A candid conversation with MSC fisheries expert Marin Hawk about unwanted catch and how sustainable fisheries work to reduce it.

“Fishers don’t want bycatch. I know people say that all the time, but it’s true,” explains Marin Hawk, MSC Senior Fisheries Program Manager for the Americas.

“It’s bad for the longevity of their fishing gear – it won’t last as long if they catch things the gear wasn’t meant to catch. It also often triggers management procedures which take a lot of time and effort; and it can impact the population of the fish species they’re actually trying to catch. So, it’s in their best interest to avoid catching any unwanted species.” 

But let’s backup for a moment – what actually is bycatch and, if fisheries try to avoid it, how does it still happen? 

What is bycatch?

Experts agree that bycatch is marine species that are unintentionally caught while fishing for another species. But there’s no one official definition that’s accepted around the world; it can mean different things to different people. For example, some unintentional catch gets thrown back overboard, which is wasteful, but some can be kept and sold, which isn’t necessarily bad.

To our resident fisheries expert Marin Hawk, and many others in the fishery management world, bycatch is specifically understood to be catch that gets discarded.

“There’s a difference between non-target catch and bycatch,” says Hawk. “When a fishery heads out to the water, they’re typically targeting a specific species. For example, yellowfin tuna. If they catch a species that’s not yellowfin tuna, like swordfish, they might be allowed to keep and sell that swordfish, which will then get eaten. So that’s not bycatch. That’s non-target catch.” 

These varying definitions can cause confusion. At the MSC, where our whole organization is based on a global standard that can be applied to any (wild) fishery anywhere in the world, we need to be much more specific. 

What is unwanted catch?

At the MSC, we used the term “unwanted catch” to encompass the wide range of species that might be unintentionally caught in fisheries. This includes undersized or extra individuals that fisheries do not have quota for, endangered, threatened, and protected (ETP) species, and unwanted "non-target" species, which are ones that the fishery is not specifically trying to catch when fishing.

Can fisheries with bycatch be sustainable?

Fishing activity with unwanted catch can still be sustainable as long as any and every population that’s impacted remains healthy.

Hawk puts it simply: “It’s all about whether the amount of unwanted catch harms the population such that it cannot continue to reproduce.”

Most sustainable fishing will include some level of unwanted catch. That’s the reality of catching wild fish that mix and mingle with other species and all kinds of marine environments.

“Unwanted catch can be difficult to avoid when we’re trying to feed the world with wild fish, purely because of the volume of fish caught around the world” Hawk says.

The key is whether it causes significant impact to the population of the species that are impacted. For example, even if only a few individuals of a particular species get caught, it is unlikely to have a lasting impact.

“If bycatch exists, it’s better that it happens in MSC certified fisheries than in non-certified ones, because of continued monitoring within the MSC program and requirements to meet MSC’s high bar for certification,” Hawk explains.

How does the MSC deal with unwanted catch?

Put simply, unwanted catch in MSC certified fisheries must not cause serious or irreversible impact to the marine species affected.

“In order to be MSC certified, a fishery must characterize all of its bycatch,” Hawk says. “Which means that the fishery has an exact percentage of how much of each species is caught. That unwanted catch is then judged based on the volume and health of the impacted populations.”

For example, if a fishery catches a vulnerable species, like a hawksbill sea turtle, it will fall into a very precautionary bucket, and any interactions or unwanted catch will result in lot of work with fishery managers and extensive information collection. But if we use our tuna and swordfish example from earlier, as long as the number of swordfish unintentionally caught isn’t harming the overall population and falls within quotas, then it’s acceptable. 

“I also think the other really important thing about MSC certified fisheries that do have bycatch is that they are incentivized to reduce that bycatch,” Hawk notes. “Every time they enter a new version of our fisheries standard, it's likely that they will have to continue to make improvements on that bycatch.”

A fishery that's not MSC certified doesn't have that incentive and can continue catching bycatch with little oversight.   

Additionally, Hawk reminds us that in the MSC program “there’s a mechanism in place to suspend the fishery if unwanted catch is shown to have detrimental impacts on another population.” 

Have MSC certified fisheries reduced bycatch?

There are dozens of examples of MSC certified fisheries making improvements to fishing gear, avoiding a particular location, or altering fishing seasons to reduce bycatch. 

Hawk shared a few examples: “The Suriname Seabob fishery (a species of shrimp) installed turtle excluder devices on their trawls and dramatically reduced interactions with sea turtles.

The US spiny dogfish fishery put acoustic pingers on their gillnets to deter porpoises from trying to eat fish from the nets, preventing them from getting entangled.

And the Alaska flatfish fishery put new ‘web fences’ on the front end of their trawls to prevent whales from entering the net, resulting in an 89% reduction in whale interactions.”

Fishers, environmentalists, and fishery managers alike all want to reduce bycatch. These three fisheries are just a quick sampling of all the improvements that have been made over the life of the MSC. While it’s unlikely that unwanted catch could ever be completely eliminated, better data, continually improving management, and ever evolving best-practices will make unwanted catch a smaller and smaller part of each fishing trip. 

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