Fishery Stock Assessment Models and Their Application to Sharks

Selectivity: theory, estimation, and application in fishery stock assessment models

Accounting for Spatial Population Structure in Stock Assessment: Past, Present, and Future*

Stock identification has been an important prerequisite for stock assessment throughout its history. The earliest evaluations of recruitment variability recognized that understanding the spatial scale of a fishery resource is essential for studying population dynamics. A paradigm of stock structure was based on closed migration circuits and geographic variation of phenotypic traits and formed a...

Stock assessment methods used for cephalopod

Cephalopods are of increasing importance as a fishery resource and many species are taken in directed and bycatch fisheries around the world. Owing to the short life-cycles and variable growth rates of most cephalopods, stocks may be highly volatile, both highly susceptible to recruitment overfishing and, conversely, capable of rapid recovery. Many species have protracted spawning seasons so th...

Genetic identification of sharks in the U.S. Atlantic large coastal shark fishery*

The U.S. Atlantic large coastal shark fishery grew rapidly during the 1980s when commercial landings increased from 135 metric tons (t) in 1979 to a high of 7122 t in 1989 (NMFS, 1993). In 1993, a quota of 2750 t was established; in 1997 this quota was halved to 1375 t in order to rebuild depleted shark stocks. This fishery targets several species of sharks that are valued for fins (exported to...

Toward Species-specific Catch and Cpue Time Series for Sharks Caught by the Japanese Longline Fishery in the Atlantic Ocean

This document introduces problems associated with shark catch data and CPUE indices using the Japanese longline fishery in the Atlantic as an example. A number of methods for addressing issues of under-reporting, short time series, and undifferentiated shark species are introduced including reporting rate filtering, comparison to observer datasets, covariate analysis, meta-analysis and tradebas...