Underwater video surveys provide a more complete picture of littoral fish populations than seine samples in clear Florida springs

Abstract

Traditional fish-sampling methods may be problematic because of public use or safety concerns. In this study, we compared one common sampling method with video assessment of fish abundance and diversity in three springs that differed in water clarity and structure. At each of four or five sites per spring, we placed one GoPro camera on each bank for 12min and followed the filming with seine sampling. On the video, we counted the maximum number of individuals of each species observed within one frame (MaxN) and summed these counts to produce an estimate of fish abundance (SumMaxN). Then we compared abundance (SumMaxN), species richness and diversity between seine and video samples across all three springs. Video produced higher estimates of abundance (SumMaxN), species richness, and diversity than did seine sampling. However, this effect was largely confined to species richness and diversity differences between sample methods in the structurally complex spring; differences were subtle or non-existent in the low-structure spring and in the turbid spring. In all three springs, video captured relatively more centrarchids; these taxa were captured only rarely in seine samples. Therefore, video sampling performed as well or better than did seine sampling for fish-assemblage assessment in these clear springs.