| Abstrakt: |
AbstractThe purpose of this study was to assess initial and delayed mortality of spotted seatrout Cynoscion nebulosus captured during live-release tournaments. Additionally, we examined spotted seatrout mortality as a function of season and anatomical hooking location. We assessed tournament-related mortality at 10 live-release fishing tournaments held in four Texas bays—Galveston, Matagorda, Aransas, and Upper Laguna Madre—from February 2004 to April 2006. Combined overall mean mortality was 22.9%, mean initial mortality (percent of dead fish brought to weigh-in) was 10.4%, mean delayed mortality (percent of fish that died in tournament holding tanks) was 14.1%, and delayed short-term mortality (percent of fish that died during a 14-d observation period in laboratory tanks) was 1.9%. To assess seasonal mortality, we examined a total of 364 spotted seatrout captured by hook and line from July 2004 to June 2005 using replicated 3.5-m3field enclosures for 72 h. Overall mortality for the seasonal study was 6%. Mortality rates were higher during spring (9%) and summer (10%) than during fall or winter (both 0%). Tournament organizers should avoid scheduling events during late spring and summer, when seasonal mortalities are the highest. To assess mortality as a function of anatomical hooking location, we examined a total of 479 spotted seatrout held in field enclosures after capture. We assigned hooking locations to four body regions: mouth, gills, esophagus, and external. Overall mortality for the anatomical hooking location study was 19%. Mortalities were higher for fish hooked in the esophagus (95%) and gills (75%) than for fish hooked in the mouth (10%) and externally (8%). Our results suggest that spotted seatrout mortality during live-release tournaments exceeds that observed under normal catch-and-release fishing practices and that posttournament delayed mortality is low. Anatomical hooking location is a major factor influencing mortality, but under normal fishing practices only about 12% of fish are hooked in locations that consistently cause mortality. |
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