Robert K. Betsill

Texas Parks and Wildlife Department's Inland and Coastal Fisheries Divisions have maintained a cooperative stocking program for marine red drum (Sciaenops ocellatus) in six freshwater power plant reservoirs since the early 1980s. We used experimental fish enclosures to analyze the effects of acclimation time (2.5 h vs. 5.0 h) and stocking season (summer vs. fall) on post stocking survival of red drum fingerlings in two of these power plant reservoirs. Calaveras and Tradinghouse Creek reservoirs were similar in size and depth, but Calaveras maintained total dissolved solids (TDS) and...

We evaluated the ability of oxytetracycline hydrochloride (OTC) and calcein (CAL) to double-mark otoliths in largemouth bass (Micropterus salmoides, LMB) fry and fingerlings. To observe longevity of marks, fish were sampled at six-month intervals for two years. Marks on fry otoliths disappeared rapidly regardless of chemical used; most marks were not visible after 180 days. Marks from CAL on fingerling otoliths were short-lived; 50% were not visible after 180 days. Marks from OTC on fingerling otoliths were visible on 100% of treated fish and were retained throughout the two years of study...

The relation between catch and effort is examined in the context of recreational fisheries. The concept of limited entry as a means of increasing angler catch rates is developed, empirical data demonstrating the catch-effort relationship are presented and ramifications of limited entry in fisheries management are discussed. Limited entry may have a place in the future of freshwater fisheries management.

I examined spring and fall electrofishing catch rates of largemouth bass (Micropterus salmoides) in 12 Texas reservoirs from 1986 to 1992 to assess the relative importance of spatial and temporal variation and to evaluate the relation between electrofishing catch rates and future angler catch. East Texas reservoirs were characterized by relatively greater temporal (i.e., annual) variation in electrofishing catch rates, whereas west Texas reservoirs tended to exhibit greater spatial variation. Reservoirs in east Texas shared a common temporal pattern in electrofishing catch rates....

Twelve adult fish, three each of northern and Florida largemouth bass (Micropterus salmoides and M. s. jloridanus) in each of 2 approximately 2-ha impoundments were implanted with ultrasonic transmitters and located over a period of 1 year to determine if distributional differences existed between the subspecies and to determine what factors might be responsible for any observed differences. Home range was beween 0.37 and 1.11 ha for all individuals. Average home range sizes were similar between subspecies and ponds. However, Florida bass generally made intensive use of small areas (i.e...