Use of night‐lights to attract food organisms into tropical marine fish cages

摘要

Abstract.A 91‐day cage trial was conducted with juvenile seabass, Lates calcarifer (Bloch), and grouper, Epinephelus tauvina (Forskal), to ascertain the capacity of kerosene pressure lamps and fluorescent electric lamps as night‐lights above the cages to attract pelagic food organisms into the cage and consequently sustain the survival and growth of the cultured fish. The experiment was conducted using 1×1×1·5m floating cages with three different net mesh sizes (1, 13, and 19mm) and four fish stocking densities (seabass—10, 20,30 and 40/m3; grouper —10/m3). A positive growth response and survival was observed with seabass and to a lesser extent with grouper with increasing net mesh size and decreasing fish stocking density. At the lowest tested density of 10 fish/m3seabass survival increased from 5·0 to 95·0 and total cage fish biomass increased from −95·1 to +56·9 with an increase in net mesh size from 1 to 19mm over the 91‐day culture trial, respectively. The results are discussed in relation to the current commercial marine finfish cage farming practices emp