In 1969-70 there were 50 active commercial, heated fishing docks on Grand Lake, a 18,818 hectare reservoir in northeastern Oklahoma. During the winterspring of 1969-70, fishermen interviews were made to determine fishermen catch statistics. Docks were sampled Friday through Monday during the period 28 January through 30 April 1970. A total of 1365 interviewed fishermen caught 3963 fish in 4462 hours of fishing (0.89 fish/ man-hour). One carp (Cyprinus carpio) was captured, with the balance of 3962 fish in the sample represented by white crappie (Pomoxis annularis) of 239 mm mean total length and 194 g mean weight. Age composition of 234 fishermen caught fish was 94% age group III and IV, with age IV comprising 67.1% of the catch. The total population of fishermen using 41 of the 50 commercial docks was obtained from records kept by the dock operators. Using creel interviews at 50 docks, the winter-spring harvest of white crappie and man-days of fishing in the heated docks was estimated. Fishing pressure was determined by extrapolating total man-days from 41 to all 50 docks and harvest was obtained by multiplying sample catch rates by total man-hours. Extrapolated total man-days of fishing in heated docks in 93 days from 28 January through 30 April 1970 was 31,494 man-days. The average trip length for sample data was 4.9 hours/trip and the total man-hours was 153,562 hours. Applying 28 January through 28 February 1970 catch rate and fishing pressure, stratified by weekend-weekday, as an estimate of the same parameters for 1 November 1969 through 27 January 1970, the estimate of the wi nter-spring 1969-70 (I November through 30 April) fishing pressure was 60,016 man-days (3.19 man-days/ hal or 293,656 man-hours (15.60 man-hours/ hal. Estimated total harvest was 255,024 fish (13.534 fish/ hal or 48,962 kilograms (2.60 kg/ hal. Compared with kg/ ha values for crappie from nine southern reservoirs, the heated fishing dock harvest on Grand Lake was greater than three and would comprise at least 30% of four others. Furthermore, the Grand Lake heated dock harvest of crappie approximated 19% of the unweighted mean angler harvest of crappie (9.0 kg/ hal from 79 U.S. reservoirs. Rotenone samples in the summer of 1970 indicated a total standing crop of white crappie to be 24.43 kg; ha. The total harvest from heated dock fishing, those fish not usually harvested by fishermen, 18.3% of the biomass of catchable- sized crappie were harvested by winter anglers fishing indoors in heated docks.
