COMPARISON OF FISH ASSEMBLAGES ASSOCIATED WITH SEAGRASS AND ADJACENT UNVEGETATED HABITATS OF PORT-PHILLIP BAY AND CORNER INLET, VICTORIA, AUSTRALIA, WITH EMPHASIS ON COMMERCIAL SPECIES
Gp. Jenkins et al., COMPARISON OF FISH ASSEMBLAGES ASSOCIATED WITH SEAGRASS AND ADJACENT UNVEGETATED HABITATS OF PORT-PHILLIP BAY AND CORNER INLET, VICTORIA, AUSTRALIA, WITH EMPHASIS ON COMMERCIAL SPECIES, Estuarine, coastal and shelf science, 44(5), 1997, pp. 569-588
Species richness, abundance and biomass of fishes from seagrass and un
vegetated habitats were analysed for sites in the Swan Bay region of P
ort Phillip Bay, and Corner Inlet, Victoria, Australia. Fish assemblag
es from intertidal Zostera muelleri sites showed greater similarity wi
th a number of shallower unvegetated sites than to subtidal Heterozost
era tasmanica. Similarly, subtidal, unvegetated sites in Swan Bay were
more similar to subtidal Heterozostera sites than to other, generally
shallower, unvegetated sites. Species richness was significantly high
er in seagrass beds and showed an increase over the warmer months of t
he year. Differences in abundance and biomass of fishes between vegeta
ted and unvegetated habitats depended on the location of sampling. In
general, abundance and biomass of fish in the deeper subtidal seagrass
were significantly higher than in unvegetated habitats of the same de
pth. In contrast, abundance and biomass were not significantly differe
nt between seagrass and unvegetated habitats of the intertidal and sha
llow subtidal zones when significant abundances of the long-finned gob
y, Favonigobius lateralis, occurred on unvegetated habitats. As a cons
equence, species richness would be expected to decrease with any seagr
ass loss; however, decreases in abundance and biomass of fishes would
be greatest with loss of deeper subtidal Heterozostera habitats. Altho
ugh juveniles of a number of commercially important species were assoc
iated with subtidal Heterozostera habitats, juveniles of other species
of commercial significance were found on shallow, unvegetated habitat
s. Newly settled juveniles of the King George whiting, Sillaginodes pu
nctata, were associated with unvegetated patches amongst subtidal seag
rass in Swan Bay, in contrast with a direct association with seagrass
reported from other areas. (C) 1997 Academic Press Limited.