New report outlines trawl impacts on red king crab at Bristol Bay

A new paper on trawl impacts on red king crab at Bristol Bay reveals that rules on gear are not applied equally.

by | March 30, 2022

Filed Under Environment | Management

Results of an eye-opening ‘discussion paper’ to be revealed at April NPFMC meeting

Pelagic, or mid-water, trawl net. Credit: Marine Stewardship Council

The 2021 Bristol Bay crab fishery was canceled for the first time in 25 years.

In October and December 2021, the North Pacific Fishery Management Council (NPFMC) tasked staff to prepare a discussion paper that provides the best available information on four topics related to Bristol Bay red king crab (BBRKC).

The topics include:

  1. Provide the best available information on Bristol Bay red king crab molting/mating annual cycle and how the seasonality of this overlaps with fisheries and the effects these interactions may have.
  2. Evaluate boundaries used for the BBRKC survey, stock assessment, PSC limits, and directed fishery.
  3. Provide the best available information on bottom contact by pelagic trawl gear and the impact it may have on BBRKC stocks.
  4. Summarize mechanisms used in other council managed fisheries to create flexible, responsive spatial management measures for all gear types and how they might be applied to protect BBRKC.

Federal rules to prevent crab damage, reduce bycatch don’t apply to all trawl gear

The paper reveals that the federal government applies its rules differently to on-bottom (non-pelagic) and pelagic (mid-water) gears. Three statements stand out.

My notations are in brackets [ ] —

The paper states in a footnote (#17) on Page 20 that “The Gear Limitations section of regulations (679.24(b)(4)) specifies that non-pelagic trawl gear [on bottom] may not be used to engage in directed fishing for pollock in the BSAI [Bering Sea/Aleutian Islands]. The amount of time that a trawl footrope may be in contact with the seabed is restricted in any pelagic-trawl-only portion of the Gulf of Alaska (no more than 10% of any tow), but no such limitation is specified for the BSAI.

Bottom trawl net design

Unobserved crab mortality from trawl gear on Page 28 — Rose (1999) – a paper studying the injury rates of RKC that passed under non-pelagic trawl footropes provided the following introductory statement: “The inability to accurately estimate unaccounted mortality does not preclude its consideration in management and fishing decisions. Unfortunately, the lack of information on unaccounted mortality means that those participating in such decisions have to combine and weigh a mixture of related knowledge, opinions, and suppositions to substitute for conclusive facts. This can be a source of considerable dispute and reservations about the ultimate decisions.”

Since the time of that writing, the Council has taken action to address crab mortality by raising non-pelagic trawl gear off the seafloor in a variety of ways. However, those tools are not available under the pelagic gear specifications in Federal regulation that apply to all Bering Sea pollock trawls. Unobserved mortality impacts for pelagic gear remain in the realm of informed supposition based on related knowledge. 

The unobserved mortality section also includes results of several trawl impact studies. Starting on page 29 it states:

“Published studies on the impacts of trawl gear on crab have generally focused on non-pelagic gear [on bottom],
including studies in the Bering Sea and in the shrimp fishery off the east coast of Canada. Studies have
utilized bottom and wing recapture nets to collect impacted crab that would not have ended up in the trawl
net, cameras to visualize crab that were avoiding the trawl net, and even submersible camera-equipped
vehicle dives to compare damage to crabs before and after trawling in an area.

The obvious limitation of referencing studies of non-pelagic gear is that the studies were assessing mortality reduction tools that are not permitted on the pelagic trawls that are specified in regulations for the Bering Sea pollock fishery.

The discussion paper also includes impacts to red king crab from other fishing gears. It’s an eye-opening, easy read. Find it here

Meanwhile, the pre-approved 2022 trawl bycatch level for red king crab is 80,165 animals.

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About Laine

Laine Welch has covered the Alaska fish beat for print and radio since 1988. She also has worked “behind the counter” at retail and wholesale seafood companies in Kodiak and on Cape Cod.


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