This study examined the species composition and size structure of fish and
macroinvertebrates captured by two dual-mesh beach seines of different leng
ths. Both nets captured small fish, large fish and juveniles. The longer ne
t appeared to be the best choice as a sampling tool, but support for this c
hoice was not strong. The assemblages caught by the two nets differed, but
these differences did not mask overall spatial and temporal patterns in ass
emblage composition. The longer seine caught more species, but estimates of
total densities for all individuals and densities of three common, commerc
ially important fish species did not differ consistently between the two ne
ts. Comparisons and generalizations based on studies that use different typ
es of seines should be interpreted cautiously because design features may i
nfluence results in inconsistent and unpredictable ways.