Alan Jordan, NSW Department of Environment, Climate Change and Water

There are six Marine Parks in New South Wales that cover 345,000 hectares, or around 34 percent of NSW coastal waters. Their primary aims are to conserve marine biodiversity, maintain valuable ecosystems and support sustainable uses of the marine environment. The zoning plan outlines what activities can be undertaken in different areas of the Marine Park, primarily through the application of four types of zones: sanctuary, habitat protection, general use and special purpose zones.

Under Australian State and Commonwealth planning policies, a key objective of marine park planning is to achieve comprehensive, adequate and representative (CAR) protection of ecosystems and habitats, and in doing so protect the full range of biological diversity. In order to maximise the likelihood that zoning arrangements fulfil CAR objectives, a seabed mapping program has been underway for several years detailing the distribution, extent and structure of seabed habitats on the inner and mid-continental shelf of New South Wales.

Multibeam sonar mapping conducted by the CERF Marine Biodiversity Hub within Jervis Bay Marine Park (JBMP) and Lord Howe Island Marine Park (LHIMP) has provided a considerable amount of seabed coverage within these areas. In JBMP these data have been combined with extensive swath acoustic data collected using the NSW Department of Environment, Climate Change and Water’s interferometric side scan sonar bathymetry system allowing the development of high resolution maps of seabed bathymetry, backscatter and habitats. The Marine Hub mapping identified significant additional areas of complex inner-shelf reef within JBMP reflecting the bedrock geomorphology of the area. In LHIMP, the Marine Hub bathymetry data have been combined with our maps of shallow reefs digitised from aerial photos to provide new insights into the structure and extent of seabed habitats on the Lord Howe Island shelf. In particular, large areas of limestone hardground on the outer shelf were identified as a ‘relic’ coral reef and mapped at high resolution, significantly improving the knowledge of this unique temperate reef system.

Both of these marine parks are undergoing a 5 year review of their zoning plans, and these datasets have significantly contributed to the information on seabed habitats, enhancing our capacity to assess the CAR planning criteria. The zoning plans in NSW marine parks were developed using a benthic habitat classification system as a surrogate for biodiversity, and habitat classification is likely to remain a key marine park planning tool in NSW. However, the effectiveness of habitats as a planning and management tool will depend, to some extent, on how well they represent patterns of biodiversity. We have been combining maps of seabed habitats from a number of sources with site-specific information on species composition to increase the range of biodiversity surrogates being employed. This in turn has improved our ability to inform park planning and the assessment of the effectiveness of marine park locations and specific zoning arrangements for representing biological diversity in NSW.

The NSW habitat maps have also led to specific projects that aim to document and monitor the community composition of specific habitats. In particular, the sonar bathymetry coverage has significantly improved the capacity to examine the relationship between fish community structure and sessile benthic assemblages, and spatial parameters such as reef complexity, patchiness and rugosity. Given the need to predict biodiversity from the most useful surrogates for effective MPA planning, the Marine Biodiversity Hub program is an important contributor to the information required by the NSW Marine Parks Authority.

Contact: Dr Alan Jordan, Head, Marine Conservation Science Unit, Waters and Coastal Science, NSW Department of Environment, Climate Change and Water alan.jordan@environment.nsw.gov.au

Photo:
Relic reef on Lord Howe Island shelf that often contains a diverse benthic community including solitary hard corals, soft corals, sponges, ascidians, encrusting bryozoans, hydroids, starfish, sea urchins, molluscs, crustaceans and a dense cover of algae including foliose and nodular coralline species. Galapagos sharks are also very common on the shelf habitats.

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