This experiment examined the temporal changes in species composition and diversity of a developing epifaunal community on artificial substrata at Portsea. The substrata used were the bare uncaged panels and cage control panels used in the experiment described in the record 'Effects of predation by fishes on the establishment of the epifaunal community at Portsea, Victoria' (File Identifier: fd9aa0f0-e4c2-11dc-9b6b-00188b4c0af8). There were 4 replicate panels that were immersed for 2, 4 or 7 months on rigs under the Portsea Pier and 6 runs of the experiment from October 1975 to November 1977. At the conclusion of each run of the experiment the panels were fixed in 4% formalin-seawater solution. In the laboratory, the number of individuals and percent cover of colonial species on each panel were recorded. In general, the 3 most abundant colonists (barnacle Elminius modestus, tubicolous amphipods and the colonial ascidian Diplosoma rayneri) in the first 2 months decreased as the experiments proceeded. In the following months the surfaces were invariably dominated by arborescent bryozoans, particularly Bugula dentata and Tricellaria porteli and encrusting bryozoans, particularly Celleporaria fusca. Once arborescent bryozoans exceeded a height of 15mm they frequently escaped overgrowth by most encrusting species. In all runs of the experiment there was an initial and usually rapid increase in diversity followed by a decrease.

Exclusions were attached to artificial substrata to investigate the relative effects of predation on the development of epifaunal communities at Portsea. Exclusions were black plastic mesh cages enclosing panels that were attached to rigs under the Portsea Pier. Bare control panels and cage controls where included in the experimental design. Cage controls had the bottom and half of the roof on the cage removed. There were 2 replicate panels of each treatment that were immersed for 2, 4 or 7 months and there were 6 runs of the experiment from October 1975 to November 1977. At the conclusion of each run of the experiment the panels were fixed in 4% formalin-seawater solution. In the laboratory, the number of individuals and percent cover of colonial species on each panel were recorded. Surveys identified that grazing fish were the most abundant predator of the epifaunal community at Portsea during the experiment. Predation significantly affected the pattern of establishment of the epifaunal community. There were fewer ascidian recruits and more diverse communities on bare control panels because fish predation prevented monopolisation of space by dominant ascidian competitors. On caged panels were there was no fish grazing, the survival of colonial ascidians was greater and the panels were dominated by arborescent bryozoans and ascidians.

The resource provides information on the rates of growth, competitive ability and life spans of species in the epifaunal community at Portsea. Estimates of rates of growth for all species were collected from panels immersed on 16/11/1977 except for the common barnacle (Elminius modestus) and ascidian (Didemnum augusti) which were collected from panels immersed on 24/10/1975. Length and average width of colonies or individuals and maximum height of arborescent bryozoans were made at regular intervals during the time of immersion. Colonial ascidians were the most rapid occupiers of space. In general, colonial ascidians and sponges attained a larger size and occupied space more rapidly than encrusting bryozoans. Competitive interactions between species were examined using the same panels as described in the record 'Patterns of development in the epifaunal community at Portsea, Victoria' (File identifier: a88f2d70-ebf6-11dc-a93a-00188b4c0af8). These panels had been immersed for 2 to 42 months and fixed in formalin-sea water solution. Approximately 5500 interactions were recorded between 52 species. An interaction was defined as the overgrowth or smothering of an organism by another organism of the same or different species. For each interaction the species involved were identified, the sizes of the interacting organisms were measured and the percentage of overgrowth, if any, was estimated visually in increments of 5% overgrowth of the colony or individual. There was no single competitively dominant species in the marine epifaunal community at Portsea. The competitive ability of a species depended on the rate of growth of the species and the maximum size they could attain. The relative size of interacting colonies was often important in determining the outcome of an interaction with larger colony generally winning. The maximum life span for each species was estimated from observations of communities on panels and on pier pilings over the 4 year period of the study (October 1975 to November 1979). The life spans of the major groups of epifauna on panesl at Portsea followed the order sponges (>24 months) > ascidians (~ 12 - 20 months) > bryozoans (~ 8 - 20 months) > barnacles, polychaetes, tubicolous amphipods and hydroids (4 - 12 months).

Artificial substrata were used to investigate the patterns of establishment and change in the structure of a subtidal, marine epifaunal community at Portsea, Victoria from October 1975 to November 1979. Sessile invertebrate species and mobile species that significantly affected the distribution and abundance of the sessile species were the focus of the study. Experiments examining variability in recruitment and community development, species competitive ability, and the effects of predation on the epifaunal community at Portsea are outlined in the related records.

