Through a quirk in Alaskan fishery quotas, more halibut are dumped dead in the ocean as waste than sold by fishermen. Of the total yearly halibut catch, a certain percentage is assigned to the legal halibut fishery, while the remainder of the quota is assigned to industrial cod and pollock trawlers that accidentally scoop up bottom-dwelling halibut as well. The cod fleet is not allowed to keep halibut, so any halibut caught must be discarded.

Over time, the catchable quota has decreased, while the discard quota has remained flat. The result is more halibut dumped rather than sold. The problem of non-target species being incidentally killed is called bycatch, and it is intractable.

Bycatch is a perennial issue since any device—hook, net, etc.—that can catch one kind of fish can catch another just as easily. One potential solution is to purchase the bycatch, tried in the 1980s in New Zealand. All fishers were entitled to a quota of a particular fishery, and the authorities agreed to buy all the out-of-quota bycatch from a vessel. The difficulty lies in setting a proper price—too high, and fishers might deliberately target a species, but too low and they’ll just dump it anyway. This is why the trawlers in Alaska have to dump their bycatch; If they are allowed to sell the expensive halibut, there is incentive to deliberately catch it.

The other approach to reducing bycatch is through technology. This approach has had some high-profile successes through the years such as turtle excluder devices in the U.S. shrimp fishery. In New England, for example, different types of devices have been attached to trawls in order to reduce the catch of juveniles and other non-desirable species, while the ruthlessly efficient brush nets were banned.

Another development is breakaway lines on lobster pots to protect passing whales from entanglement. Even the infamous gillnets can become more selective by using the latest data to set the nets only in exactly the right place and time for a particular species.

The problem is that none of these ideas go far enough. The only method that virtually eliminates bycatch is pole and line fishing in shallow water, a very limited slice of the global fishery, but even that won’t protect against overfishing.

In New England, the main tool for managers to protect fish populations is simply to limit the effort spent fishing, either through shorter seasons or buying back fishing boats to shrink the entire industry. It’s unavoidable, but reducing effort causes genuine economic hardship.

What to do? In June, the North Pacific Fishery Management Council voted to lower the allowable halibut bycatch by 25%, far less than halibut fishers were seeking. Will it be enough?