Fisheries of the Exclusive Economic Zone Off Alaska; Rebuilding Overfished Fisheries

AGENCY:

National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration (NOAA), Commerce.

ACTION:

Approval of a fishery management plan amendment.

SUMMARY:

NMFS announces the approval of Amendment 14 to the Fishery Management Plan for the Bering Sea/Aleutian Islands King and Tanner Crabs (FMP). This amendment contains a rebuilding plan for the overfished stock of Bering Sea snow crab. This action is necessary to ensure that conservation and management measures continue to be based upon the best scientific information available. It is intended to enhance the Council’s ability to achieve, on a continuing basis, optimum yield from fisheries under its authority.

DATES:

The amendment was approved on December 28, 2000.

ADDRESSES:

Copies of Amendment 14 to the FMP and the Environmental Assessment (EA) prepared for the amendment are available from the Sustainable Fisheries Division, Alaska Region, NMFS, P.O. Box 21668, Juneau, AK 99802-1668, Attn: Lori Gravel.

FOR FURTHER INFORMATION CONTACT:

Gretchen Harrington, 907-586-7228 or gretchen.harrington@noaa.gov.

SUPPLEMENTARY INFORMATION:

NMFS declared the Bering Sea stock of snow crab (Chionoecetes opilio) overfished on September 24, 1999, because the spawning stock biomass was below the minimum stock size threshold defined in the FMP. On September 24, 1999, NMFS notified the Council that the stock was overfished (64 FR 54791, October 8, 1999). The Council then took action to develop a rebuilding plan within 1 year of notification as required by section 304(e)(3) of the Magnuson-Stevens Fishery Conservation and Management Act (Magnuson-Stevens Act).

In June 2000, the Council adopted Amendment 14, the rebuilding plan to accomplish the purposes outlined in the national standard guidelines to rebuild the overfished stock. Amendment 14 specifies a time period for rebuilding the stock that satisfies the requirements of the Magnuson-Stevens Act. Under the rebuilding plan, the Bering Sea snow crab stock is estimated to rebuild, with a 50 percent probability, within 10 years. The stock will be considered “rebuilt” when it attains the maximum sustainable yield stock size level for 2 consecutive years.

The rebuilding plan consists of a framework that references the State of Alaska’s harvest strategy, bycatch control measures, and habitat protection measures. The plan uses the harvest strategy developed by the Alaska Department of Fish and Game. The harvest strategy was reviewed and adopted by the Alaska Board of Fisheries. The FMP defers development of harvest strategies to the State of Alaska, with oversight by NMFS and the Council. The rebuilding harvest strategy should result in more spawning biomass because more large male crab would be conserved and fewer juveniles and females would die due to incidental catch and discard mortality. More spawning biomass would be expected to produce larger year-classes when environmental conditions are favorable. Protection of habitat and reduction of bycatch may reduce mortality of juvenile crabs, thus allowing a higher percentage of each year-class to contribute to spawning and future landings.

The Council prepared an EA for Amendment 14 that describes the management background, the purpose and need for action, the management alternatives, and the environmental and the socio-economic impacts of the alternatives. A copy of the EA can be obtained from NMFS (see ADDRESSES).

A notice of availability for the proposed Amendment 14 to the FMP, which described the proposed amendment and invited comments from the public, was published in the Federal Register on September 29, 2000 (65 FR 58501). Comments were invited until November 28, 2000. NMFS received two comments.

