Scallop Discos: Technique Using Lights Could Lead To More Sustainable Fishing : Short Wave Scientists in the UK have discovered that if they take a pot meant for catching crabs and just add some bright lights, scallops flock through the door like it's Studio 54. Scallops are normally fished via trawling or dredging—methods that can cause lasting damage to delicate seafloor ecosystems. So this accidental discovery (the lights were initially added to attract crab) could have a significant impact on scallop fishing. We talk with one of the scientists, Robert Enever of Fishtek Marine, a company that creates sustainable fishing gear, about this collaboration between science, industry and conservation.

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'Scallop Discos': How Some Glitzy Lights Could Lead To A Low-Impact Fishery

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EMILY KWONG, BYLINE: You're listening to SHORT WAVE from NPR.

AARON SCOTT, HOST:

Thomas (ph), are you going to share your screen for the video or...

ROBERT ENEVER: Is this the one where I swear?

SCOTT: That's Robert Enever. He's the head of science and conservation at Fishtek Marine, a company that creates sustainable fishing gear.

ENEVER: I didn't know that that one was widely available, actually. Never mind.

SCOTT: And this is a video of Rob on a boat. His team had just hauled up a crab pot from the ocean floor. It's basically this black, mesh cage, and there's some little crabs in it, as well as a bunch of shells.

ENEVER: OK. So here we are, six miles off Land's End, which is in the southwest of the U.K., on board the fishing vessel Freejays (ph). And the captain, John Ashworth, just pulled the first pot.

(SOUNDBITE OF ARCHIVED RECORDING)

ENEVER: How many scallops in that one, John?

As you can see everyone's really excited.

(SOUNDBITE OF ARCHIVED RECORDING)

JOHN ASHWORTH: Two, three, four...

ENEVER: He's got a dozen or so scallops in there. And that's something that no one's ever - ever - seen before.

(SOUNDBITE OF ARCHIVED RECORDING)

ASHWORTH: There's half a dozen. One, two, three...

SCOTT: Scallops hang out on the seafloor, but they don't normally swim into crab pots. This video captures the moment that Rob and some of his colleagues came across an accidental discovery.

ENEVER: And so every time we hauled a pot with lights in, it had scallops. And every time we hauled a pot that didn't have lights, it just didn't have scallops. And, you know, it was that eureka moment. And for some reason, no one stumbled across this before. It's 2022. Like, I just don't understand why no one's actually discovered this because, you know, this is the potential for a new fishery here, and a low-impact fishery. I was massively skeptical.

SCOTT: He was skeptical because normally, people gather scallops through practices that can damage the seafloor. But if they could lure those scallops to swim into the pots on their own, well, that could be transformative for the industry. What's remarkable is they weren't even looking for scallops in the first place.

ENEVER: So we were experimenting with lights in fisheries.

SCOTT: Back in 2019, they were testing to see if LED lights attached to the pots might attract the crabs and lobsters, instead of having to lure them in with expensive bait.

ENEVER: And so one of my colleague was a fisherman, a lobster fisherman. And so we sent him a bunch of lights. And we said, just tell us what happens.

SCOTT: A month later, the fisherman got back in touch.

ENEVER: He said, well, no, no. There was no real noticeable increase or decrease in crab or lobster. But I did notice, you know, there are a lot of scallops turning up in the pots. And these pots are not designed, whatsoever, to catch scallops. And so I said, well, you know, for context, you know, what would you see in a year in - when you shoot your pots? And he said probably about five scallops out of 35,000 pots.

SCOTT: Wow.

ENEVER: And I said, well, what were you seeing this time? And he was like, about 10 to 15 for every 50 pots. So it was like a 1,500-fold increase. And so we applied for some funding to undertake some proper trials. And that video was the first time we went aboard and hauled the pots.

SCOTT: Robert and his team had stumbled onto a scallop disco. We still don't completely understand why the little bivalves go towards the light, but it's clear they're lining up at the door like it's Studio 54. And that could point toward a new and less-damaging way to fish for them. So today on the show, science, industry and conservation converge on a humble sea creature. I'm Aaron Scott, and you're listening to SHORT WAVE, the daily scallop pot-cast from NPR.

