A survey of fish species occurring in the marine waters of northern New South Wales was conducted at five sites between October 1988 and February 1996. The principal study site was at Julian Rocks, located approximately five km north of Cape Byron, Australia's most easterly mainland point. The other study sites included: Windarra Bank, located 16 km east of Mooball; Wilsons Reef, located 2 km south-west of Julian Rocks; Lennox Head Moat located at the southern extreme of Seven Mile Beach, Lennox Head and Belongil Creek, located two km west of Byron Bay township.
A total of 530 fish species in 293 genera and 115 families was recorded from the study area. The total was composed of 394 (74.3%) tropical species, 103 (19.4%) temperate species and 31 (5.8%) subtropical species. The remaining two (0.4%) species have circum-global or circum-Australian distributions.
Eighty-four (15.8%) of the species recorded are restricted to the South-Western or South Pacific Oceans and 96 (18.1%) are endemic to Australia. The endemics comprised: 19 (3.6%) tropical species; 48 (9.1%) temperate species; and 29 (5.5%) subtropical species. Two (0.4%) of the species recorded occur in both tropical and temperate seas and two species are primarily freshwater fish, one of which, Gambusia holbrooki (mosquito fish) is introduced.
The 394 tropical species dominated the fish assemblage at the study sites. However, when the relative abundances of tropical, subtropical and temperate fish species are compared, the percentage of “common” tropical species (6.3%) was significantly less than the “common” subtropical (38.7%) or “common” temperate (19.4%) counterparts.
The most speciose families were: Labridae (74 species); Pomacentridae (43); Chaetodontidae (26); Serranidae (24); Acanthuridae (19); Monacanthidae (16); Carangidae (16); Scorpaenidae (14); Pomacanthidae (13); Scombridae (13) and Tetraodontidae (13).
A total of 114 (21.5%) tropical species in 31 families had not previously been recorded from New South Wales. Similarly, 12 (2.2%) temperate species in 10 families had not previously been recorded as far north as the study area.