Date of Award
1-1-2006
Document Type
Thesis - ECU Access Only
Publisher
Edith Cowan University
Degree Name
Master of Science (Environmental Management)
School
School of Natural Sciences
Faculty
Faculty of Computing, Health and Science
First Supervisor
Jane Fromont
Second Supervisor
Jackie Alder
Third Supervisor
Paul Lavery
Abstract
Sponges were the dominant faunal benthic group, occupying 30 -50% of the limestone reef surface and displaying high diversity (>240 sponge species) on subtidal temperate reefs off Perth, Western Australia. Despite this high diversity there was little variation in composition among the six different sites sampled. However, there was within-site heterogeneity of sponge assemblages which has been ascribed to small-scale variation in light and sedimentation/abrasion rates. Differences in sponge assemblages were also detected between sampling times, species richness and sponge density were higher in winter compared to summer, whereas, sponge cover was higher in summer compared to winter. The results suggest that the growth and development of juveniles or annuals may have been adversely affected by the harsh conditions of winter. The higher temperatures in summer appeared to promote growth and reproduction of sponges.
Rapid assessment techniques have been proposed to look for patterns in biodiversity in conservation biology studies, when detailed routine surveys are not feasible. Two rapid assessment techniques were assessed, firstly examining the dominant sponge species; and secondly aggregating the sponge species to order level. The results of two rapid assessment techniques were promising if comparing sponge assemblages across habitats. If the aim was to assess sponge assemblages across sites, neither rapid assessment technique showed the same results compared to species level data. The general conclusion for subtidal temperate reef sponge assemblages within Marmion Lagoon is that there is substantial loss of information for spatial comparisons when aggregating species to order level or using only the dominant sponges. What was found was that the two levels failed to detect differences among sites which were found in the species level data analyses, but all three analyses gave the same results for habitat data.
In Western Australia only a few studies on sponges have been undertaken along the extensive coastline (12,500 km long). Previous sponge research in Western Australia occurred predominately as a result of taxonomic collections from expeditions undertaken in the 19th and early 201 h centuries. This study has described the 43 dominant sponge species that were found at six different sites on subtidal temperate reefs in Marmion Lagoon, Western Australia. Sponges were the dominant fauna found at most of the research sites off this coastal Perth location and included many species from a range of orders and families. Most of the species found occurred in sciaphilic (shade-loving) habitats. Only a few species occurred in full light conditions on the reef flats.
This study documented 243 sponge species from subtidal limestone reefs between 8-12 metres in depth within the Lagoon. These 243 species comprised 197 siliceous sponges (Class Demospongiae) and 46 calcareous sponges (Class Calcarea) and were identified to at least order. Eighteen were identified to order, 88 to family, 35 to genus and 56 to species level. Approximately 30% of the species recorded here are possibly new to science.
Recommended Citation
McQuillan, L. (2006). Species richness, density and cover of sponge assemblages on temperate reefs off Perth, Western Australia. Edith Cowan University. Retrieved from https://ro.ecu.edu.au/theses/359