Dine-in or delivery: are locally-produced or imported food sources more important to coastal reef fish biomass over large scales?

Miss Amy Rose Coghlan¹, Dr. Julia Blanchard¹, Dr. Asta Audzijonyte¹, Dr. Rick Stuart-Smith¹

¹Institute For Marine And Antarctic Science, Hobart, Australia

Abstract:

The productivity, species composition and growth rates of coastal reef fish assemblages are changing in response to habitat degradation and climate change, yet to better predict the ecological consequences of these changes we must clarify the role of benthic/pelagic food sources. Whilst it is often assumed that coastal reef systems rely primarily upon benthic food sources, recent studies in coastal upwelling regions have demonstrated that coastal reef fish assemblages may  depend almost entirely on pelagic productivity. It is currently unclear to what extent this applies to different coastal ecosystems. If coastal reef fish assemblages depend largely upon planktonic food sources, incorporating plankton transport and distribution into coastal ecosystem models is a key priority. As planktonic food sources are usually ‘imported’ rather than locally produced, coastal fish assemblages may be strongly affected by processes impacting plankton production elsewhere. This study aims to explore the role of benthic and pelagic food sources along tropical-temperate gradient of Australian coastal reefs, in one of the world’s fastest warming areas. We will use bulk and/or compound specific stable isotope analyses, along with gut content analysis, to compare the relative contribution of benthic and pelagic carbon sources to reef fish biomass using ~1000 fish from broad functional groups (herbivores, planktivores, omnivores, corallivores and predators) at 8 locations along the East Australian coast (Tasmania-Far North Queensland). The findings will then be incorporated into size spectrum benthic pelagic ecosystem models to explore a range of climate change and species redistribution scenarios and their consequences for the ecosystem function.

Biography:

Worked [holidayed] with sea-things in many places:  University of Western Australia, Otago University New Zealand, Komodo Indonesia, University of British Colombia Canada, Charles Darwin Foundation Glapagos Ecuador, and is now at the Institute for Marine and Antarctic Science Tasmania. Enjoys SCUBA & free-diving, climbing, hiking, skiing, sailing, Ultimate Frisbee, and sometimes photos these things (500px.com/amroco). An overall fan of marine invertebrates; appreciates fish common names, but on the fence about Halichoeres bivittatus.