"Alaska Groundfish Research"

In 2006, the Gulf of Alaska rex sole (Glyptocephalus zachirus) stock was moved to a biennial stock assessment schedule to coincide with the expected receipt of new survey data. A discussion at the September 2006 Groundfish Plan Team meetings concluded the following two important points for updating information in off-year assessments: 1) Anytime the assessment model is re-run and presented in the SAFE Report, a full assessment document must be produced. 2) The single-species projection model may be re-run using new fishery catch data without rerunning the assessment model.

Rockfish are assessed on a biennial stock assessment schedule to coincide with the availability of new survey data. For Gulf of Alaska rockfish in on-cycle (odd) years, we present a full stock assessment document with updated assessment and projection model results. However, due to the 2013 government shutdown, we do not present alternative model configurations in this year’s assessment. Additionally, some sections may not have been fully updated from the 2011 assessment document. We use a statistical age-structured model as the primary assessment tool for Gulf of Alaska Pacific ocean perch which qualifies as a Tier 3 stock. This assessment consists of a population model, which uses survey and fishery data to generate a historical time series of population estimates, and a projection model, which uses results from the population model to predict future population estimates and recommended harvest levels. For this on-cycle year, we update the 2011 assessment model estimates with new data collected since the last full assessment.

Pacific cod (Gadus macrocephalus) is a transoceanic species, occurring at depths from shoreline to 500 m. The southern limit of the species’ distribution is about 34° N latitude, with a northern limit of about 63° N latitude. Pacific cod is distributed widely over Gulf of Alaska (GOA), as well as the eastern Bering Sea (EBS) and the Aleutian Islands (AI) area. Tagging studies (e.g., Shimada and Kimura 1994) have demonstrated significant migration both within and between the EBS, AI, and GOA. Recent research indicates the existence of discrete stocks in the EBS and AI (Canino et al. 2005, Cunningham et al. 2009, Canino et al. 2010, Spies 2012). Pacific cod is not known to exhibit any special life history characteristics that would require it to be assessed or managed differently from other groundfish stocks in the GOA. The Pacific cod stock in the GOA is managed as one stock.

Two issues were put forth by the Gulf of Alaska (GOA) plan team to be examined by the Other Rockfish assessment authors: 1) examine the catch and survey data for the DSR (demersal shelf rockfish complex) species outside of the Southeast management area and investigate whether a separate OFL and ABC can be established for DSR species outside of the Southeast management area; and 2) examine the fishery catch records in more detail to determine which areas, species and target fisheries are contributing to the higher catch levels of harlequin rockfish. This document details responses to both issues.

Through 2010, octopuses were managed as part of the “other species” complex, with catch reported only in the aggregate along with sharks, squids, and sculpins. Due to increasing market interest, retention of some other species complex members is increasing. Beginning in 2011, the GOA fisheries management plan has been amended to provide separate management for sharks, sculpins, and octopus. In compliance with the reauthorized Magnuson-Stevens act, each group will have its own annual catch limit. Catch limits for octopus for 2011 - 2013 were set based on using the average of the last 3 surveys as a minimum biomass estimate. For 2014- 2015 two methods of estimating minimum biomass are presented: the average of three surveys or the random effects model applied to survey biomass estimates. Both methods give similar results.

Due to the government shut-down in October 2013, stock assessments for an abbreviated suite of model runs are required only for Steller sea lion prey species (walleye pollock, Pacific cod, Bering Sea/Aleutian Islands Atka mackerel), and species where a conservation concern has been noted. For all other Tier 1-3 stocks, updated projections from last year using 2013 catch data are required at a minimum. Results will be presented in executive summaries using the “off-year” format for stocks on biennial assessment cycles.

Rockfish are assessed on a biennial stock assessment schedule to coincide with the availability of new survey data. For Gulf of Alaska rockfish in on-cycle (odd) years, we present a full stock assessment document with updated assessment and projection model results. However, due to the 2013 government shutdown, we do not present alternative model configurations in this year’s assessment. Additionally, some sections may not have been fully updated from the 2011 assessment document. As in 2011, the general model structure for GOA northern rockfish is a separable age-structured model as used for Gulf of Alaska Pacific ocean perch, dusky rockfish, and rougheye/blackspotted rockfish. This consists of an assessment model, which uses survey and fishery data to generate a historical time series of population estimates, and a projection model, which uses results from the assessment model to predict future population estimates and recommended harvest levels. GOA rockfish are assessed on a biennial stock assessment schedule to coincide with new survey data. For Gulf of Alaska rockfish in alternate (even) years, we present only an executive summary to recommend harvest levels for the next (odd) year. For this on-cycle year, we update the 2011 assessment model with new data acquired since 2011.

Flathead sole (Hippoglossoides elassodon) are distributed from northern California, off Point Reyes, northward along the west coast of North America and throughout the GOA and the BS, the Kuril Islands, and possibly the Okhotsk Sea (Hart 1973). They occur primarily on mixed mud and sand bottoms (Norcross et al. 1997, McConnaughey and Smith 2000) in depths < 300 m (Stark and Clausen 1995). The flathead sole distribution overlaps with the similar-appearing Bering flounder (Hippoglossoides robustus) in the northern half of the Bering Sea and the Sea of Okhotsk (Hart 1973), but not in the Gulf of Alaska.

Rockfish are assessed on a biennial stock assessment schedule to coincide with the availability of new survey data. For Gulf of Alaska rockfish in on-cycle (odd) years, we present a full stock assessment document with updated assessment and projection model results. However, due to the 2013 government shutdown, we do not present alternative model configurations in this year’s assessment. Additionally, some sections may not have been fully updated from the 2011 assessment document. We use a statistical age-structured model as the primary assessment tool for Gulf of Alaska dusky rockfish which qualifies as a Tier 3 stock. This assessment consists of a population model, which uses survey and fishery data to generate a historical time series of population estimates, and a projection model, which uses results from the population model to predict future population estimates and recommended harvest levels. For this on-cycle year, we update the 2011 assessment model estimates with new data collected since the last full assessment.

2013 Assessment of the Demersal Shelf Rockfish Stock Complex in the Southeast Outside District of the Gulf of the Alaska