APPENDIX C Glossary
Acceptable biological catch (ABC)—
a preliminary description of acceptable harvest (or range of harvests) for a given stock or stock complex. Its derivation focuses on the status and dynamics of the stock, environmental conditions, other ecological factors, and prevailing technological characteristics of the fishery. The fishing mortality rate used to calculate ABC is constrained to be lower than rates associated with overfishing.
Catch per unit effort (CPUE)—
an index showing the ratio of a catch of fish, in numbers or in weight, and a standard measure of the fishing effort expended to catch them.
Maximum sustainable yield (MSY)—
the largest average catch or yield that can be continuously taken from a stock under existing environmental conditions.
Metapopulation—
a set of local populations in some larger area, where migration between patches is possible (Hanski and Simberloff, 1997).
Odobenids—
one of the three families of pinnipeds. This family is primarily made up of walruses.
Otariids—
one of the three families of pinnipeds. This family is primarily made up of sea lions and fur seals.
Phocids—
one of the three families of pinnipeds. This family is primarily made up of true seals.
Recruitment overfishing—
the rate of fishing above which recruitment to the exploitable stock becomes significantly reduced. This is characterized by a greatly reduced spawning stock, a decreasing proportion of older fish in the catch, and generally very low recruitment year after year.
Spawning stock biomass (SSB)—
the total weight of all sexually mature fish in the population. This quantity depends on year-class abundance, the exploitation pattern, the rate of growth, fishing and natural mortality rates, the onset of sexual maturity, and environmental conditions.
Total allowable catch (TAC)—
an annually determined catch that is species specific and based on consideration of maximum sustainable yield, equilibrium yield, and optimum yield for the groundfish complex as a whole.
