AN ASSESSMENT OF BURBOT (LOTA-LOTA) WEIGHT LENGTH DATA FROM NORTH-AMERICAN POPULATIONS

Declining burbot (Lota lota) abundance across some portions of North A merica has prompted a search for additional evaluation tools, includin g a measure of condition. Weight-length data were compiled for 10 293 burbot from 79 North American populations. These data were used to dev elop a 75th percentile standard weight (W-s) equation using the regres sion-line-percentile technique. The proposed equation is log(10) W-s = -4.868 + 2.898 log(10) TL, where W-s is the standard weight in grams, and TL is the maximum total length in millimetres. The equation is va lid for burbot greater than or equal to 20 cm and will allow calculati on of relative weights (W-r) for this species. Based on the length of the longest burbot in our data set (104.3 cm), we propose minimum stan dardized length categories of 20, 38, 53, 67, and 82 cm for stock, qua lity, preferred, memorable, and trophy length, respectively. The stand ard length categories will allow determination of mean W-r by length g roup, as well as calculation of stock density indices. Differences in W-r values were present between lentic and lotic burbot populations, s uggesting variation in body shape and a need for establishment of diff erent W-r objective ranges.