This study investigated the ecology of caridean shrimp in eelgrass habitats in Western Port Bay, Victoria from July 1977 to January 1980. The study sites were located on the Churchill Tidal Flats on the northern side of Phillip Island, which are dominated by the eelgrass species, Heterozostera tasmanica and the cardiean shrimp species, Macrobrachium intermedium, Pontophilus candidus, Hippolyte caradina and Chlorotocella leptorhyncus. Benthic trawls were used to sample the shrimp populations at an offshore (Site A) and inshore (Site B) eelgrass site. Another site on a mudflat (Site C) was sampled to determine the movement patterns of shrimps between the mudflats and adjacent subtidal eelgrass areas. Sampling was undertaken every 1 to 2 months at night time during high tide. Plankton tows were used to monitor the presence of larval stages of shrimp in the water column. Details of each experiment and results are described in the related records.

Predation on newly settled individuals has been shown to shape sessile invertebrate communities of the northeast coast of North America. This study tests if this response can also be observed at other geographic locations that support different assemblage of sessile invertebrates. The effects of predation in early post-settlement assemblages were tested at two locations in Victoria; Workshops Pier, Williamstown and Queenscliff Pier, Queenscliff during the summer of 2005-2006. At each site, early post-settlement assemblages of sessile invertebrates were established and subsequently exposed to a series of predation exclusion treatments of varying durations. This dataset gives the abundances of sessile invertebrates on plates at Williamstown Pier after the initial 4 day settlement period, and after subsequent exposure to 3, 15 and 35 days exposure to three predation exclusion treatments. The predation treatments were i) uncaged, no predator exclusion, ii) full 2 mm mesh cage, total predator exclusion and iii) full 10 mm mesh cage, exclusion of large predators only. In addition two cage control treatments were established to identify if the cages themselves caused a change in the sessile invertebrate assemblages. Cage controls were partial cages constructed from both 2 mm and 10 mm mesh. The results indicated that, although predators were common, predation did not exert a strong influence on sessile invertebrate communities at Williamstown.

Predation on newly settled individuals has been shown to shape marine sessile invertebrate communities of the northeast coast of North America. This study tests if this response can also be observed at other geographic locations that support different assemblage of marine sessile invertebrates. The effects of predation in early post-settlement assemblages were tested at two locations in Victoria; Workshops Jetty, Williamstown and Queenscliff Pier, Queenscliff during the summer of 2005-2006. At each site, early post-settlement assemblages of sessile invertebrates were established and subsequently exposed to a series of predation exclusion treatments of varying durations. This dataset gives the abundances of sessile invertebrates at Queenscliff Pier after an initial 4 day settlement period, and 20 and 40 days after these initial assemblages were exposed to three predation exclusion treatments: i) uncaged, no predator exclusion; ii) full 2 mm mesh cage, total predator exclusion; iii) full 10 mm mesh cage, exclusion of large predators only. In addition two cage control treatments were established to identify if the cages themselves caused a change in the sessile invertebrate assemblages. Cage controls were partial cages constructed from both 2 mm and 10 mm mesh. The results indicated that didemnid ascidians may have been preyed upon by a small predator, but this predator was not identified. However, predation did not exert a strong influence on other taxa or on the overall structure of sessile invertebrate communities at Queenscliff.

This study investigated the influence of predation on the distribution of shrimp in Western Port Bay from July 1977 to January 1980. Predation by birds was determined by analysing the diets and feeding rates of the most abundant wading birds in the area, the Royal Spoonbill (Platalea regia), the White-faced Heron (Ardea novaehollandiae), and the Sacred Ibis (Threskiornis aethiopica). Predation by fish was determined by examining the gut contents of fish caught in the beam trawls. The shrimps found in the gut contents were identified and, where possible, sexed and carapace length measured. This study found that the major consumers of shrimps were the scorpaenid, Gymnapistes marmoratus (Australian Cobbler) and the short-headed worm-eel, Muraenichthys breviceps. The Royal Spoonbill feed almost solely on M.intermdieum, whereas the other 2 species of waders feed mostly on infauna. The larger-sized individuals, which tend to be females, are subject so higher predation pressure than other groups within species.

This study investigated the influence of predation on the distribution of shrimp in Western Port Bay from July 1977 to January 1980. Predation by birds was determined by analysing the diets and feeding rates of the most abundant wading birds in the area, the Royal Spoonbill (Platalea regia), the White-faced Heron (Ardea novaehollandiae), and the Sacred Ibis (Threskiornis aethiopica). Predation by fish was determined by examining the gut contents of fish caught in the beam trawls. The shrimps found in the gut contents were identified and, where possible, sexed and carapace length measured. This study found that the major consumers of shrimps were the scorpaenid, Gymnapistes marmoratus (Australian Cobbler) and the short-headed worm-eel, Muraenichthys breviceps. The Royal Spoonbill feed almost solely on M.intermdieum, whereas the other 2 species of waders feed mostly on infauna. The larger-sized individuals, which tend to be females, are subject so higher predation pressure than other groups within species.