I. Nagelkerken et al., Importance of mangroves, seagrass beds and the shallow coral reef as a nursery for important coral reef fishes, using a visual census technique, EST COAST S, 51(1), 2000, pp. 31-44
The nursery function of various biotopes for coral reef fishes was investig
ated on Bonaire, Netherlands Antilles. Length and abundance of 16 commercia
lly important reef fish species were determined by means of visual censuses
during the day in six different biotopes: mangrove prop-roots (Rhizophora
mangle) and seagrass beds (Thalassia testudinum) in Lac Bay, and four depth
zones on the coral reef (0 to 3 m, 3 to 5 m, 10 to 15 m and 15 to 20 m). T
he mangroves, seagrass beds and shallow coral reef (0 to 3 m) appeared to b
e the main nursery biotopes for the juveniles of the selected species. Mutu
al comparison between biotopes showed that the seagrass beds were the most
important nursery biotope for juvenile Haemulon flavolineatum, H. sciurus,
Ocyurus chrysurus, Acanthurus chirurgus and Sparisoma viride, the mangroves
for juvenile Lutjanus apodus, L. griseus, Sphyraena baruacuda and Chaetodo
n capistratus, and the shallow coral reef for juvenile H. chrysargyreum, L.
mahogoni, A. bahianus and Abudefduf saxatilis. Juvenile Acanthurus coerule
us utilized all six biotopes, while juvenile H. carbonarium and Anisotremus
surinamensis were not observed in any of the six biotopes. Although fishes
showed a clear preference for a specific nursery biotope, most fish specie
s utilized multiple nursery biotopes simultaneously. The almost complete ab
sence of juveniles on the deeper reef zones indicates the high dependence o
f juveniles on the shallow water biotopes as a nursery. For most fish speci
es an (partial) ontogenetic shift was observed at a particular life stage f
rom their (shallow) nursery biotopes to the (deeper) coral reef. Cluster an
alyses showed that closely related species within the families Haemulidae,
Lutjanidae and Acanthuridae, and the different size classes within species
in most cases had a spatial separation in biotope utilization. (C) 2000 Aca
demic Press.