Environment

New protections are on the way for deep-sea 'trash fish'

The lowly grenadier, a deep-sea fish that nobody seems to want, is finally getting some respect.

Federal fishery managers last weekend tentatively approved a plan that will give some new protections to the odd-looking grenadiers, which are unintentionally harvested in large numbers by fishermen targeting much more lucrative species. Under the plan advanced by the North Pacific Fishery Management Council and set for final action in February, grenadiers would be formally monitored as a part of the marine ecosystem supporting the nation's largest fish harvests.

Right now, grenadiers get no such oversight. They are considered a "trash fish," a nuisance to fishermen harvesting sablefish and Greenland turbot from the icy waters off Alaska. They are lumped in an "other fish" category, and there are no limits on how much is allowed to be caught accidentally during harvests of other species.

That bycatch is considerable. An average 16,000 metric tons were hauled up annually from 1997 to 2012, according to National Marine Fisheries Service estimates based on sometimes-spotty observer data. That is about equivalent to the total Alaska catch of sablefish, the pricey species also known as black cod and butterfish.

When hauled up in longline gear, the deep-dwelling grenadiers cannot withstand the dramatic pressure changes they experience, biologists say. "One hundred percent of them die when they are brought to the surface," said Cara Rodgveller, a Juneau-based research biologist who has studied grenadiers. "They are just dead. They don't move at all."

The vast majority are discarded, though some have been used for fish meal and other purposes, she said.

Almost all of those pulled up by fishermen off Alaska are giant grenadiers, which bear the scientific name Albatrossia pectoralis; of all grenadier species, they swim the shallowest waters. A tiny percentage of the grenadiers caught off Alaska are members of two other species, Pacific and popeye grenadiers. There are at least four more grenadier species in waters off Alaska, but they swim at depths too low to be seen by fishermen, according to NMFS.

As do other creatures of the deep, grenadiers hold many mysteries. But a few facts are known.

They are related to cod and found in oceans around the world. They have big eyes, presumably needed at the depths they favor, and some species have body organs that emit light. They are long-lived, with giant grenadiers surviving over 50 years, assuming they escape predators and fishing gear. They do not reach sexual maturity until about 20. They are big -- one found by NMFS in the Bering Sea tipped the scales at nearly 92 pounds. They have long tails, the source of a less-than-flattering alternative name: "rattails." And they belong in very deep water, where they skim the sea floor at depths often below the reach of any fishing gear.

"They look very graceful underwater compared to the gray blob on the deck," Rodgveller said.

NMFS officials began assessing Alaska's grenadier stocks in earnest in 2006, she said, even though no official fishery management plan required them to do so.

At the shallowest levels of their range -- about 400 to 600 meters below the surface -- grenadiers mix with sablefish and Greenland turbot. The deeper the water, the larger the grenadiers seem to be, according to NMFS studies. There are yet more at about 800 meters, and it appears that many are swimming below the 1,000-meter level, beyond the reach of survey trawls that NMFS uses to count fish and assess biological health of sea life.

Sablefish, an apex predator, probably eat grenadiers, but few people do, said Glenn Merrill, assistant regional administrator for NMFS.

"It's just a very watery, tasteless fish. It's just never been all that palatable," Merrill said.

While there are small commercial markets in Russia, China and elsewhere for what Rodgveller and other experts say is mostly Pacific grenadier, attempts to find markets for Alaska grenadiers have fallen short. There were two experiments in Kodiak that sought to develop a reason for a grenadier harvest -- a project in 1998 investigating possible surimi production and another in 2005 investigating possible roe and fillet processing. Both projects were dropped after the first year, according to NMFS.

Grenadier dive from Alaska Dispatch on Vimeo.

Notwithstanding the large amounts of bycatch, grenadier populations in waters off Alaska seem to be healthy and in no immediate danger.

Still, NMFS and technical panels advising the North Pacific council have recommended hard limits for the catch of grenadiers. The deep-sea species would be best protected if it were in a formal fishery management plan, NMFS said in a report issued in 2012. The agency cited as justification the large numbers of grenadiers killed incidentally in the sablefish and Greenland turbot harvests and their slow reproduction.

The council's plan of action falls a bit short of that, requiring detailed counts, record-keeping and reporting -- as with other elements of the marine environment -- but no hard limits on bycatch and no requirement that the incidental caught be kept and used. Under the plan expected to win final approval in February, grenadiers would be part of the "ecosystem component" of managed fisheries rather than a specific harvest.

Seafood industry representatives have argued against a fully developed fishery management plan for the grenadier catch. Classifying grenadiers as a fishery, albeit an unintentional one, would result in having its bycatch count against the total allowable catch of targeted species with market value, reducing the value of the harvest, they said in written comments to the council. Further, a fishery management plan for grenadiers would not be worth the administrative burden, considering the healthy state of grenadier stocks, they argued. Managing grenadiers as a component of the ecosystem would accomplish the desired conservation goals most effectively, they said.

NMFS officials had deemed an ecosystem-component management option as potentially acceptable. The new classification would allow officials to watch for trends, even though overfishing limits would not be set, and would be an improvement over the current situation, Rodgveller said.

But Jon Warenchuk, a Juneau-based scientist with the environmental group Oceana, is disappointed that the council has opted for now for something less than a full fishery management plan. Given the large numbers of these slow-reproducing, "out of sight and out of mind" fish killed each year, the catch should be treated as its own harvest, and Oceana is hoping that will eventually happen, he said. Although there is a bias toward fish with market value, "Everything in the ocean is interconnected," he said.

Besides, Alaska's grenadiers might be money makers some day, Warrenchuk said. "History has shown that yesterday's trash fish might be on the dinner plate tomorrow," he said.

Contact Yereth Rosen at yereth(at)alaskadispatch.com.

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