|Author(s):||Katherine Cure, Jean-Paul A. HobbsTimothy J. Langlois, David A. Abdo, Scott Bennett, Euan S. Harvey|
|Title:||Distributional responses to marine heat waves: insights from length frequencies across the geographic range of the endemic reef fish Choerodon rubescens|
|Abstract:||Range shifts as a result of warming oceans call for evaluation of
populations at the geographic range level, particularly for highly
vulnerable species such as endemics and fisheries targets. We examined
the influence of latitudinal temperature gradients and temperature
anomalies during a 2011 marine heat wave on range-wide abundance, length
frequency and recruitment of Choerodon rubescens,
a reef associated fisheries target endemic to Western Australia.
Diver-operated stereo-video surveys were conducted at shallow reefs
(3–18 m) along 124 sites spanning the entire species’ distribution
(21°S–34°S), to obtain abundance, length frequency and habitat data.
Models were used to assess the influence of satellite-derived long-term
average temperature (2002–2010) and 2011 temperature anomalies, compared
to habitat, depth and distance to mainland, on the abundance of adult
and juvenile fish and overall population size structure. Long-term
temperature had the highest effect on adult C. rubescens
abundance, with highest values recorded towards the centre of the
temperature gradient investigated (22 °C). In contrast, juveniles were
mostly influenced by 2011 temperature anomalies, with highest abundance
recorded towards the cooler range edge, where anomalies were lowest.
Length-frequency distributions showed recent recruitment towards the
cooler range edge coupled with recruitment absence at the warmer edge.
Recruitment differences were traced to 2011–2013 when ocean temperatures
were up to 3.5 °C higher than average, via back-calculation of juvenile
ages. These findings support predictions of a poleward distributional
shift in response to ocean warming, and suggest that marine heatwaves
can facilitate range shifts by affecting recruitment across latitudinal
Related staffScott Bennett
Related departmentsOceanography and Global Change
Related research groupsGlobal Change Research