Data

Ecological effects of the introduced fanworm, Sabella spallanzanii (Gmelin, 1791), on hard substratum epifaunal assemblages

Australian Ocean Data Network
Holloway, M.G.
Viewed: [[ro.stat.viewed]] Cited: [[ro.stat.cited]] Accessed: [[ro.stat.accessed]]
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:443/geonetwork/srv/api/records/df6a9ff0-1fb9-11dc-8df0-00188b4c0af8&rft.title=Ecological effects of the introduced fanworm, Sabella spallanzanii (Gmelin, 1791), on hard substratum epifaunal assemblages&rft.identifier=https://catalogue.aodn.org.au:443/geonetwork/srv/api/records/df6a9ff0-1fb9-11dc-8df0-00188b4c0af8&rft.description=Sabella spallanzanii is an introduced sabellid ploychaete that is thought to be native to the Mediterranean and east Atlantic coast. Since its first identification in Port Phillip Bay in 1992 it has spread rapidly and occurs in most parts of the bay. This thesis examines the ecological impact of Sabella spallanzanii aggregations on hard substrate epifaunal assemblages in south eastern Australia. Specifically the effects of Sabella on: a) recruitment of sessile invertebrates; b) development of epifaunal assemblages; c) distribution of larvae and other planktonic organisms and d) growth and survival of sessile animals are examined. These effects are evaluated in relation to spatial and temporal changes in Sabella canopies resulting from changes in populations and patterns of fan deployment. Studies were carried out between 1995 and 1998 at four sites within Port Phillip Bay, Victoria (Geelong Marina, Breakwater Pier, Victoria Dock and St Kilda Marina) and at Outer Harbour, within the Gulf of St Vincent, South Australia. The effects of Sabella on recruitment of sessile taxa were complex, but a number of generalisations could be made. Recruitment of some barnacles, bryozoan, spirorbid and ascidian taxa to large experimentally cleared (pilings) areas was higher than on uncleared areas. On the scale of individual 20 by 20 cm settlement plates, where the effects of physical structure was controlled using fanworm mimics, most of the effects were caused by the presence of physical structure on the plate. Positive and negative responses of some taxa were observed but responses were not consistent across experiments. Recruitment onto tubes increased the abundance of several taxa on plates with fanworms, but not all taxa recruited onto tubes. Results were not consistent within taxonomic groups or between sites. Longer term experiments revealed fewer changes to the structure of the understorey assemblage. The apparent disappearance of canopy effects with time could be caused by processes associated with assemblage development such as overgrowth and senescence of early recruits. Alternatively it could simply be caused by differences in the composition of assemblages between experiments. Multivariate analyses showed that spatial variation in recruitment on the scale of 10's of metres was important in determining the composition of the assemblage in both early and later stages. The planktonic abundances of larval solitary ascidian, spionid polychaetes and pooled larval taxa adjacent to the substratum were significantly reduced by the presence of a fanworm canopy, suggesting that larval flux to these areas may be lower. Little difference in larval recruitment between cleared and uncleared areas suggests that settlement rates may be enhanced or post-settlement mortality rates might be lower beneath canopies. Growth of the arborescent bryozoan Bugula stolonifera and an encrusting bryozoan Watersipora subtorquata were affected by the presence of a canopy, but these effects were not consistent between experiments. This variability suggests that canopies may act in different ways at different times. The overall impact of Sabella spallanzanii on other species at the scales examined in this thesis can not be explained by its modification of the habitat. The use of tubes as settlement sites, and the predominance of small scale responses to physical structure support this idea. Any impact of Sabella spallanzanii must also be evaluated in the light of observations that the canopy was not constant though time, due to population crashes that occurred at a number of times and places.Maintenance and Update Frequency: notPlanned&rft.creator=Holloway, M.G. &rft.date=2007&rft.coverage=westlimit=138.48898; southlimit=-38.14386; eastlimit=144.9656; northlimit=-34.7743&rft.coverage=westlimit=138.48898; southlimit=-38.14386; eastlimit=144.9656; northlimit=-34.7743&rft_rights=Please contact the author for access to the data.&rft_rights=This data remains the Intellectual Property of the original owner of the data, it may be downloaded for use in accordance with the Copyright Act 1968.&rft_subject=biota&rft_subject=Oceans | Marine Biology | Marine Invertebrates&rft_subject=BENTHIC HABITAT&rft_subject=EARTH SCIENCE&rft_subject=BIOSPHERE&rft_subject=AQUATIC ECOSYSTEMS&rft_subject=COASTAL HABITAT&rft_subject=COMMUNITY STRUCTURE&rft_subject=ECOLOGICAL DYNAMICS&rft_subject=COMMUNITY DYNAMICS&rft_subject=SPECIES RECRUITMENT&rft_subject=Biosphere | Ecological Dynamics | Competition&rft_subject=Biosphere | Ecological Dynamics | Life History&rft_subject=Sabella spallanzanii&rft_subject=sabellid polychaete&rft_subject=epifauna&rft_subject=22 083031&rft_subject=Breakwater Pier, Williamstown VIC&rft_subject=Victoria Dock, Melbourne VIC&rft_subject=Geelong Marina, VIC&rft_subject=St Kilda Marina, VIC&rft_subject=Outer Harbour, SA&rft_subject=marine introductions&rft_subject=exotic species&rft_subject=habitat modification&rft_subject=biological effects&rft_subject=larval supply&rft_subject=life histories&rft_subject=canopy effects&rft_subject=recruitment&rft.type=dataset&rft.language=English Access the data
Cite Saved to MyRDA Save to MyRDA

Licence & Rights:

view details

Please contact the author for access to the data.