Response to Comments

Comment 1: The rebuilding plan does not contain meaningful bycatch reduction measures and habitat protection measures. Given the large amount of information that is unknown about the biology of the stock, the amount of bycatch mortality from the various sources, and habitat needs of the stock, it is imperative that NMFS employ a large amount of precaution in this rebuilding plan. The commenter advanced these particular concerns about the rebuilding plan: (1) The discussion in the EA of higher probabilities of rebuilding under the alternatives is insufficient; (2) NMFS should reduce the snow crab bycatch limit in the trawl fisheries and should comprehensively study the bycatch mortality of snow crab captured in trawl gear; (3) NMFS should study snow crab bycatch mortality in the snow crab fishery and the effects of ghost fishing and the impacts of pot gear on snow crab and their habitat; (4) NMFS should determine the bycatch mortality for snow crab in the longline, groundfish pot, and scallop fisheries; (5) NMFS should study the habitat needs of snow crab to best protect essential habitats for the stock and the annual NMFS Eastern Bering Sea trawl survey is inadequate for providing information on snow crab habitat; (6) NMFS should study the current and potential effects of trawling on snow crab habitat; and (7) The preferred alternative for habitat protection does not provide meaningful habitat protection. In light of the uncertainties, NMFS must be precautionary and protect any possible snow crab habitat from adverse impacts. NMFS should consider a seasonal bottom-trawl closure from March to June in areas of highest trawl bycatch to protect snow crab during sensitive life-stages and a permanent bottom-trawl closure north of 58° N lat., protecting 82 percent of female crabs.

Response: NMFS agrees uncertainties exist about the biology of snow crab and that more scientific research needs to be conducted on its habitat, bycatch mortality in all fisheries, and the effects of all types of fishing gear on habitat. The EA highlights all of the areas where more research is needed, including those research needs identified by the commenter. The scientific uncertainties were adequately considered and accounted for in developing alternatives for the rebuilding plan. The rebuilding plan incorporates these uncertainties, provides for protection and rebuilding of the snow crab stock, and provides for a modest fishery.

NMFS has determined that the current rebuilding plan is sufficiently precautionary. The EA identifies all known sources of snow crab mortality, analyzes each one, and examines the most effective measures to rebuild the stock. By far, the largest source of mortality and bycatch of snow crab is in the directed snow crab fishery. In 1999, the directed fishery accounted for approximately 95 percent of the total snow crab bycatch in all fisheries. As the EA illustrates, the rebuilding plan greatly curtails the directed fishery. By comparison, all other sources of bycatch and bycatch mortality are minimal and amount to less than 1 percent of the snow crab population, even when assuming 100 percent mortality. Likewise, existing evidence does not indicate that the decline in snow crab abundance is due to habitat destruction by fishing gear. The vast majority of female and juvenile snow crab live in the northern regions of the Bering Sea where few or no fisheries operate.

Responses to each specific point made by the commenter are as follows: The rebuilding time period satisfies the requirements of section 304(e)(4)(A) of the Magnuson-Stevens Act. The rebuilding plan is estimated to allow snow crab to rebuild, with a 50 percent probability, to the Bmsy level within 10 years. A 50 percent rebuilding probability within 10 years is the estimated probability recommended in the NMFS technical guidance for rebuilding overfished stocks. This probability of rebuilding includes the conservative parameter that the stock will be considered ‘rebuilt’ when the stock size reaches the Bmsy in 2 consecutive years. NMFS and ADF&G stock assessment experts, who developed the model used to estimate the rebuilding times and probabilities, determined that a 50 percent probability best represented reality given the biology of the species and the current level of scientific information.

The EA estimates the rebuilding time of each alternative at a 10 percent, 50 percent, and 90 percent probability. The alternatives range from zero catch (no directed catch and no bycatch in the trawl fisheries) to the traditional harvest rate of 58 percent of males greater than or equal to 4 inches (102 mm). None of the alternatives, including zero catch, would achieve rebuilding at a 90 percent probability within 10 years.

The exercise of estimating rebuilding probabilities provides managers with an idea of the potential outcomes of different alternatives and helps managers predict whether the alternatives will rebuild the stock within 10 years. However, the components of the rebuilding plan were developed, taking into consideration the full breadth and depth of current scientific understanding and not solely based on the results of the models.

