Centre for Marine Futures

Data analysis is showing an incredibly diverse marine environment, probably owing to the influence of the Leeuwin and Capes currents that pass the region.

Past work and future sampling 

Marine communities in the semi-sheltered waters of Geographe and Flinders Bays are quite different from those on the exposed western coast from Cape Naturaliste to Cape Leeuwin. Future sampling will build on the existing dataset and provide information that will enable detection of changes in marine communities in the Capes region and in proposed sanctuary zones of the Capes Marine Reserve.

Data were collected on the abundance and size (or biomass) of fishes, algae and large mobile invertebrates from 21 sites in the Capes region (Cape Naturaliste - Geographe Bay to Cape Leeuwin - Flinders Bay). 

Forty-two species of fishes were recorded from underwater video census (UVC) with the highest number of species at the Flinders region and the highest diversity at the Naturaliste region and the Geographe Bay Ridge. There were no significant differences in fish assemblages between different regions (Naturaliste, Freycinet, Hamelin or Flinders) or between proposed sanctuary and general-use zones within each region. 

Baited remote underwater video sampling (BRUV), conducted at the Naturaliste and Injidup regions, recorded 69 species of fishes, many in common with fishes recorded in UVC.  There were no significant differences between regions or sites sampled with BRUV.

The number of algal species recorded in this survey (221 species from 50 families) is comparable with other studies from the temperate Australian coast. Twenty-one species of mobile macroinvertebrates were recorded at the Capes region, dominated by seastars, urchins, gastropod shells and nudibranchs.

The highest diversity was recorded at the Flinders region.