(SOUNDBITE OF MUSIC)

SCOTT: For those who are not familiar with these delightful little creatures, what are scallops? What do they look like? What do they do? Where do they fit into the ecosystem?

ENEVER: Scallops are kind of like a clam. They've got two sides, and they kind of cover themselves with a little bit of sand. And they sit there, filter feeding, and they keep the environment nice and clean. They're food for, you know, octopus or lobster or other marine animals. So they're just an important part of the ecosystem. But they also are particularly tasty - food item (laughter). And they're - you know, they're very delicious. And because of that, there's fisheries all over the world that harvest them.

SCOTT: So, Rob, how are scallops usually fished?

ENEVER: So traditionally, maybe 95% of landed scallops are caught using either trawls or dredges. And these are fishing gear types that interact with the seabed. A dredge, for example, has teeth on it. And those teeth penetrate the seabed and lift the scallops up into metal bags. A terrestrial equivalent might be a plow going through a wildflower meadow.

SCOTT: And so what does that then mean to the seabed? How does that affect all the other critters that are living down there?

ENEVER: It depends on what the seabed is. If it was, like, a reefy (ph) environment, you know, sedimentary environment with fragile sponges and, like, slow-growing, long-living species, that - if you put a dredge through that, it will utterly destroy it for a decade. And, you know, that's been shown.

SCOTT: But so there's the possibility we could change all that with the addition of just some good lighting. So, Rob, tell us about how lights first got on your radar as something to catch crab and maybe even scallops.

ENEVER: So there's a group of scientists in Memorial University in Canada that looked into the impacts of light on snow crab. And they realized that if you use light in traps, with bait, it increased the catch rate of snow crabs. And we were like, wow, that's something that we should look into because in the market out there, there's not a low-cost, you know, light that can go down to a thousand meters. It's all really expensive equipment. And we were like, well, if we can make something, this could be really transformational in terms of how fishermen catch. They don't have to use bait. I mean, bait supply is a massive issue.

SCOTT: And so you were working to figure out kind of affordable lights that could go down here, and then suddenly scallops also took a liking to them. Can you tell us a little bit about what you've found as you've tested this further and what sort of results there are, in terms of just how many scallops are attracted to light?

ENEVER: We've been working in, like, a lab facility here at Fishtek where we set up tanks. We've been putting the scallops in the tank, seeing if we can replicate what happens in the natural environment in a sort of tank condition. And sure enough, we can. So if you put a light at the end of the tank and the scallops in the middle, then they swim towards the light. And that's brilliant for us because we can then say, right, what if we changed the color of the light or the light intensity or whether that light flashes and things like that? So what we've actually discovered is actually, the white light probably wasn't the best light. We've concluded that the blue lights are - seem to be the ones that the scallops are really attracted to.

SCOTT: The idea that scallops can see is surprising enough - the idea that they can see different colors of lights. Can you tell us a little bit about kind of the amazing thing that is, or are, scallop eyes and why you think they might actually be attracted to different colors of light?

ENEVER: It's a good question. I mean, they've got very basic vision. They have 200 - up to 200 eyes, each scallop. But it's not like...

SCOTT: Two-hundred eyes.

ENEVER: ...The vision that you and I would have. It is very basic, light-dark, shadow information going on there. And so the idea that - you know, that they can actually see the trap or see anything is - I don't think it's that clear-cut. I think it is - our thinking is that they're able to pick out if there's zooplankton or plankton around the light, like moths to a flame, that they're able to swim to that and get an optimal...

SCOTT: OK.

ENEVER: ...Feeding environment, and they can pick out their prey items for feeding more easily.

SCOTT: And so, I mean, it's really cool in the way that this is not just, you know, learning a better fishing technique, but it's almost like we're learning something about scallops and mollusk vision and biology.

ENEVER: Totally. Like, so, I mean, we are liaising with, like, the scallop experts in the world on this, and they're blown away. Like, you know, there's a guy in the states - Professor Speiser. He's been advising us. And he's a neurobiologist and looks at the optimal wavelengths of light being received by scallops. And he's the one that sort of suggested, try blue light. So, I mean, we've had the footage that you guys have seen of the scallops swimming to the light and equally, you know, these scallop scientists - eminent scallop scientists all over the world - are really surprised by this. So there's plenty of Ph.D.s working out why they're doing it. But for us, it's just an opportunity here to have a low-impact fishery.