The EA analyzes the option of reducing the snow crab bycatch limit in the trawl fisheries. Under the existing program, NMFS closes trawl fisheries when they reach their snow crab bycatch limits. The Council considered the following points when it determined that the existing snow crab bycatch controls for the trawl fisheries are sufficient. First, reductions in bycatch most likely would not result in measurable improvements to snow crab abundance because the 7-year average annual bycatch of snow crab in the trawl fishery is only about 0.1 percent of the total abundance. Second, current bycatch limits provide incentives for the trawl fleet to avoid concentrations of snow crab, thus keeping bycatch rates well below the limit. Finally, reductions in limits would disadvantage specific sectors of the trawl fleet because of the way bycatch limits are apportioned by fishery before the fishing season. Therefore, the Council determined that the very small potential for measurable improvements in snow crab abundance did not justify the disproportional economic disadvantages that would have resulted from bycatch limit reductions.

NMFS concurs that more studies need to be conducted to determine the mortality of snow crab caught as bycatch in the trawl fisheries. Given this lack of information, a very conservative mortality rate of 80 percent was used in the analyses of alternatives. In addition, assuming that all snow crab caught in the trawl fisheries die, crab mortality caused by the trawl fisheries would equal about 0.1 percent of the total abundance of snow crab.

NMFS concurs that additional research is needed on snow crab bycatch in the directed snow crab fishery, the effects of ghost fishing (lost pots that continue to catch crab and other species), and the impacts of pot gear on habitat. As noted by the commenter, State regulations require all pots to have degradable mesh that acts as an escape mechanism to prevent ghost fishing. Also, as noted in the EA, pot loss has greatly diminished since the State established pot limits in the crab fisheries in 1992. The rebuilding plan implements a precautionary harvest strategy that protects the stock at low abundance from the effects of the directed fishery. When abundance is very low, the rebuilding harvest strategy closes the fishery, which stops all snow crab bycatch in the snow crab fishery. Likewise, the harvest strategy provides for harvest at a reduced rate as abundance increases. A reduced harvest rate means a reduction in bycatch. In addition, because the fishing effort is greatly reduced with reductions in harvest levels, so presumably are the effects of the fishing gear on habitat. Further, the State’s gear modification measures adopted under the rebuilding plan will reduce the number of females and small males caught per pot in the directed fishery. So, although scientific uncertainty exists on the effects of bycatch and pot gear on habitat, the rebuilding plan reduces bycatch and the amount of gear deployed by curtailing harvest when stock abundance is low. NMFS concurs that more research should be conducted on bycatch mortality of snow crab in the longline, groundfish pot, and scallop fisheries. However, according to observer data, bycatch of snow crab in these fisheries is minuscule. The 7-year combined average total bycatch for these fisheries is 426,950 crabs, which is 0.013 percent of the 2000 abundance estimate of 3.2 billion snow crabs. The commenter notes the increase in bycatch of snow crab in the scallop fishery. This is due to an expansion in the range of snow crabs into scallop fishery grounds during the mid-1990’s when snow crab abundance was high, rather than to an expansion in the distribution of the scallop fishery. NMFS concurs that more research should be conducted on the habitat needs of snow crab. NMFS plans to conduct additional research on the habitat needs of snow crab as funding is available. NMFS also concurs that the NMFS trawl survey might be inadequate for providing information on snow crab habitat and that the survey does not cover the full extent of snow crab habitat. However, snow crab habitat that exists outside the survey area is not subject to any commercial fishing pressure. Because the survey is designed to estimate abundance of commercially important crab and groundfish species, it is conducted in those areas where commercial fishing occurs and it does not extend beyond the areas used for commercial fishing.

NMFS concurs that additional research is needed on the current and potential effects of trawling on snow crab habitat. NMFS plans to conduct additional research on the effects of trawling on snow crab habitat as funding is available.

