Groundfish Subcommittee of the Scientific and Statistical Committee Online Workshop

The Groundfish Subcommittee of the Pacific Fishery Management Council’s (Pacific Council’s) Scientific and Statistical Committee (SSC) will hold a workshop to develop methods for constructing abundance indices based on hook-and-line (H&L) surveys June 21-23 from 8 a.m.- to 5 p.m. each day.

 

“NMFS does an annual H&L survey for rockfish in the Southern California Bight,” said John DeVore, a NOAA affiliate in an email from May 11.  “Three CPFVs (aka recreational fishing charter boats) and their skippers and crew are hired each year to fish select sites (nearshore and shelf reefs) in a systematic fashion.  Onboard scientists record catch by species, physical conditions on the water, and collect biological samples (lengths. otoliths or ear bones used to age the fish, gonads for determining sex and maturity, etc.).  These data are used in stock assessments.”

 

The SSC Groundfish Subcommittee also reviewed the Species Distribution Model in Template Model Builder. The workshop and methodology review meeting are open to the public.

 

A groundfish stock assessment is a statistical analysis of data from fisheries, surveys, and oceanographic measurements, designed to inform the PFMC and NOAA on the abundance, productivity, and status (how healthy the population is with respect to theoretical limits of target abundance to maximize fish production) of a fish population.  Estimates of all these life history attributes rely on construction of one or more relative abundance indices, which are constructed using catch-per-unit effort (CPUE) data of the species from surveys or, in some cases, from fisheries.

 

The SSC Groundfish Subcommittee’s meeting aims to develop methods and the best practices for constructing abundance indications based on hook-and-line surveys in a workshop.

 

Recommendations of SSC Groundfish Subcommittee members will inform the 2023 Accepted Practices Guidelines for Stock Assessments, which is a compilation of guidelines for groundfish stock assessment scientists. In addition, the SSC Groundfish Subcommittee will review the Species Distribution Model in Template Model Builder (sdmTMB).

 

“The Species Distribution Model in Template Model Builder is a statistical model used to develop relative abundance indices used in stock assessments that better represent the spatial distribution of the species,” said DeVore. “This website provides a technical description of sdmTMB.  It is designed for scientists who use the model and may not be all that helpful without a strong statistics background.”

 

The sdmTMB model is proposed for developing relative biomass indices in future groundfish stock assessments. The SSC Groundfish Subcommittee report of workshop and methodology review findings and recommendations will be provided to the Pacific Council and the SSC at the November 2022 Pacific Council meeting.

 

June 21 Agenda:

1. Administrative Matters
2. Roll Call, Introductions, Announcements, etc.
3. Review and Approve Agenda and Workshop Scope

 

1. California Collaborative Fishery Research Program (CCFRP) Hook and Line Survey
2. Survey design and operations
3. Current analytical methods
4. Vermilion/Sunset Rockfish Assessment Case Study
5. CCFRP specific discussion

 

1. Northwest Fisheries Science Center (NWFSC) Hook and Line Survey
2. Survey design and operations
3. Current analytical methods
4. Cowcod Rockfish Assessment Case Study
5. Vermilion/Sunset Rockfish Assessment Case Study
6. Gear saturation and interspecies interactions
7. Survival analysis
8. NWFSC H&L specific discussion
9. Discussion of common H&L survey issues
10. Identify clarifying requests, continuing discussion items, and wrap-up

 

June 22 Agenda:

1. Methodology Review Introduction
2. Roll Call, Introductions, Announcements, etc.
3. Review Agenda and Review Scope

 

1. Species Distribution Model in Template Model Builder (sdmTMB) Methodology Review
2. sdmTMB Overview
3. Comparison of the sdmTMB and the Vector Autoregressive Spatial Temporal Models
4. Discussion

 

1. Hook and Line Surveys, Continued
2. Review Clarifying Requests
3. Discussion Topics from Day 1

 

1. Administrative Matters, Continued
2. Review Clarifying Requests

 

June 23 Agenda:

1. Identify Accepted Practices and Future Research Needs
2. Outstanding Items from Days 1 and 2
3. Presentations / Discussions
4. Administrative Matters, Continued
5. Workshop and Methodology Review Meeting Report Drafting