Gary A. Tilyou

Evaluation of Unattended Yo-yos and Triggers

The establishment of black bass (Micropterus sp.) size restrictions on some Louisiana lakes prompted a study to determine the catch and mortality rates of unattended yo-yos and triggers. From 15 November 1991 to 11 March 1992 gears were fished in close proximity in 5 impoundments a total of 825 nights per gear. The catch rate for all species was 0.168 fish/yo-yo night and 0.080 fish/trigger night. Largemouth bass (M. salmoides) catch rates were 0.005 fish/yo-yo night and 0.002 fish/trigger night. Mortality of all fish caught on unattended yo-yos and unattended triggers was 61% and 7%,...


Potential Caviar Fishery Impacts on Louisiana Bowfin Populations

In recent years, a small scale bowfin (Amia calva) roe fishery in Louisiana has increased in both volume and value. To initiate an evaluation on the impacts of this fishery on bowfin populations, 3 study areas were selected to represent various ecosystems inhabited by bowfin. It was not possible to relate growth, size, and sexual maturity with age based on otolith samples. Length-frequency data suggested that 9-month-old fish ranged from 225-400 mm and 21-month-old bowfin may grow to 525 mm. Gonadosomatic indices showed a constant increase through February, and all females observed had...