Paper Reviewed
Cure, K., Hobbs, J-P. A. and Harvey, E.S. 2015. High recruitment associated with increased sea temperatures towards the southern range edge of a Western Australian endemic reef fish Choerodon rubescens (family Labridae). Environ Biol Fish 98: 1059-1067.

Choerodon rubescens is a subtropical wrasse endemic to Western Australia that is an important commercial and recreational fisheries target throughout its normal distribution, primarily along the central portion of its range. More recently, however, catch records indicate that the popular reef fish has become more common in the southern part of its range, suggestive of the possible poleward expansion or shifting of its preferred habitat.

To explore this possibility, Cure et al. (2015) assessed the size structure and habitat associations of juvenile C. rubescens during the summer and autumn of 2013 (January-May) by means of an underwater visual census conducted across available shallow water habitats towards the southern range edge of their historic distribution (32°S, 115°E). And what did they discover by so doing?

The three Australian researchers report that "high abundances of juveniles (up to 14 fish/40 m²) were found in areas where they were previously absent or in low abundance." And based on the size structure of the populations they encountered, they say that "recruitment was estimated to occur during summer 2011-12 and 2012-13," which "coincides with water temperatures 1 to 2°C higher than long-term averages in the region, making conditions more favorable for recruits to survive in greater numbers." And in wrapping up their report, they say it "mirrors the well-established patterns observed on the east coast of Australia," citing the studies of Booth et al. (2007), Figueira et al. (2009), Figueira and Booth (2010) and, last of all, Last et al. (2011).

References
Booth, D.J., Figueira, W.F., Gregson, M.A., Brown, L. and Beretta, G. 2007. Occurrence of tropical fishes in temperate southeastern Australia: role of the East Australian Current. Estuarine and Coastal Shelf Science 72: 102-114.

Figueira, W.F. and Booth, D.J. 2010. Increasing ocean temperatures allow tropical fishes to survive overwinter in temperate waters. Global Change Biology 16: 506-516.

Figueira, W., Biro, P., Booth, D. and Valenzuela, V. 2009. Performance of tropical fish recruiting to temperate habitat: role of ambient temperature and implications of climate change. Marine Ecology Progress Series 384: 231-239.

Last, P.R., White, W.T., Gledhill, D.C., Hobday, A.J., Brown, R., Edgar, G.J. and Pecl, G.2011. Long-term shifts in abundance and distribution of a temperate fish fauna: a responses to climate change and fishing practices. Global Ecology and Biogeography 20: 58-72.