This data remains the Intellectual Property of the original owner of the data, it may be downloaded for use in accordance with the Copyright Act 1968.

Access:

Other

Brief description

Sabella spallanzanii is an introduced sabellid ploychaete that is thought to be native to the Mediterranean and east Atlantic coast. Since its first identification in Port Phillip Bay in 1992 it has spread rapidly and occurs in most parts of the bay. This thesis examines the ecological impact of Sabella spallanzanii aggregations on hard substrate epifaunal assemblages in south eastern Australia. Specifically the effects of Sabella on: a) recruitment of sessile invertebrates; b) development of epifaunal assemblages; c) distribution of larvae and other planktonic organisms and d) growth and survival of sessile animals are examined. These effects are evaluated in relation to spatial and temporal changes in Sabella canopies resulting from changes in populations and patterns of fan deployment. Studies were carried out between 1995 and 1998 at four sites within Port Phillip Bay, Victoria (Geelong Marina, Breakwater Pier, Victoria Dock and St Kilda Marina) and at Outer Harbour, within the Gulf of St Vincent, South Australia. The effects of Sabella on recruitment of sessile taxa were complex, but a number of generalisations could be made. Recruitment of some barnacles, bryozoan, spirorbid and ascidian taxa to large experimentally cleared (pilings) areas was higher than on uncleared areas. On the scale of individual 20 by 20 cm settlement plates, where the effects of physical structure was controlled using fanworm mimics, most of the effects were caused by the presence of physical structure on the plate. Positive and negative responses of some taxa were observed but responses were not consistent across experiments. Recruitment onto tubes increased the abundance of several taxa on plates with fanworms, but not all taxa recruited onto tubes. Results were not consistent within taxonomic groups or between sites. Longer term experiments revealed fewer changes to the structure of the understorey assemblage. The apparent disappearance of canopy effects with time could be caused by processes associated with assemblage development such as overgrowth and senescence of early recruits. Alternatively it could simply be caused by differences in the composition of assemblages between experiments. Multivariate analyses showed that spatial variation in recruitment on the scale of 10's of metres was important in determining the composition of the assemblage in both early and later stages. The planktonic abundances of larval solitary ascidian, spionid polychaetes and pooled larval taxa adjacent to the substratum were significantly reduced by the presence of a fanworm canopy, suggesting that larval flux to these areas may be lower. Little difference in larval recruitment between cleared and uncleared areas suggests that settlement rates may be enhanced or post-settlement mortality rates might be lower beneath canopies. Growth of the arborescent bryozoan Bugula stolonifera and an encrusting bryozoan Watersipora subtorquata were affected by the presence of a canopy, but these effects were not consistent between experiments. This variability suggests that canopies may act in different ways at different times. The overall impact of Sabella spallanzanii on other species at the scales examined in this thesis can not be explained by its modification of the habitat. The use of tubes as settlement sites, and the predominance of small scale responses to physical structure support this idea. Any impact of Sabella spallanzanii must also be evaluated in the light of observations that the canopy was not constant though time, due to population crashes that occurred at a number of times and places.

Lineage

Maintenance and Update Frequency: notPlanned

Notes

Credit
This thesis was carried out under the supervision of Prof Mick Keough.
Credit
Dr Jon Havenhand at Flinders University, SA provided material support and advice during field trips to Adelaide.
Purpose
This research was carried out to provide a better understanding of the ecological impact of Sabella spallanzanii aggregations on hard substrate epifaunal assemblages.

Created: 21 06 2007

Data time period: 04 1995 to 03 1999

This dataset is part of a larger collection

Click to explore relationships graph
Help

Related Organisations

Related People

144.9656,-34.7743 144.9656,-38.14386 138.48898,-38.14386 138.48898,-34.7743 144.9656,-34.7743

141.72729,-36.45908

text: westlimit=138.48898; southlimit=-38.14386; eastlimit=144.9656; northlimit=-34.7743

Subjects
22 083031 | AQUATIC ECOSYSTEMS | Benthic Habitat | BIOSPHERE | Biosphere | Ecological Dynamics | Competition | Biosphere | Ecological Dynamics | Life History | Breakwater Pier, Williamstown VIC | Coastal Habitat | COMMUNITY DYNAMICS | Community Structure | EARTH SCIENCE | ECOLOGICAL DYNAMICS | Geelong Marina, VIC | Oceans | Marine Biology | Marine Invertebrates | Outer Harbour, SA | Species Recruitment | Sabella spallanzanii | St Kilda Marina, VIC | Victoria Dock, Melbourne VIC | biological effects | biota | canopy effects | epifauna | exotic species | habitat modification | larval supply | life histories | marine introductions | recruitment | sabellid polychaete |

User Contributed Tags    

Login to tag this record with meaningful keywords to make it easier to discover

Identifiers
  • global : df6a9ff0-1fb9-11dc-8df0-00188b4c0af8
Similar data you may be interested in: