Assessment of the Abundance of Flying Fishes by Visual Observations

Abstract

AbstractVisual census of flying fishes leaping out of the water when frightened by a passing ship may be used for numerical estimation of their abundance. The method is, however, in need of substantial improvement because of uncertainty of species identification in situ, difficulties in counting specimens in large schools and in estimating proportion of specimens leaping, inadequate knowledge of patchiness, and inaccuracy in conversion of numbers into biomass. Further development of the method should involve instrumental observations including photography, filming, or video-magnetic recording.