NMFS believes the preferred alternative for habitat protection does provide adequate habitat protection. The Council may choose to develop new habitat protection measures in the future to incorporate into the rebuilding plan. However, as explained in the EA, the research conducted to date does not show substantial adverse impacts from trawling on snow crab habitat. The EA reaches this conclusion because (1) trawl effort is low in areas identified as important for females and juvenile snow crab, and (2) current bycatch control measures provide incentive for the trawl fleet to avoid areas of high concentration of snow crab, thus avoiding snow crab habitat.

The Council considered a seasonal bottom-trawl closure from March to June in areas of highest trawl bycatch. It concluded that this closure may have many unintended consequences by displacing trawl effort, including moving trawl effort to areas of sensitive habitat for other crab species, increasing bycatch of other sensitive species like halibut and Tanner crab, and concentrating trawl effort. The reported high bycatch is a function of high trawl effort and not of high snow crab abundance in that area. Further, the Council could not identify measurable benefits of this proposed time/area closure. It would not be in place during the snow crab molting and mating period. The proposed area is a relatively small portion of snow crab habitat and is not an area historically important for snow crab reproduction. The areas identified as important for snow crab reproduction extend north of 58° N lat., where some trawling occurs in limited areas. Thus the predicted benefits of closing this area would be small compared to the predicted consequences.

The EA analyzes a possible bottom-trawl closure north of 58° N lat. The commenter is correct in stating that a closure of the area north of 58° N lat. would protect approximately 82 percent of female crabs. However, less than 2 percent of the trawl effort occurs above 58° N lat. And that trawl effort occurs near the 58° N lat. line. Most of the area above 58° N lat. is not subject to any fishing effort. The Council could not find measurable benefits to moving this small amount of trawl effort to below 58° N lat.

Comment 2: NMFS should delay approving Amendment 14 until a thorough scientific analysis of the snow crab stock status and the rebuilding plan are complete because the rebuilding plan may be an over-reaction to a flawed definition of overfishing for snow crab. The commenter advanced these particular concerns about the rebuilding plan’s conservative harvest strategy: (1) Snow crab are not “overfished” because fishing did not cause the decline in abundance. Further, the commenter quotes the Council’s Scientific and Statistical Committee’s opinion that NMFS should change the national standard guidelines at 50 CFR 600.310 so that stocks with low abundance are not determined to be “overfished” when fishing had no demonstrable effect; (2) NMFS scientists acknowledge that the time constraints set by the Magnuson-Stevens Act for developing the rebuilding plan did not allow for the new harvest strategy to benefit from a thorough analysis of many aspects of snow crab biology and that a more thorough analysis may justify a less conservative harvest strategy; (3) The traditional harvest rate of 58 percent of males 4 inches (102 mm) or greater is precautionary because the legal size for snow crab is 3.1 inches (79 mm). Thus, sexually mature males have years to fertilize females before they are captured by the fishery (The legal size limit for snow crab is 3.1 inches (79 mm), based on the size at sexual maturity of male snow crab. For market reasons, the industry standard is to only harvest males 4 inches or greater.); (4) The reduction in the harvest rate under the rebuilding plan will only increase recovery time of the stock by 6 months compared to the rebuilding time under the traditional harvest rate, as shown in the rebuilding probability simulation; and (5) The cost of the rebuilding plan, which involves hundreds of millions of pounds of foregone catch, greatly outweighs the benefit of the rebuilding plan, which is a 6-month increase in rebuilding time. Therefore, the commenter concludes that NMFS does not have adequate scientific information to reduce the harvest rate for snow crab.

Response: NMFS has determined that the rebuilding harvest strategy is based on the best scientific information available and is intended to rebuild snow crab to historic levels of abundance. As explained in the EA, existing scientific information supports a reduction in the harvest of snow crab to rebuild the stock.

The commenter assumes that a delay in approving the rebuilding plan would result in a fishery under the traditional harvest rate of 58 percent of males with a carapace width of 4 inches (102 mm) or greater. This is not the case because the harvest strategy in the rebuilding plan was adopted into regulation by the Alaska Board of Fisheries in March of 2000.

