Improving stock assessments through maturity and age validation analyses for four data-poor rockfishes in the Aleutian Islands and Gulf of Alaska, 2009-2016

• Main Authors: Helser, Thomas, TenBrink, Todd, Spencer, Paul, Conrath, Christina
• Format: Dataset
• Language: English
• Published: Axiom Data Science 2020
• Subjects: Bering Sea; Gulf of Alaska; Pacific; Alaska; Aleutian Islands
• Online Access: https://dx.doi.org/10.24431/rw1k43v; https://search.dataone.org/#view/10.24431/rw1k43v

Four commercially important data-poor (currently designated as Tier 5 by the North Pacific Fishery Management Council) species were targeted for research: shortspine thornyhead (Sebastolobus alascanus), shortraker rockfish (Sebastes borealis), harlequin rockfish (S. variegatus), and redstripe rockfish (S. proriger). Research was conducted on each of these species in both the Bering Sea-Aleutian Islands (BSAI) and Gulf of Alaska (GOA) management areas. This research focused on three primary components: reproductive biology with special emphasis on maturity, age validation, and age error modeling. The maturity component involved field collections in the AI and GOA using both fisheries-independent and -dependent sampling platforms. Contemporary samples from 2014-2016 were used in the analyses, as well as previous collections from 2009-2010. The analyses resulted in female length and age at maturity estimates (ogives). Variables in the dataset include specimen information such as length, weight and age, location, year, month of collection, and maturity status (0=immature; 1=mature). These new estimates would potentially support upward movement from Tier 5 management (i.e. moving to Tier 4) by providing managers with increased information to report separate fishing reference points. Age validation analyses were based on the bomb-produced radiocarbon C-14 method. Variables in the dataset include specimen information such as length, weight, average age based on multiple ages, sex, location, year (cruise), whole otolith weight, its core weight, and C-14 material measured with 1 standard deviation. These validation results would help in potentially supporting upward movement from Tier 5 management (i.e. moving to Tier 4) by providing managers with increased information to report separate fishing reference points. This dataset was generated as part of NPRB project 1401.