Ba. Henry et Gp. Jenkins, THE IMPACT OF PREDATION BY THE GIRDLED GOBY, NESOGOBIUS SP 1, ON ABUNDANCES OF MEIOFAUNA AND SMALL MACROFAUNA, Journal of experimental marine biology and ecology, 191(2), 1995, pp. 223-238
It is now widely accepted that benthic meiofauna and small macrofauna
are an important food source for numerous species of benthic fish. The
effect of fish predation on prey populations, however, has been contr
oversial. The girdled goby, Nesogobius sp. I, is a benthic marine fish
that is abundant on the mudflats of Swan Bay, Victoria. A short-term
(48 h) held caging experiment, where gobies were excluded or included
at low and high densities, was used to determine the effect of predati
on. Predation by gobies was found to significantly affect the abundanc
e of their main prey item, juvenile amphipods. However, this effect on
ly occurred at fish densities higher than those normally found in the
environment. There were no significant effects on other prey items, an
d no significant effect on amphipods at ''natural'' fish densities. Ca
lculations based on the feeding rates of gobies and the abundances of
prey at the study site were consistent with the experimental results.
Therefore, we conclude that, in the short term at least, predation by
Nesogobius sp. 1 is unlikely to influence the abundances of its prey.
Calculations based on feeding rates suggest that a long-term effect of
predation by gobies on amphipods may be possible depending on the tur
nover rate of prey populations.