Responses to each specific point made by the commenter are as follows: According to the national standard guidelines at 50 CFR 600.310(d)(1)(iii), the term “overfished” is used to describe any stock or stock complex whose size is sufficiently small enough that a change in management practices is required in order to achieve an appropriate level and rate of rebuilding. Thus, NMFS determined snow crab is overfished because snow crab abundance was below the threshold established for the stock. The cause of the decline in snow crab abundance is irrelevant to a determination that a stock or stock complex is sufficiently small that management changes are needed.

The 1-year requirement in section 304(e)(3) of the Magnuson-Stevens Act is intended to assure that action is taken in a timely manner to protect depleted populations and populations vulnerable to overfishing. Notwithstanding the short time period to protect vulnerable populations, all management actions must be based on the best science available at the time of the decision. NMFS determined that the rebuilding plan for snow crab is based on the best available scientific information that shows the population sharply declined between 1998 and 1999, that the snow crab population is aging, and that very few juvenile crab exist to grow into the fishery. In addition, as detailed in the EA, the scientific uncertainties were adequately considered and accounted for in developing alternatives for the rebuilding plan.

The framework structure of the rebuilding plan is designed so that changes can be made to the plan based on analyses conducted by NMFS, the Council, and State scientists. If the results of these analyses indicate that the harvest strategy should be modified, then it will be modified through the Board process and reviewed by NMFS and the Council, as specified in the FMP.

As explained in the EA, the traditional harvest rate of 58 percent of males 4 inches (102 mm)or greater is not precautionary and can result in overfishing during periods of poor recruitment, such as the stock has recently exhibited. Evidence suggests that continuing the previous 58 percent harvest rate on this stock may jeopardize its rebuilding by removing a majority of the largest males and causing high bycatch.

High harvest rates on large mature males may also possibly impact reproductive potential of a stock by reducing the size of males available for breeding. The low stock levels observed for eastern Bering Sea snow crab during the 1999 survey were accompanied by indications of poor reproductive potential. Mature female snow crabs examined during the 1999 survey were barren at higher than normal rates and showed lower than normal rates of full clutches. Circumstantial evidence shows fishery-induced selection for reduced size or age at maturity in males. Any of these conservation concerns related to harvesting of large males would become more acute when stocks are low because of the greater impact of chance events at low stock levels. Thus, the condition and composition of the stock were the primary considerations that lead to the conservative harvest strategy.

The rebuilding harvest strategy reduces the harvest rate because lower harvest rates must be applied to depleted stocks and those with high levels of uncertainty about their productive capacity. This reduction in the harvest rate is not only required, but it is also prudent for stocks with periodic recruitment, like snow crab. A reduced harvest rate also reduces snow crab bycatch in the directed snow crab fishery because the season is shorter and gear is on the grounds for a shorter amount of time.

The commenter is correct in stating that the rebuilding time under the rebuilding harvest strategy is estimated to be 6 months shorter than under the traditional 58 percent harvest rate. This prediction is based on the outcomes of the recruitment models used to estimate the rebuilding times of the alternatives. The EA fully explains the length-based simulation models used and the limits of the model results due to the lack of a stock-recruitment component. For these models, recruitment means the number of crab in cohort that survive from the time they are hatched until they reached 35 to 50 mm, the size at which there are abundance estimates.

The time to rebuild is highly dependent on the model’s assumptions about future recruitments. None of the recruitment models used in the analyses includes any role for the effects of the spawning stock on future reproduction. This is because the relationship between the existing spawning stock size and the number of recruits this stock will produce is not known. From analyzing historic information, variability in recruitment is known to be high. Large spawning stocks are known to produce small numbers of recruits. Likewise, small spawning stocks are known to produce large numbers of recruits. At present, no studies have been performed to identify and model the factors determining or influencing recruitment to the snow crab stock. Physical-oceanographic factors probably have a strong influence on recruitment of snow crab in the eastern Bering Sea. Biological factors that are unrelated to spawning stock size could also be important determinants of the strength of recruitment.

