Estimating the impact of sea kraits on the anguilliform fish community (Congridae, Muraenidae, Ophichthidae) of New Caledonia

Abstract

It has been previously shown that two guilds of predators, the sea kraits and their prey, the anguilliform fish (predator themselves), are far more abundant and diverse than previously suspected in coral reefs of the Indo-Pacific area. Based on diet, foraging range, feeding rate, and population size of two sea krait species, we estimated the annual uptake of anguilliform fish around Signal Island, New Caledonia. We found that more than 4000 snakes live on this 15 ha islet and that they can take up to 45 000 fish (>1.3 t) per year, essentially from 10 fish species previously considered as rare. One third of these fish are captured on the reef flat, the two other thirds within a 17 km radius surrounding Signal Island. We suggest that the foraging areas of the different snake populations belonging to numerous islets (and the surrounding reef flats) overlap greatly.