SCOTT: So I got to ask, who and how did you all come up with the name scallop discos?

ENEVER: Oh, that is a great question because (laughter) it wasn't me. And, like, because I'm a scientist by heart, I found that a little bit uncomfortable to go out with scallop disco. Because firstly, the light wasn't flashing and it wasn't multi-colored. And so, like, my - (laughter).

SCOTT: So you're - the scientist in you that would describe disco lights is feeling uncomfortable that it's...

ENEVER: Yeah, exactly. But we went with it and, my goodness, what exposure it got by having the hashtag #scallopdisco. And that was brilliant because you know, if it was left to me, it would have just been really boring and scientific and factual. But actually, when you get, you know, someone who's involved in media in these things, then the exposure, globally - like, I wouldn't be doing this interview, I'm sure - and so the opportunities to then apply this in other fisheries, globally, are massively increased as a result of a silly strapline, which is essentially what it was.

(LAUGHTER)

SCOTT: Wow, the powers of marketing, which really gets to...

ENEVER: Yeah, totally.

SCOTT: ...To - I mean, the question that we wanted to know is, I mean, what sort of impact do you hope this could have on the fishing industry? And do you think it could actually replace dredging, or do you think it will be more of kind of the organic version of scallop fishing?

ENEVER: Yeah, I don't think it's going to replace scallop dredging entirely. If we just take the U.K., for example, I think there's something like a hundred million scallops caught every year. Now, you got to catch a lot of scallops in your pots to start, you know, making a dent on that. But these are going to be a premium product. They're going to sell for more. They're going to be caught by people that have never caught them before. In the U.K., and as in the States and elsewhere in the world, there's lots more marine-protected areas getting set up. So any opportunity for a more sustainable, low-impact form of fishing is something that people will, you know, pursue.

SCOTT: Which is really interesting. I mean, we spend a lot of time on this show talking to scientists at, you know, universities and labs or government agencies who are kind of doing the basic research. You're doing the research, but then you're also having to find and develop the commercial application for the company you work for, Fishtek.

ENEVER: Yeah.

SCOTT: Can you talk a little bit about kind of the pros and cons of being involved both in the research side, but also doing it for, you know, a for-profit company? What are the pros and cons of navigating that?

ENEVER: So if I was doing this job and I worked in government or, you know, academia, it wouldn't happen quickly. It would be slow, protracted and very expensive. So the private sector are able to be much more nimble. If we need to change our mind, you know, we can do it really quickly. And we work, you know, efficiently and cheap because, you know, we're trying to run a profit. But because we're a private-sector company, I guess the negatives are that we're not necessarily considered as scientific as someone from a government institution or academia or something like that because you've got a profit motive. And, you know, you get thrown, well, you would say that, wouldn't you? So what we try to do to mitigate that is to work closely with academia and universities and have, like, an arm's-length relationship. So our science is really independent. And that's important because, you know, I'm a scientist at heart. You know, there's absolutely no way I'd break that Hippocratic oath of honesty and truth just to make a quick buck. That's not going to happen.

(SOUNDBITE OF SONG, "SEEING COLOURS")

RIVER POLICE AND SARAH BERRESFORD: (Singing) Color in my heart, color in my head, seeing red.

SCOTT: Rob, thank you so much. It's been a joy to talk with you.

ENEVER: Yeah, you too. Thanks, Aaron.

SCOTT: This episode was produced by MC Thomas Lu, edited by DJ Gabriel Spitzer and fact-checked by four-on-the-floor Rachel Carlson. The audio engineer was Disco Stu Rushfield. Gisele Grayson is our senior supervising editor, Beth Donovan is our senior director and Anya Grundmann is our senior vice president of programming. Before we turn off the music, quick shoutout to our SHORT WAVE+ listeners. We appreciate you all. Thank you for being subscriber's. SHORT WAVE+ helps support our show. And if you're a regular listener, we'd love for you to join. It means you can listen every day without sponsor interruptions. Find out more at plus.npr.org/shortwave. That's plus.npr.org/shortwave. I'm Aaron Scott. Thanks for listening to SHORT WAVE, from NPR.

(SOUNDBITE OF RIVER POLICE AND SARAH BERREFORD'S "SEEING COLOURS")

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