Brief description
Disturbance events are thought to provide an opportunity for the colonisation and establishment of invasive species. Contamination of coastal waters with copper from sewage outfall and antifouling paints may create a disturbance that favours the establishment of introduced sessile invertebrates. This study examines if the frequency of experimentally applied doses of copper sulfate increases the abundance of introduced sessile invertebrate species within developing (2-weeks old) and established (9-months old) assemblages. Responses to regular and irregularly applied doses of copper were also tested in developing assemblages. This dataset gives the effects of copper pulse frequency on the number of native and introduced taxa within developing (2-weeks old) sessile invertebrate assemblages. Studies were carried out over 16 weeks between October 2004 and January 2005 at two sites in Port Phillip Bay, Victoria; Workshops Jetty, Williamstown and Point Henry Pier. Workshops Jetty is reported to have higher abundances of sessile invertebrates and is more polluted than Point Henry Pier, providing a comparison between sites with different community assemblages and environment conditions. At Workshops Jetty, four treatments were tested: an undosed control, or copper pulses applied every 4, 3 or 2 weeks. At Point Henry, the same treatments were applied, except for the copper pulse application every 3 weeks. Overall, this study found no evidence to support the hypothesis that disturbance facilitates invasions by introduced species. Disturbance had no effect on the proportion of introduced species and there were no clear differences in the responses on introduced and native species. Whether a species benefited from a disturbance appeared to depend more on its life history characteristics, rather than its point of origin.Lineage
Maintenance and Update Frequency: notPlanned
Statement: Roughened black Perspex plates (110 x 110 x 6mm) were used to establish sessile invertebrate colonies. 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.
Individual plaster blocks were made using 3g of analytical grade CuSO4 dissolved in 13ml of deionised water. This solution was chilled and mixed with 15g of CSR dental plaster and poured into 4mm diameter moulds. A stainless steel bolt was inserted head down into the centre of each mould to provide a means of attaching the blocks to the plates. The solution was allowed to set at 30°C for 7 days. Control blocks were made in the same way but without the addition of CuSO4.
Species identification and counts were made using a binocular dissecting microscope. Where possible the number of individuals on the entire plate was counted, excluding the 5 mm 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 20 mm2 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.
Statement: 1. Source:
a. Dataset: This dataset gives the effects of copper pulse frequency on the number of native and introduced taxa within developing marine sessile invertebrate assemblages. Studies were carried out over 16 weeks between October 2004 and January 2005 at two sites in Port Phillip Bay, Victoria; Workshops Jetty, Williamstown and Point Henry Pier. Workshops Jetty is reported to have higher abundances of sessile invertebrates and is more polluted than Point Henry Pier, providing a comparison between sites with different community assemblages and environmental conditions. Sessile invertebrate assemblages were established on Perspex plates attached to a backing panel (see collectionHardware) and placed in the water column at a minimum depth of 2-3m. To minimise algal growth and sedimentation on the assemblages the panels were positioned so that the developing colonies faced the sediment
After two weeks sessile invertebrates assemblages had started to develop on the plates at each site and these were subject to copper pulses of varying frequencies. Plaster blocks made from dental plaster mixed with copper sulfate were used to create a localized region of higher copper concentration lasting ~ 2 days. Blocks were also made without copper and used as un-dosed controls (see collection Hardware).
At Workshops Jetty, four treatments were tested: an un-dosed control, or copper pulses applied every 4, 3 or 2 weeks. At Point Henry, the same treatments were applied, except for the copper pulse application every 3 weeks. At both sites, each treatment was applied to 6 replicate plates. Two of the six replicate plates were attached to each of three backing panels and returned to the water column. After 16 weeks plates were retrieved and the abundance of native and introduced taxa identified and counted using a binocular dissecting microscope (see collectionHardware).
The data columns in the dataset are: Site (Workshop Pier, Point Henry), Panel Number (1, 2, 3); Treatment (0, undosed plaster block applied; 4, copper block applied every 4 weeks; 3, copper block applied every 3 weeks, 2, copper block applied every 2 weeks NB: Whenever a particular treatment recieved a copper block, all other plates recieved an undosed control block); Status (Introduced, Native, Unknown), The remaining data columns give the abundance or percent cover of identified taxa.
For more details on the methods and experimental design see Loughman, R.J. (2005). Do disturbances facilitate invasion of marine invertebrate assemblages by pests?, Honours Thesis, Department of Zoology, University of Melbourne.
b. Scale: counts are expressed as either number of individuals per plate or as percentage cover
c. Media Types: Not Relevant
d. Date:
e. Dates of various parts of the process:
Colonies establishment over 2 weeks in October 2004
Copper pulse treatments applied over 16 weeks, between October 2004 & January 2005.
Identification and enumeration of taxa on plates at the end of the experiment in January 2005.
2. Processing Steps:
a. Intermediate processing steps (after data capture): see collectionHardware
b. Methods used to generate final product: Not Relevant
Notes
CreditThis thesis was supervised by Dr Nathan Knott and Professor Mick Keough.
Credit
Parks Victoria gave permission to work at Workshops Jetty, Williamstown.
Parks Victoria gave permission to work at Workshops Jetty, Williamstown.
Purpose
To determine whether the frequency of exposure to copper pulses influences the abundance of introduced sessile invertebrates at two sites in Port Phillip Bay, Victoria
To determine whether the frequency of exposure to copper pulses influences the abundance of introduced sessile invertebrates at two sites in Port Phillip Bay, Victoria
Created: 27 02 2007
Data time period: 2004-10-01 to 2004-12-30
text: westlimit=144.43492; southlimit=-38.12881; eastlimit=144.90819; northlimit=-37.86078
text: uplimit=1; downlimit=1
Subjects
10 000000 |
11 500000 |
20 000000 |
22 000000 |
27 500000 |
35 000000 |
Arborescent bryozoan |
Ascidiacea |
BIOSPHERE |
Barnacles |
Bryozoa |
COMMUNITY DYNAMICS |
Community Structure |
Contaminants |
Cnidaria |
Colonial ascidian |
EARTH SCIENCE |
ECOLOGICAL DYNAMICS |
Encrusting bryozoan |
Oceans | Marine Biology | Marine Invertebrates |
Point Henry Pier |
Polychaeta |
Porifera |
Port Phillip Bay, Victoria |
Species Recruitment |
Solitary ascidian |
TERRESTRIAL HYDROSPHERE |
Trace Metals |
WATER QUALITY/WATER CHEMISTRY |
Workshops Jetty, Williamstown |
biota |
copper |
experimental_treatment |
panel_id |
site |
status |
taxonomic_group_count |
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Other Information
Identifiers
- global : 31c373e0-1262-11dc-a108-00188b4c0af8
