that Short Valley Rockfish is a really good example of a species that is out there in huge numbers that we have not seen, both in numbers and areas before. And so that population has grown. It was mainly a Southern California spot that you would be seeing them. And so now we’re running into Short Belly Rockfish off of Oregon and even Washington and again, in numbers we have not seen before. So that’s an example of fish moving due to changes in ocean conditions in the climate.

Miller: Is that a potential commercial fishery?

Mann: It is not, and that is part of the problem. The volume is there, the fish itself is not something that is useful for food consumption. It’s very small. It’s been described as having a filet, the size of a potato chip. No, it’s not something that really lends itself to a food fish that we would want to be marketing. And when we’re fishing for Whiting, that’s our target species. And if we’re catching Short Belly it makes the trip less efficient – if you’re moving, if you’re catching that fish, you have to deliver it because you have to bring in everything that you catch as part of the accountability component of the fishery. And the processor isn’t wanting that fish, you don’t get paid for it and you’re wasting time, energy, fuel, carbon footprint, delivering Short Belly Rockfish when you really want to be delivering Hake or Pacific Whiting, which you’re going to be paid for.

Miller: So Ray Hilborn, I feel like I have a pretty good sense for how a Marine Protected area would work. There’s just, there’s a map with a, there’s a box, and once you go inside that box on the map of the ocean, you can’t fish there. Maybe I’m… I’ve oversimplified it, but it seems like that’s the basics of it. But how would a dynamic closure work?

Hilborn: Well, first, let me say dynamic closures are quite commonly used now in Alaska and both the West Coast and they work, the way they mostly have been implemented is by tracking where by-catch is occurring and when you have a hot spot of by-catch, like let’s say in the Pollock, I mean in the Hake fishery getting, finding a lot of Salmon are being caught in this area, that area is closed. It’s mostly been done in the US West Coast as an industry initiative because they face these hard caps. And so they have contracted individuals to get the data, identify where the hotspots are, and then the fleets have, in the form of cooperatives, have signed legally binding agreements to agree that when this person, this contract, it says this area is closed, they have to go fish somewhere else. So that’s the other way it would work is where by-catch is typically associated with dynamic ocean features like ocean fronts or certain temperatures or something. And then you monitor those places and close them based on oceanography without collecting real time by-catch information. But you have enough historical data to show you that that’s where the by-catch would occur.

Miller: So Heather Mann, I’m curious what stands out to you in this new study from the commercial fisherman’s perspective, what do you make of the idea that the policy suggestion that’s embedded in the results of this research – that dynamic closures would be better not just for by-catch, but for commercial fisheries than hard and fast ones?

Mann: Absolutely. I agree with the premise. This is something that we’ve been advocating for a long time and we’re actually using it in practice. If you think about your previous guests and sort of talking about the bureaucratic red tape that exists, it’s no different in federal fisheries management and management has a really difficult time keeping up with what’s happening in real time on the ocean.  So in the Whiting fishery, we operate in co-ops where we’re sharing information on a daily basis about what’s being caught in every single tow** , where it’s caught and what else is being caught with that Whiting and if we have a high incidence of Chinook that is known immediately, the lat [latitude] and long [longitude] and where it was, how many Chinook came up in the tow**, and then depending on the rules within the co-op, you may be required to move to another area. And so we have voluntary areas that are closed off. Those change in real time throughout the fishing season based on input from skippers on the grounds, as well as the information that’s coming from the fish tickets, that’s what’s recording everything that we’re bringing in, and the success of these, for example, efforts are that in 2020, the Whiting sector caught over 633 million pounds of Whiting. During that same season, we only interacted with 2,400 individual Chinook and that’s really essentially less than one Chinook for every, you know, quarter of a million pounds of Whiting. So these kinds of dynamic closures, combined with things like no night fishing during certain times of the year requiring test tows, using gear that has Salmon excluders, all these things together are what I consider dynamic closures or dynamic types of efforts to reduce and mitigate your interaction with species you don’t want to be catching.

Miller: You mentioned an important other tool there, which is connected to, but also in its own way separate from closures, which is the actual equipment itself. Ray Hilborn, my understanding is that this most recent study, you didn’t look into equipment used to prevent by-catch. It was instead, it was about how closures could be most effective. But can you give us a sense globally for the kinds of technological changes that are being employed to maximize getting the fish or crabs or whatever, the target and minimize getting the animals that are not the target?

Hilborn: Yes. And some other work that isn’t, isn’t yet published, we’re showing that these kinds of gear changes are just far more effective that in some cases they’ve reduced by-catch by 99%. and that closures where…I mean dynamic, as Heather said, they employ a mixture of dynamic closures and gear changes and they’re being very successful at that. But the real secret is finding ways to modify the gear to dramatically eliminate and  reduce by-catch. But dynamic closures certainly have a role to play.

But the key point is that if you want to protect biodiversity from fishing impacts, the dominant way it’s affected is by unwanted catch and by-catch particularly for endangered species and permanent closed areas which are sort of being touted as the silver bullet, and it is proposed that 30% of the oceans be closed to fishing. It’s just not going to do a very good job and there’s far better ways to do it.

Miller: But are there circumstances when a permanently protected area would make the most sense? I mean, what your study is specifically focused on is reducing by-catch, But my understanding is that’s not the only reason for these areas. What are the circumstances where, you know, essentially fencing off a part of an ocean, do you think would actually be a smart policy?

Hilborn: Well in general, if you’re over-fishing and you don’t have the ability to regulate the catch or the fishing effort, which is true in much of the world, then closing off some of the area to fishing makes sense. That is in those cases it’s a win, win situation – you have more catch and you have less impact. But that’s not the case in the United States. And it’s not the case in most of the places where Marine Protected Areas have been particularly put in place. Most of them have been put in places that already stopped over-fishing, and the countries that don’t regulate their fisheries are also not the ones that are putting Marine Protected Areas in place.

Miller: Ray Hilburn and Heather Mann. Thanks very much for joining us. I appreciate it.

Hilborn: Thank you for having us.

Mann: Thank you.

Miller: Ray Hilborn is a Marine Biologist from the University of Washington, the lead Author of a new study that suggests that permanently closing off marine areas to fishing may not be the best way to reduce by-catch. Heather Mann is the Executive Director of Mid-Water Trawlers Cooperative. It’s a nonprofit trade association of Nearly 30 fishing vessels. The Cooperative is based in Newport.

**Note: A “tow” is each time you pull the net on board, according to Heather Mann

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