Comparison of life history parameters for landed and discarded fish captured off the southeastern United States
Commercial fisheries that are managed with minimum size limits protect small fish of all ages and may affect size-selective mortality by the differential removal of fast growing fish. This differential removal may decrease the average size at age, maturation, or sexual transition of the exploited population. When fishery-independent data arenot available, a comparison of life history parameters of landed with those of discarded fish (by regulation) willindicate if differential mortality is occurring with the capture of young but large fish (fast growing phenotypes).Indications of this differential size-selective mortality would include the following: the discarded portion of the target fish would have similar age ranges but smaller sizes at age, maturation, and sexual transition as that of landed fish. We examined three species with minimum size limits but different exploitation histories. The known heavily exploited species (Rhomboplites aurorubens [vermilion snapper] and Pagrus pagrus [red porgy]) show signs of thisdifferential mortality. Their landed catch includes many young, large fish, whereas discarded fish had a similar age range and mean ages but smaller sizes at age than the landedfish. The unknown exploited species, Mycteroperca phenax (scamp), showed no signs of differential mortality dueto size-selective fishing. Landed catch consisted of old, large fish and discarded scamp had little overlap in age ranges, had significantly different mean ages, and only small differences in size at age when compared to comparabledata for landed fish.
| Main Authors: | , , |
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| Format: | article biblioteca |
| Language: | English |
| Published: |
2011
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| Subjects: | Biology, Ecology, Fisheries, |
| Online Access: | http://hdl.handle.net/1834/25358 |
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