FACTORS AFFECTING DISTRIBUTION AND ABUNDANCE OF SMALL DEMERSAL FISHESIN THE GULF-OF-CARPENTARIA, AUSTRALIA

The distribution and abundance of small demersal fishes at depths of 7 to 63 m in the Gulf of Carpentaria were surveyed at 103 stations an 1 990 and 60 stations in 1991 with the aid of a Church dredge. A total o f 234 species from 70 families was recorded The most abundant fish,gro ups were cryptic or benthic species such as pleuronectiforms, scorpaen ids, apogonids, platycephalids, monacanthids and gobiids. Several spec ies, such as Elates ransonnetti, Pseudorhombus elevatus and Suggrundus macracanthus, are widely distributed; others had a narrower distribut ion. Apogon poecilopterus, Apogon fasciatus, Amoglossus waitei and Ura noscopus cognatus were most abundant in the northern Gulf of Carpentar ia and Cynoglossus macrophthalmus, Dactyloptena papilio and Paramonaca nthus japonicus in the eastern gulf. The dredge is more efficient at c atching smaller fish: the smallest individuals of 113 species were cau ght by the dredge and a further 32 small species were caught only by t he dredge. The effects of depth, substratum type and turbidity on the abundance of 17 common species at different stations are described. Ne ither temperature nor salinity showed significant correlations with ca tches of the common species There were significant correlations betwee n;the presence of structured benthos and both the number of fish speci es and the number of fish individuals. The relationship between benthi c structure and fish is discussed in relation to the possible effects of trawling and it is postulated that changes to structure resulting f rom trawling may affect fish community composition.