The lack of a stock-recruitment component in the models reflects the inability of the analysts at the current time to specify a model relating spawning stock conditions to future recruitment, rather than any conclusion on the part of the analysts that no such relationship exists.

Due to this lack of a stock-recruitment component, these models do not allow for any feedback from the effects of management measures to future recruitment. The models used here are adequate for modeling the short-term (the next 15 years) recovery of the stock, because the short-term stock dynamics will not be influenced by the present reproductive potential of the stock due to the time lag from spawning to recruiting. On the other hand, the models will not adequately represent any long-term effects due to harvesting mature males.

Important conservation consequences may result from different harvest rates applied to large males. Those consequences are not revealed in the model results. First, given the nature of the recruitment models used, any conservation benefits that may result from preservation of large male crabs within the spawning population through more conservative management, will not be reflected in the model results. The rebuilding simulations were conducted to estimate rebuilding times given the current level of scientific information, not to model all of the possible effects of the alternative harvest strategies.

Second, as shown in the EA, a high harvest rate on a stock with low population levels is risky for the long-term health of the stock. Research suggests that density dependent factors and other risks associated with harvesting a high rate of large males may exist when the stock is declining. Although environmental effects are important in effecting variation in recruitment and the snow crab fishery removes only the larger mature males from the stock, the possible effects on future recruitment due to the fishery should not be discounted.

The assumption that the only benefit of the rebuilding harvest strategy is a savings of 6 months in rebuilding time is incorrect. NMFS expects that the conservative harvest strategy will increase the abundance of snow crab by the preservation of large male crab and the reduction of bycatch of female and sublegal male crab. The primary goal of a rebuilding plan is to rebuild the stock to a biomass level that will produce maximum sustainable yield. Maximum sustainable yield provides the greatest catch and the greatest income to the fishermen and fishery-dependent communities over the long-term. Often, foregone catch in the short-term is necessary to have a high sustainable yield in the future.

The commenter states that the cost of the rebuilding harvest strategy is high levels of foregone catch. The commenter assumes that the snow crab stock would continue to support a fishery at a high harvest rate and that the fishery will rebuild if subject to a high harvest rate. As discussed above and detailed in the EA, scientific evidence shows otherwise. Continuing under the harvest rate of 58 percent runs the risk of causing the further decline of the stock.

The commenter estimates the future foregone catch based on a graph produced by ADF&G. From this graph, the commenter concludes that future harvest of snow crab will be hundreds of millions of pounds less that it would be under the traditional 58 percent harvest rate. The ADF&G graph compares the historic annual guideline harvest levels under the previous harvest rate to estimates of what the guideline harvest levels would have been if managers had applied the rebuilding harvest strategy in those years. As the graph shows, it does not model the potential increase in stock size due to greater carry-over of mature and harvestable stock that would have occurred from year-to-year under a more conservative harvest rate. This carry-over would have resulted in higher stock abundance, higher harvests than shown in the graph, and may have prevented the sharp declines in abundance that we saw under the previous harvest rate. Therefore, the assumption that, once the stock rebuilds, future harvest levels will be dramatically lower under the rebuilding harvest strategy than under the traditional 58 percent harvest rate is not accurate.

The Council has met the requirements of the Magnuson-Stevens Act and complies with the national standard guidelines by creating a rebuilding plan that reduces harvest when the stock is at low levels. The Magnuson-Stevens Act at section 303(a)(10) mandates that when the Secretary determines a stock is overfished, conservation measures to rebuild the fishery must be added to the FMP. These conservation measures are contained in the snow crab rebuilding plan.

NMFS determined that Amendment 14 to the FMP is consistent with the Magnuson-Stevens Act and other applicable laws and approved Amendment 14 on December 28, 2000. Additional information on this action is contained in the September 29, 2000, notice of availability (65 FR 58501).

No regulatory changes are necessary to implement this FMP amendment.