Oral Presentation Australian Society for Fish Biology Conference 2017

Suitable surrogacy for decadal-scale conservation planning in a warming subtropical region with persistent patterns and shifting species (#135)

Hamish A Malcolm 1 , Renata Ferrari 2 , Anna Scott 3 , Alan R Jordan 4 , Adriana Vergés 5
  1. Fisheries Research, NSW Department of Primary Industries, Coffs Harbour, NSW, Australia
  2. School of Biological Sciences, University of Sydney, Sydney, NSW, Australia
  3. National Marine Science Centre, Southern Cross University, Coffs Harbour, NSW, Australia
  4. Fisheries Research, NSW Department of Primary Industries, Port Stephens, NSW, Australia
  5. School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW, Australia

Faced with climate change and associated species range shifts, effective conservation strategies that suitably represent biodiversity need to account for both present and future species distributions and be robust to future warming. We consider this principle in relation to the Solitary Islands Marine Park (SIMP), a warming region in subtropical eastern Australia. Over the last decade, the habitat-forming kelp Ecklonia radiata has markedly declined in this region, corresponding with changes in herbivory and a tropicalisation of fish communities. Further evidence of tropicalisation includes a southwards extension of anemonefishes and host sea anemones since the mid-1990s. In light of these changes, can conservation planning for biodiversity representation be undertaken for decadal time-scales, the scale at which zoning plans in multiple-use Marine Protected Areas often operate? In support that it can, strong cross-shelf patterns in reef fish assemblages (inshore, mid, offshore) have been maintained over the decadal scale in the SIMP. These patterns have been used to help refine a Habitat Classification System (HCS) for application in conservation planning (e.g. using Marxan) through surrogate biodiversity representation. Loss of kelp habitat on mid reefs reduced heterogeneity of the habitat mosaic present in the region, impacting diversity and thereby affecting representation. However, persistence in broad assemblage patterns indicate that a well-designed HCS is a robust and informative tool for representing biodiversity in conservation planning in the face of climate change. Likewise, predictive models of species/functional group distributions and abundances have considerable utility for longer-term planning, although caution is required in their interpretation. Predictive models support the importance of distance from shore and depth as categories in the HCS. Marxan analyses using predictive models versus HCS categories indicate advantages and disadvantages in both approaches. If possible, a combination of both approaches is preferred, especially when also incorporating local knowledge of sites with exceptionally high biodiversity.

  1. Vergés A, Doropoulos C, Malcolm HA, Skye M, Garcia-Piza M, Marzinelli EM, Campbell AH, Ballesteros E, Hoey AS, Vila-Concejo A, Bozec Y-M, Steinberg PD (2016). Long-term empirical evidence of ocean warming leading to tropicalization of fish communities, increased herbivory, and loss of kelp. Proceedings of the National Academy of Science Early Edition, www.pnas.org/cgi/doi/10.1073/pnas.1610725113
  2. Malcolm HA and Scott A (2016). Range extensions in anemonefishes and host sea anemones in eastern Australia: potential constraints to tropicalisation. Marine and Freshwater Research. Early view http://dx.doi.org/10.1071/MF15420
  3. Malcolm HA, Jordan A, Schultz AL, Smith SDA, Ingleton T, Foulsham E, Linklater M, Davies PL, Ferrari R, Hill N, Lucieer V (2016). Integrating seafloor habitat mapping and fish assemblage patterns improves spatial management planning in a marine park. Journal of Coastal Research, Special Issue 75: 1292-1296
  4. Malcolm HA, Foulsham E, Pressey RL, Jordan A, Ingleton T, Davies PL, Johnstone N, Hesse S, Smith SDA (2012). Selecting zones in a marine park: early systematic planning improves cost-efficiency; combining habitat and biotic data improves effectiveness. Ocean and Coastal Management 59: 1-12.
  5. Malcolm HA, Jordan A, Smith SDA (2010). Biogeographical and cross-shelf patterns of reef fish assemblages in a transition zone: implications for conservation planning. Marine Biodiversity 40: 181-193
  6. Malcolm HA, Smith SDA, Jordan A (2010). Using patterns of reef fish assemblages to refine a Habitat Classification System for marine parks in NSW, Australia. Aquatic Conservation: Marine and Freshwater Ecosystems 20: 83-92