Evaluation of Mature Size for Tanner Crab from the Kodiak District Large-mesh Trawl Survey, 1996-2019
Evaluation of Mature Size for Tanner Crab from the Kodiak District Large-mesh Trawl Survey, 1996-2019

Author: Michael Knutson

Publisher:

Published: 2022

Total Pages: 16

ISBN-13:

DOWNLOAD EBOOK

Size at male maturity is a valuable metric for sustainable management of many species. It is used to protect the reproductive viability of stocks and is often incorporated directly into commercial fishing regulations, as is the case with Tanner crab (Chionoecetes bairdi) in the Kodiak District. This metric had been estimated previously for this stock, but size at maturity can change with environmental conditions or increases in harvest pressure. This study utilized the allometric ratio between chela height and carapace width, a widely accepted nonlethal method, to classify maturity status using two different approaches. A logistic regression model was then developed to estimate the size at 50% maturity. The traditional method of classifying crab utilizing a single allometric ratio for the entire range of carapace widths estimated a mature size of 110.78 mm, within the range of previously estimated mature sizes. The recently developed method of classifying mature status using a ratio that is allowed to vary across the distribution of carapace widths estimated a slightly lower size at maturity at 109.59 mm; however, this method performs better at assigning maturity status to crab at the upper and lower end of the carapace width range. There does not appear to be compelling evidence that the current regulatory size at maturity (114 mm) needs to be adjusted because it still accurately represents the size at 50% maturity for this stock.

A Bottom Trawl Survey for Tanner Crab in Prince William Sound, 2020
A Bottom Trawl Survey for Tanner Crab in Prince William Sound, 2020

Author: Wyatt J. Rhea-Fournier

Publisher:

Published: 2022

Total Pages: 0

ISBN-13:

DOWNLOAD EBOOK

A large-mesh bottom trawl survey of Tanner crab Chionoecetes bairdi was conducted in 2020 in the Prince William Sound Area (PWSA; Registration Area E) with the objective of establishing protocols for generating Tanner crab abundance estimates for a newly established survey area. New survey areas in PWSA were developed to assess new commercial fishery districts that were proposed at the 2021 Alaska Board of Fisheries meeting. Proposed fishery districts encompass historical fishing areas and areas fished in the recent commissioner’s permit fishery. Methodology from the historical PWSA trawl survey was applied to develop new trawl stations with the goal of calculating catch per unit effort (CPUE) to estimate abundance of historical legal size and legal-size male Tanner crab in the surveyed area. The 2020 survey produced a CPUE for male Tanner crab that were of the historical legal size of 28.4 crab per nmi2, which was the third lowest observation for any Alaska Department of Fish and Game trawl survey in the PWSA. The estimated abundance of historical legal-size male Tanner crab was 8,214 crab in the survey area, and the estimated abundance for legal-size male Tanner crab was 35,920 crab in the survey area.

Operational Plan
Operational Plan

Author: Wyatt J. Rhea-Fournier

Publisher:

Published: 2020

Total Pages: 31

ISBN-13:

DOWNLOAD EBOOK

The primary objective of the 2020 Tanner crab, Chionoecetes bairdi, large-mesh bottom trawl survey is to develop a new survey area in the inside waters of Prince William Sound. Methodology from the historical trawl survey will be applied to develop new trawl stations with the goal of generating abundance estimates for the surveyed area. Abundance estimates will be generated for current and historical legal-size male Tanner crab for management purposes. Male Tanner crab biological measurements will be collected for estimating size at morphological maturity and mature male crab will be tagged for observing season movement.

Prevalence of Bitter Crab Syndrome and Bacterial Infection of Tanner Crab, Chionoecetes Bairdi, in the Kodiak, Chignik, South Peninsula and Eastern Aleutian Management Areas
Prevalence of Bitter Crab Syndrome and Bacterial Infection of Tanner Crab, Chionoecetes Bairdi, in the Kodiak, Chignik, South Peninsula and Eastern Aleutian Management Areas

Author: Thomas W. Pearson

Publisher:

Published: 1992

Total Pages: 72

ISBN-13:

DOWNLOAD EBOOK

Reports the results the analysis of hemolymph samples obtained from southern Tanner crabs taken in ADF&G's 1990 bottom trawl survey in the Kodiak Island, Chignik, South Alaska Peninsula and Eastern Aleutian Island management districts.

Large-mesh Bottom Trawl Survey of Crab and Groundfish: Kodiak, Chignik, South Peninsula, and Eastern Aleutian Management Districts, 2021
Large-mesh Bottom Trawl Survey of Crab and Groundfish: Kodiak, Chignik, South Peninsula, and Eastern Aleutian Management Districts, 2021

Author: Kally Spalinger

Publisher:

Published: 2022

Total Pages: 153

ISBN-13:

DOWNLOAD EBOOK

This report summarizes results from the large-mesh bottom trawl survey that took place June through September 2021 to assess crab and groundfish resources in the Kodiak, Chignik, South Peninsula, and Eastern Aleutian Tanner crab Chionoecetes bairdi management Districts. A total of 337 trawl hauls were conducted to assess relative abundance and condition of commercially important crabs, as well as spatial distribution, species composition, size frequency, and catch per unit effort of commercially important groundfish. Survey estimates indicated that mature and legal male Tanner crab abundances were sufficient to support commercial fisheries in 3 sections of the Kodiak District, the Chignik District, and both sections of the South Peninsula District. Red king crab Paralithodes camtschaticus abundance estimates in each of the surveyed management areas remain too low to consider opening a red king crab commercial fishery. Arrowtooth flounder Atheresthes stomias, flathead sole Hippoglossoides elassodon, walleye pollock Gadus chalcogrammus, and yellowfin sole Limanda aspera, were the dominant groundfish captured during the survey. report summarizes results from the large-mesh bottom trawl survey that took place June through September 2020 to assess crab and groundfish resources in the Kodiak, Chignik, and South Peninsula Tanner crab Chionoecetes bairdi management districts. A total of 348 trawl hauls were conducted to assess relative abundance and condition of commercially important crabs, as well as spatial distribution, species composition, size frequency, and catch per unit effort of commercially important groundfish. Survey estimates indicated that mature and legal male Tanner crab abundances were not sufficient to support commercial fisheries in the districts. Red king crab Paralithodes camtschaticus abundance estimates in each of the surveyed management areas remain too low to consider opening a red king crab commercial fishery. Arrowtooth flounder Atheresthes stomias, flathead sole Hippoglossoides elassodon, walleye pollock Gadus chalcogrammus, and yellowfin sole Limanda aspera, were the dominant groundfish captured during the survey.