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Distribution models of temperate habitat-forming species on the continental shelf In eastern Australia: setting the baseline to monitor and predict future changes

Citation

Marzloff, MP and Barrett, N and Holbrook, N and Oliver, ECJ and James, L and Johnson, CR, Distribution models of temperate habitat-forming species on the continental shelf In eastern Australia: setting the baseline to monitor and predict future changes, Proceedings of the 21st International Congress on Modelling and Simulation (MODSIM2015), 29 November-04 December 2015, Broadbeach, QLD ISBN 9780987214355 (2015) [Conference Extract]

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Abstract

Habitat-formers (e.g. kelp beds, corals, sessile invertebrate assemblages) are key to the structure and functioning of reef ecosystems worldwide. In southeast Australia, a region identified as a global hotspot for climate-driven ocean warming, the structure and distribution of deep (> 30 m) benthic sessile communities are poorly known given these habitats are hard to quantitatively survey. Using high-resolution imagery of the seafloor from a recent national-scale AUV-based survey program, we establish a critical baseline about the latitudinal gradient in benthic community composition from 27S to 43S on the eastern seaboard of Australia.

Over >1,800 AUV images taken across the 7 different survey regions along the eastern seaboard of Australia, we estimated percentage cover of 51 pre-selected invertebrate morphospecies, including two ascidians, four bryozoans, seven cnidarians and 38 sponges. These morphospecies were chosen for their strong features (i.e. size, shape, colour), which facilitated their identification and detectability on the images. Three levels of details (i.e. group, shape, colour) were reported for each record, so as to test the sensitivity of our results to alternative invertebrate classification schemes of increasing resolution.

Large-scale latitudinal variability between three major community types (sub-tropical, warm temperate and cool temperate) mostly correlates with primary productivity and temperature climatology, while local scale variability relates well with depth.

Using environmental variables that capture past climatology both in terms of means and extremes (frequency and magnitude), we develop alternative distribution models for several habitat-forming species. Our models characterise the thermal tolerance of individual morphospecies in terms of suitable and/or critical boundary conditions. We compare model performance, discriminate between different types of latitudinal distribution (e.g. truncated or continuous), identify indicator morphospecies more likely to respond to climate-driven changes in ocean conditions, and discuss these results in the context of ongoing and future ocean changes. Our study provides an important benchmark to detect and predict future climate-driven changes in southeastern Australia, and our methodology has general applicability for monitoring of deep reef environments.

Item Details

Item Type:Conference Extract
Keywords:Autonomous Underwater Vehicle, effects of climate change on deep reef communities, East Australian Current, benthic invertebrates, range shifts, habitat-formers, habitat mapping, Eastern Australia, temperate reef, deep reef
Research Division:Environmental Sciences
Research Group:Ecological Applications
Research Field:Ecosystem Function
Objective Division:Environment
Objective Group:Ecosystem Assessment and Management
Objective Field:Ecosystem Assessment and Management of Marine Environments
Author:Marzloff, MP (Dr Martin Marzloff)
Author:Barrett, N (Dr Neville Barrett)
Author:Holbrook, N (Associate Professor Neil Holbrook)
Author:Oliver, ECJ (Dr Eric Oliver)
Author:James, L (Ms Lainey James)
Author:Johnson, CR (Professor Craig Johnson)
ID Code:107665
Year Published:2015
Deposited By:IMAS Research and Education Centre
Deposited On:2016-03-21
Last Modified:2016-03-23
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