M. M. Hale

Estimating Annual Game Fish Bycatch in Commercial Fishing Devices from Harvest Data

A major concern in managing commercial fisheries is the potential effect on game fish populations. The objective of this study was to design a model to determine annual game fish bycatch in hoop nets, wire traps, and pound nets utilized in the 51. Johns River, Florida, commercial catfish fishery. Annual bycatch was estimated with a model based on previous estimates of annual catfish harvest, catfish-to-game fish ratios, mean weight of catfish harvested and percentage composition of catfish harvested by each gear type. Hoop nets captured an estimated 435,635 game fish annually with 46,697...


Growth History of Black Crappie Spawned 1980, St. Johns River, Florida

Growth rates for the 1980 year class of black crappie were determined from samples collected in the St. Johns River, Florida, 1981 through 1987. Actual mean lengths of groups of black crappie aged by otolith evaluation were compared to back calculated lengths from otoliths of black crappie collected each year. Differences in actual and back calculated lengths for black crappie collected were not significant (P > 0.05). Coefficient of determination values (r2) dropped rapidly as differential growth rates increased. Overall, back calculated lengths for age I and II black crappie increased...


Evaluation of Wire Catfish Traps for Commercial Fishing in Central Florida Lakes

Two types of commercial wire catfish traps were fished in lakes Dora and Eustis between January and May 1984. Catches at shoreline and offshore fishing sites were evaluated for both trap types. Door throat traps harvested 4.1 catfish, 0.6 game fish, and 0.1 non-game fish per trap day. Open throat traps harvested 0.8 catfish, 0.6 game fish, and 0.2 non-game fish per day. Door throat traps were 5.7 times more efficient at harvesting catfish than open throat traps. Overall, shoreline fishing sites yielded more fish (catfish, game fish, and non-game fish) than offshore sites. Initial mortality...


Bias from Age-grouping Black Crappie by Length-frequency as Compared to Otolith Aging

Eighteen hundred and thirty-four black crappie (Pomoxis nigromaculatus) were collected from the St. Johns River, Florida, in late winter and early spring, 1982 to 1985. Differences in numbers and growth rates of males and females collected were not significant (P > 0.05). Fish were separated into age groups using length-frequency distributions and by counting annuli on otoliths. Only 2 distinct age groups were discernible by length-frequency analysis, whereas 6 to 8 groups were identified by otolith aging. Mean lengths of age groups obtained from lengthfrequency were overestimated 3 of...


Aging of Three Species of Florida Catfish Utilizing Three Pectoral Spine Sites and Otoliths

Twenty-one brown bullhead (Ictalurus nebulosus), 25 channel catfish (I. punctatus) and 25 white catfish (I. catus) collected by fish trap were aged by counting annuli from the articulating process (AP), basal recess (BR) and mid-spine (MS) sections of pectoral spines. Five large channel catfish collected from hoop nets were also aged using spine techniques. Attempts were also made to age catfish by counting opaque bands or checks from whole sagittal otoliths and otolith longitudinal and cross sections. Annuli were visible in all pectoral spine sections. Fish older than 3 years showed some...