A COMPARISON OF 4 ENCLOSURE TRAPS AND METHODS USED TO SAMPLE FISHES IN AQUATIC MACROPHYTES

Sampling efficiency Of four enclosure fish traps -- a square, mesh-sided 1.0-m2 throw trap; a light weight, square, metal-sided 1.0-m2 throw trap; a heavier, square, metal-sided 1.0-m2 throw trap; and a circular 2.27-m2 drop trap -- were compared in two vegetation types in Lake Okeechobee, Florida. Estimates of total fish/m2 for all species pooled, fish/m2 for each of the five most abundant species, and species/m2 were similar among traps. Clearing method (dip nets or bar seine) did not affect estimates of total fish/m2 for the heavier, metal-sided throw trap or the mesh-sided throw trap. Trap clearing and sample picking methods used with the light weight throw trap and 2.27-m2 drop trap required greater field effort. Samples from the 2.27-m2 drop trap required 18 times more laboratory processing time than the average sample taken with a throw trap. Although all traps yielded similar estimates of fish density and species density, a 1.0-m2 throw trap was the most efficient method with regard to field and laboratory effort.