Data

Ecological effects of introduced sessile marine invertebrates.

Australian Ocean Data Network
Barr, Lissa
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ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rfr_id=info%3Asid%2FANDS&rft_id=https://catalogue.aodn.org.au/geonetwork/srv/en/metadata.show?uuid=2122e200-bf2d-11dc-8728-00188b4c0af8&rft.title=Ecological effects of introduced sessile marine invertebrates.&rft.identifier=https://catalogue.aodn.org.au/geonetwork/srv/en/metadata.show?uuid=2122e200-bf2d-11dc-8728-00188b4c0af8&rft.publisher=Australian Ocean Data Network&rft.description=Manipulative field experiments were used to investigate the effects of the ascidians Botryllus schlosseri and Ascidiella aspersa and the bryozoan Bugula neritina on sessile invertebrate assemblages. Experiments were conducted on perspex plates suspended from Workshops Jetty, Williamstown, Victoria. All 3 introduced species affected the abundance of sessile marine invertebrates, but the effects were varied and not always negative or concentrated on native species. B. neritina increased the abundance of native species, A. aspersa increased the abundance of introduced species and B. schlosseri decreased the abundance of both native and introduced species. This research shows that effects of some introduced species are highly variable and do not conform to typical ideas that exist for introduced species.Experimental design Roughened black Perspex plates (110 x 110 x 6mm) were used to sample sessile invertebrate assemblages in all experiments. Plates were bolted onto PVC panels (800 x 800 x 5mm) at least 6mm apart. Panels with perspex plates attached were positioned in the water column so that the developing colonies faced the sediment surface. This was done to minimise algal growth and sedimentation on the assemblages.Laboratory processing Species identification and counts were made using a binocular dissecting microscope. Where possible the number of individuals on the entire plate were counted, excluding the 5mm perimeter of the plate and the area covered by the plaster block. Where the abundance of a species was > 100 individuals per plate, abundance was estimated from counts obtained on four random 20mm2 quadrats on each plate. These values were averaged and scaled up to numbers of individuals per plate. The abundance of colonial species was quantified as percentage cover. This was done by placing a 100 x 100 mm grid of 100 equal sized squares above the plate and counting the number of times the intersecting lines overlaid a portion of a colonial species.&rft.creator=Barr, Lissa &rft.date=2008&rft.coverage=northlimit=-37.861; southlimit=-37.861; westlimit=144.909; eastLimit=144.909&rft.coverage=northlimit=-37.861; southlimit=-37.861; westlimit=144.909; eastLimit=144.909&rft_rights=Contact author or point of contact for access to data.&rft_rights=This metadata may be downloaded for use in accordance with the Copyright Act 1968&rft_subject=biota&rft_subject=ENVIRONMENTAL IMPACTS&rft_subject=EARTH SCIENCE&rft_subject=HUMAN DIMENSIONS&rft_subject=COMMUNITY STRUCTURE&rft_subject=BIOSPHERE&rft_subject=ECOLOGICAL DYNAMICS&rft_subject=COMMUNITY DYNAMICS&rft_subject=SPECIES RECRUITMENT&rft_subject=Oceans | Marine Biology | Marine Invertebrates&rft_subject=Biosphere | Zoology | Invertebrates&rft_subject=BENTHIC HABITAT&rft_subject=AQUATIC ECOSYSTEMS&rft_subject=Workshops Jetty&rft_subject=Williamstown&rft_subject=Port Phillip Bay&rft_subject=Botryllus schlosseri&rft_subject=35 033006&rft_subject=Bugula neritina&rft_subject=20 331013&rft_subject=Bugula dentata&rft_subject=20 331002&rft.type=dataset&rft.language=English Access the data

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Manipulative field experiments were used to investigate the effects of the ascidians Botryllus schlosseri and Ascidiella aspersa and the bryozoan Bugula neritina on sessile invertebrate assemblages. Experiments were conducted on perspex plates suspended from Workshops Jetty, Williamstown, Victoria. All 3 introduced species affected the abundance of sessile marine invertebrates, but the effects were varied and not always negative or concentrated on native species. B. neritina increased the abundance of native species, A. aspersa increased the abundance of introduced species and B. schlosseri decreased the abundance of both native and introduced species. This research shows that effects of some introduced species are highly variable and do not conform to typical ideas that exist for introduced species.

Notes

To assess the ecological effects of 2 introduced ascidians and a bryozoan species on a sessile invertebrate assemblage in Port Phillip Bay, Victoria.
This thesis was carried out under the supervision of Dr Nathan Knott and Prof Mick Keough.

Lineage

Experimental design

Roughened black Perspex plates (110 x 110 x 6mm) were used to sample sessile invertebrate assemblages in all experiments. Plates were bolted onto PVC panels (800 x 800 x 5mm) at least 6mm apart. Panels with perspex plates attached were positioned in the water column so that the developing colonies faced the sediment surface. This was done to minimise algal growth and sedimentation on the assemblages.
Laboratory processing

Species identification and counts were made using a binocular dissecting microscope. Where possible the number of individuals on the entire plate were counted, excluding the 5mm perimeter of the plate and the area covered by the plaster block. Where the abundance of a species was > 100 individuals per plate, abundance was estimated from counts obtained on four random 20mm2 quadrats on each plate. These values were averaged and scaled up to numbers of individuals per plate. The abundance of colonial species was quantified as percentage cover. This was done by placing a 100 x 100 mm grid of 100 equal sized squares above the plate and counting the number of times the intersecting lines overlaid a portion of a colonial species.

Issued: 30 04 2004

Data time period: 2003-11 to 2004-3

This dataset is part of a larger collection

144.909,-37.861

144.909,-37.861

text: northlimit=-37.861; southlimit=-37.861; westlimit=144.909; eastLimit=144.909