Recherche Archipelago

Summary

Research Objectives

To identify, classify and map the distribution of, different benthic habitats in the Recherche Archipelago and link their distributions to bottom type and exposure to swells and currents.
To provide detailed ecological information to ensure the responsible management of aquaculture fisheries in the region.
To increase community awareness of fish habitats through community involvement in the development of baseline studies and ongoing monitoring programs.

Outcomes achieved to date

The design of a hierarchical classification scheme of benthic habitats in the Recherche Archipelago. Modelling of the effectiveness of that classification scheme
An extensive habitat map of the Western Recherche Archipelago at both broad and functional habitat classifications and less detailed habitat maps of duke of Orleans Bay and Cape Arid to Middle Island.
An oceanographic model of the influence of ocean swells on the Western Recherche Archipelago. This model includes an assessment of swell driven shear at the benthos.
A broad scale fisheries-independent non-destructive survey of the demersal fish of the Recherche from Esperance Bay to Cape Arid. The survey was designed to capture habitat differences (habitats defined from the mapping exercise) in fish assemblages
A broad scale (within the Western Archipelago) survey of the infauna found in a range of soft bottom habitats (as defined from the mapping exercise) including coarse sands, rhodoliths and sparsely vegetated sands.
Fine scale diversity surveys of reef communities on islands in the archipelago from Figure of Eight to Middle Island. These surveys included assessments of macroalgae, sessile invertebrates and reef fish with depth and exposure to ocean swells. Thus they integrate information from both habitat mapping and physical oceanographic modelling.
Finally, the project is a joint Esperance community (through the Recherche Advisory Group - RAG), research scientist and resource management project. The commitment of RAG has allowed the researchers to efficiently transfer scientific information to the general public of Esperance and the South Coast of Western Australia and keep the research focussed on management outcomes.

Non technical overview

Extensive broad scale surveys were made in the relatively clear waters of the Recherche Archipelago. Where there was adequate light penetration sidescan sonar was used allowing almost photographic quality imagery of seafloor texture to be obtained from swaths of up to 400 m wide. Drop and towed video systems were used to obtain more detailed information about the physical and biological nature of the seabed in areas identified from the acoustic mapping. A total of 1054 km2 of habitats were mapped within the Recherche Archipelago. A total of 813 km2 was mapped in the Esperance region, 142 km2 in the Cape Arid region and 99 km2 in the Duke of Orleans region.

Reports and technical papers

Characterising the fish habitats of the Recherche Archipelago (88 KB PDF)

Fisheries Research and Development Corporation Report. Project No. 2001/060. ISBN: 1 74052 123 4.
Authors: Dr G. Kendrick, Dr Euan Harvey, Dr Justin McDonald, Professor Chari Pattiaratchi, Mike Cappo, Dr Jane Fromont, Professor Mark Shortis, Simon Grove, Andy Bickers, Katrina Baxter, Dr Nisse Goldberg, Mat Kletczkowski, and James Butler.

Characterising the Fish Habitats of the Recherche Archipelago (21 MB PDF), Fisheries Research and Development Corporation Project No. 2001/060
Case studies designed to identify, classify and map the distribution of, different benthic habitats in the Recherche Archipelago and to link their distributions to bottom type and exposure to swells and currents. It provides detailed ecological information to ensure the responsible management of aquaculture and fisheries in the region; and was aimed at increasing community awareness of fish habitats through community involvement in the development of baseline studies and ongoing monitoring programs.
Authors: Gary A. Kendrick, Euan Harvey, Justin McDonald, Chari Pattiaratchi, Mike, Cappo, Jane Fromont, Mark Shortis, Simon Grove, Andy Bickers, Katrina Baxter, Nisse Goldberg, Mat Kletczkowski, James Butler.

Coastal Geomorphology Subproject (CG): Report on the Relationships between Marine Geology and the Benthic Habitats of the Recherché Archipelago inner shelf, Western Australia (2 MB PDF).
CRC Milestone Report CG4.04B
Authors: David Ryan, Brendan Brooke, Lindsay Collins, Andy Bickers, Katrina Baxter, and Justy Siwabessy.
This paper examines the relationships between bottom sediments, geomorphology, wave energy and the distribution of benthic habitats in Esperance Bay, an inner-shelf area typical of the Recherché Archipelago.

Coastal CRC Coastal Water Habitat Mapping Project Coastal Geomorphology Subproject (CG) Report on the field survey in Esperance Bay, Recherché Archipelago, Western Australia, May 2-16, 2005
(2 MB PDF).
Milestone Report CG5.02 Brendan Brooke, David Ryan, David Holdway and Justy Siwabessy.
A major aim of this study was to build on the first Recherche survey by obtaining complete multibeam coverage for the Woody Island Group by "filling in" between the existing small areas of multibeam coverage around the islands.

Identification of seafloor habitats in coastal shelf waters using a multibeam echosounder
(805 KB PDF)
Proceedings of ACOUSTICS 2004 3-5 November 2004, Gold Coast, Australia.
Parnum, I.M.*, Siwabessy, P.J.W. and Gavrilov A.N., Centre for Marine Science and Technology, Curtin University of Technology, and Coastal Zone CRC.

Cost Effective Marine Habitat Mapping from Small Vessels using GIS, Sidescan Sonar and Video
(2 MB PDF).
Andrew Bickers. Ph.D. Student / Engineer. Marine Science Group, School of Plant Biology,
University of Western Australia.

Multibeam echo sounder backscatter analysis. Analysis of swath backscatter data collected in the region of Recherche Archipelago
(2 MB PDF)
A.N. Gavrilov, P.J.W. Siwabessy and A. Bickers. CMST report 2005-8. Cooperative Research Centre for Coastal Zone Estuary and Waterway Management.

more information on a comprehensive list of references on the use, comparison, precision and accuracy of using stereo-video systems to estimate fish lengths.

Spatial sampling: Capturing fish distribution and habitat usage data at multiple scales (1 MB PDF). This segment describes a method for improving sampling of fish distributions and habitat usage. This segment describes a plan for secondary sampling, based on:
1. Analysis of data from a preliminary field sampling dataset
2. The capture of sites across a range of depths and habitats
3. The concentration of sites to test for spatial dependence in fish distributions.