Fisheries Assessment and Modeling Research on California Salmon and Groundfish

Our team performs stock assessments and conducts research focused on improving fisheries management.

A program of the Southwest Fisheries Science Center’s Fisheries Ecology Division.

The Fisheries Assessment Modeling Team studies fishery dynamics, assessment, and ecology, providing scientific support to salmon and groundfish fishery management. Research themes include population dynamics, demography, statistical methods for natural resource management, and stock assessment. Team members participate in a variety of working groups, including those focused on hatchery review, stock assessment improvement, amendment of fishery management plans, and genetic stock identification.

Our Research

Groundfish Stock Assessments and Fishery Management Support

Stock assessment models integrate demographic information (age and length structure of a population) with fisheries catches and abundance indicators from surveys to estimate sustainable harvest levels for recreational and commercial fisheries. These models form the scientific basis for fishery management by NOAA Fisheries and the Pacific Fishery Management Council (PFMC).

Our researchers have contributed significantly to stock assessment activities for West Coast groundfish fisheries, leading investigations and assessments for many species including cowcod, bocaccio, chilipepper rockfish, widow rockfish, gopher/black and yellow rockfish, blue/deacon rockfish, and California scorpionfish.

Other efforts supporting these stock assessment models include:

  • Studying the reproductive ecology of target species
  • Developing age data using annual growth rings in otoliths (ear stones)
  • Developing methods to improve catch estimation in mixed stock fisheries

We also contribute to the development of novel analytical methods to evaluate stock abundance and productivity, and support a number of advisory bodies including the PFMC Scientific and Statistical Committee, the PFMC Groundfish Management Team, and the Recreational Fisheries Information Network (RecFIN) technical and statistical committees.

Salmonid Stock Assessment

We have a long history of conducting salmon stock assessments through the PFMC Salmon Technical Team, contributing to the annual season setting process for commercial, recreational, and Tribal salmon fisheries.

Salmon Assessment Model Improvement

An important focus of our team is improving scientific advice provided to fishery managers by developing better methods for estimating abundance, fishing mortality rates, and other metrics used to assess stock status. We have created new assessment and forecasting tools for Sacramento River fall Chinook, the most important target stock for California and Oregon ocean salmon fisheries, and Sacramento River winter Chinook, an endangered population. Additionally, we engage in research aimed at improving the accuracy of salmon abundance forecasts, which are an integral part of the annual management process.

Estimation of Salmonid Distribution

We are working to refine and extend models describing where different salmon stocks occur in the ocean, and how these distributions change over time and in response to environmental conditions. Understanding ocean distributions of salmon stocks are key to designing fisheries in ways that provide opportunities to harvest abundant stocks while reducing impacts on weaker stocks, and understanding ecosystem roles of salmon such as their contribution to the diets of Southern Resident Killer Whales and other marine predators.

Salmon Life History

We perform research aimed at better characterizing and predicting the life history characteristics of salmon, including their rates of mortality, maturation, and straying. These rates are important in modeling the population dynamics of salmon under varying environmental conditions, for forecasting abundance to inform management, and for identifying appropriate fishery exploitation rates.

Our Service

Members of the team conduct and contribute to stock assessments through the Pacific Fishery Management Council (PFMC). We also serve on the PFMC Scientific and Statistical Committee, ensuring that sound science guides fishery management decisions. Team members regularly contribute to Endangered Species Act (ESA) Biological Review Teams and provide scientific advice in support of fishery consultations for ESA-listed salmon populations.

Our Team

Team Leader: Mike O'Farrell