Stock Assessments

Guidance and Oversight

Coordinating the efforts of the Atlantic coastal states in the development and implementation of interstate fisheries management programs is the Commission’s primary role, with stock assessments forming the basis of management programs. The Commission assesses fish stocks to determine their status, to evaluate how stocks have been affected by management actions, and to forecast future stock conditions under potential new management actions. In fisheries, determining stock status means estimating the size of the population, either in numbers of fish (abundance) or the total weight of the population (biomass), and the rate at which fish are removed by fishing (fishing mortality rate). Population size and fishing mortality rate are compared to reference points that define sustainable conditions to determine whether the stock is overfished (the population size is too low) or overfishing is occurring (the fishing mortality rate is too high).

The Commission conducts stock assessments on Commission-managed species in order to determine the health and status of the fish stocks and to provide scientific advice to fisheries managers. The Commission also works closely with NOAA (National Oceanic and Atmospheric Administration) Fisheries Science Centers and Regional Fishery Management Councils on the assessments for jointly or cooperatively managed species, such as Atlantic herring, summer flounder, and Spanish mackerel.

Generally, the Commission conducts two types of stock assessments: (1) a benchmark stock assessment and (2) a stock assessment update. A benchmark stock assessment is a full analysis and review of the stock condition, focusing on the consideration of new data sources and newer or improved assessment models. This assessment is generally conducted every three to five years and undergoes a formal peer review by a panel of independent fisheries scientists (peer-reviewed stock assessment). A stock assessment update incorporates data from the most recent years into the peer-reviewed assessment model to determine current stock status (abundance and overfishing level).

Peer Review

In order to ensure the quality and credibility of its stock assessments for management use, the Commission oversees a formal external peer review process to evaluate all benchmark assessments to determine whether the data and methods used to produce the assessment are scientifically sound and appropriate for management use. The Commission’s stock assessment peer review process also includes regional programs following similar procedures coordinated by NOAA Fisheries - the Northeast Stock Assessment Workshop/Stock Assessment Review Committee (SAW/SARC) and the SouthEast Data and Assessment Review (SEDAR).

Northeast Region Coordinating Council

Within the Northeast region the Commission, along with NOAA Fisheries Greater Atlantic Regional Fisheries Office, the Mid-Atlantic Fishery Management Council, the New England Fishery Management Council, and NOAA Fisheries Northeast Fisheries Science Center, also participates as a member of the Northeast Region Coordinating Council (NRCC). Formed in 2001, the NRCC’s mission is to “prioritize, communicate, and coordinate fisheries scientific and management resources through in-person meetings that include federal, state, council, and commission managers and scientists of the Greater Atlantic Region of the United States.”

In 2019, the NRCC established a new and more collaborative fishery stock assessment process with assessments scheduled years in advance to allow for better planning. The process involves two types of assessments – management track and research track. Management track assessments provide routine, scheduled, and updated advice to directly inform management actions. These assessments are designed to be simple, quick, efficient, and flexible; and able to incorporate new information on a regular cycle. Management track assessments ensure that stock status is updated on a regular and predictable basis. Research track assessments are complex scientific efforts that are designed to be carried out over several years. They can: (1) focus on research topics or on one or more individual stocks; (2) evaluate an issue or new model that could apply to many stocks; and/or consider extensive changes in data, model, or stock structure. Both management and research track assessments are generally conducted though SAW/SARC, with the exception of Commission-only managed species, such as Atlantic striped bass and American lobster. For more information on the NRCC process, visit https://www.nefmc.org/committees/northeast-regional-coordinating-council-nrcc.

Training

State and federal scientists attend an ASMFC Stock Assessment Training Workshop. Photo ©ASMFC.

The Commission conducts workshops and distributes educational materials to provide hands-on training to state fishery biologists in quantitative population dynamics and stock assessment models. Advanced workshops have also been conducted for those state and federal stock assessment scientists in order to facilitate an exchange of information and provide state-of-the-art training in uncertainty principles and modeling techniques.

For managers and stakeholders, a Guide to Fisheries Science and Stock Assessments provides an introduction to the concepts and methods that form the basis of stock assessments. Layman educational seminars are also periodically conducted to increase understanding of stock assessment methods and applications.