Small home range in southern Australia's largest resident reef fish, the western blue groper (Achoerodus gouldii): Implications for adequacy of no-take marine protected areas

No-take marine protected areas (MPAs) represent an effective biodiversity conservation tool for a range of species including resident reef fishes that are intrinsically vulnerable to overfishing and other localised impacts. The western blue groper (Achoerodus gouldii) is the largest permanent-resident reef teleost in southern Australian waters and has the second-oldest recorded age of any labrid at 70 years. Acoustic telemetry was used to investigate whether adult A. gouldii can be effectively protected within adequately sized no-take MPAs. Ten passive acoustic receivers tracked the movements of 15 A. gouldii individuals (69112-cm total length; 731-kg weight) at a site off north-western Kangaroo Island, South Australia. Most of the fish displayed high site fidelity (91100% residence time for 10 of the 11 fish with useful data) for a narrow strip of fringing coastal reef (∼1-km length by ∼40-m width) throughout a 12-month period. Mean home-range along-shore length and area were estimated at 1076±83m (s.e.), and 45188±3497m², respectively (n=11 fish with useful data). Comparison with other resident temperate-reef teleosts indicated no relationship between fish length and home-range area, and that A. gouldii has a relatively small home range. The high site fidelity and small home range of adult A. gouldii individuals makes localised populations amenable to a high level of protection within no-take MPAs.