Stock Status Categories and Definitions
An abundance index is a measure of changes in population size over time. It is usually represented as the number of individuals caught per unit of effort sample (e.g., catch per tow).
Stocks designated as CONCERN are those stocks that exhibit increased effort, declining landings, truncated age distribution, or are negatively impacted by biotic and/or abiotic factors that cannot be controlled (example: water quality, habitat loss, disease, life history, predation, etc). Stocks with or without an approved stock assessment or FMP but are exhibiting declining trends may be classified as CONCERN. [Overfishing; Not Overfished]* Stocks whose assessments have unreliable benchmarks may also be classified as CONCERN (Example: Overfishing can not be determined)
Dependent data are collected directly from commercial or recreational fisheries. This can be done through the reported landings, dock-side sampling, or creel surveys
Depleted stocks are those stocks where the spawning stock abundance is below a predetermined threshold or where low stock abundance precludes an active fishery. Factors that can contribute to DEPLETED status include but are not limited to fishing, predation, competition, water quality, habitat loss, recruitment variability, disease, or a combination of these factors. Determination is based on approved DMF, ASMFC, and/or regional Council FMPs and/or stock assessments. [Overfishing; Overfished]*
Species designated as DEPLETED would be priority candidates for FMP development.
Independent data are collected from sources other than fishing activity using a statistically designed sampling method. These data are usually obtained through federal, state, or academic research program
Recovering stocks are those stocks that show marked and consistent improvement in the criteria listed for a VIABLE stock. A RECOVERING species may still be depleted but would be defined as one that, under a current plan, shows measurable and consistent improvement but has not yet reached the target(s) of a specific FMP. [No Overfishing; Overfished]*
Stocks for which insufficient data are available to determine trends in effort, landings, age distribution, recruitment, etc. are classified as UNKNOWN. Many stocks that have been designated as UNKNOWN have been picked up in DMF sampling programs that may result in sufficient data to designate a status in the future.
Viable stocks exhibit stable or increasing trends in average length and weight, catch per unit effort, spawning stock biomass, juvenile abundance indexes based on historical averages, stable age structure that includes representatives of the older age classes, and stable or declining trends in fishing mortality. Stocks deemed recovered by a Division of Marine Fisheries (DMF), Atlantic States Marine Fisheries Commission (ASMFC), or regional Council fishery management plan (FMP) would be considered VIABLE. A stock is considered recovered when it has reached the target(s) for sustainable harvest, spawning stock biomass, spawning potential ratio, fishing mortality, size/age structure, or any other biological target required in an approved DMF, ASMFC and/or regional Council FMP. [No Overfishing; Not Overfished]*
N.C. Division of Marine Fisheries • 3441 Arendell Street • Morehead City, NC 28557 • 252-726-7021 or 800-682-2632