Cascading effects of global climate change on near shore benthic communities in the Antarctic
Entry ID: ASAC_2300

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Summary
Abstract: Metadata record for data from ASAC Project 2300
See the link below for public details on this project.

---- Public Summary from Project----

Antarctic reefs, like their tropical counterparts, harbour a high diversity of animal life. For the first time we will determine how global warming will affect food availability to the animals which comprise the structural components of the reefs. Ultimately, we wish to predict the cascading effect through the community as one component changes.

With the confirmation that sponges in Antarctic waters graze on ultraplankton there is now a global overview that sponges are the primary benthic organism that is responsible for linking the pelagic microbial food web to the benthos. Like other shallow water demosponges, sponges in Antarcticia are omnivorous sponges that graze nonselectively, consuming both heterotrophic and phototrophic organisms. Retention efficiencies of ultraplankton are similar to other sponges measured using similar techniques from shallow water to the deep sea, the tropics to boreal waters.

The large amounts of water processed by these benthic suspension feeders and their diet places these sponges squarely within the functional group of organisms that link the pelagic microbial food web to the benthos. The number of macroinvertebrates that have been shown to side- step the microbial loop and directly utilize the base of the microbial food web as a primary food source is ever growing and currently includes demosponges, ascidians, soft corals, and bivalves. Dense macroinvertebrate communities dominated by demosponges and corals in shallow water have been shown to remove as much as 90% of the ultraplankton from the water that passes over them. The daily fluxes of ultraplankton to these communities ranges from 9 to 1970 mg C day-1 m-2. We conservatively estimate that this single species of sponge, which comprises only a portion of the benthos, mediates a flux of 444 mg mg C day-1 m-2 from the water column, which places it in the range of shallow-water temperate and boreal systems.

Furthermore, we found that physical disturbance results in changes in community structure. The subtidal rocky coasts near Casey are similar to many of the exposed rocky coasts of the world that support extensive stands of macroalgae that form a strong positive association with understorey encrusting coralline algae. Loss of canopies of algae on temperate coasts often triggers large and predictable changes to the assemblage of understorey taxa. We observed large negative effects of removing canopies of H. grandifolius on encrusting corallines growing beneath, with such effects consistent with predictions of previous research on tropical and temperate coasts. However, elevating concentrations of nutrients did not greatly reduce the magnitude of the negative effects of canopy removal. Nevertheless, our results suggest that disturbance (removal) to canopies of H. grandifolius has large consequences for those organisms associated with this widely distributed (circumpolar) species of canopy-forming algae.

See the full copy of the final report (available for download from the URL given below) for more information.

Also included in the download file, are five Excel spreadsheets. The spreadsheets contain the data collected from the transects, quadrats, etc (see the final report for more information). Where possible the spreadsheets have been converted to csv files.

The fields in this dataset are:

Location
depth
Species
Transect
Quadrat
Irradiance
PAR

Related URL
Link: GET DATA
Description: Download point for the data - final report and data


Link: VIEW PROJECT HOME PAGE
Description: Public information for ASAC project 2300


Link: VIEW RELATED INFORMATION
Description: Citation reference for this metadata record and dataset


Geographic Coverage
 N: -65.0 S: -68.0  E: 110.0  W: 62.0

Temporal Coverage
Start Date: 2003-09-30
Stop Date: 2005-03-31


Location Keywords
CONTINENT > ANTARCTICA
GEOGRAPHIC REGION > POLAR


Science Keywords
BIOLOGICAL CLASSIFICATION >ANIMALS/INVERTEBRATES    [Definition]
BIOLOGICAL CLASSIFICATION >ANIMALS/INVERTEBRATES >SPONGES    [Definition]
BIOLOGICAL CLASSIFICATION >PLANTS >MICROALGAE    [Definition]
BIOLOGICAL CLASSIFICATION >PLANTS >MACROALGAE (SEAWEEDS)    [Definition]
BIOSPHERE >AQUATIC ECOSYSTEMS >PLANKTON >ZOOPLANKTON    [Definition]
BIOSPHERE >AQUATIC ECOSYSTEMS >PLANKTON >PHYTOPLANKTON    [Definition]
BIOSPHERE >AQUATIC ECOSYSTEMS >PLANKTON    [Definition]
BIOSPHERE >AQUATIC ECOSYSTEMS >BENTHIC HABITAT    [Definition]
BIOSPHERE >ECOLOGICAL DYNAMICS >SPECIES/POPULATION INTERACTIONS >SPECIES PREDATION    [Definition]
BIOSPHERE >ECOLOGICAL DYNAMICS >SPECIES/POPULATION INTERACTIONS >GRAZING DYNAMICS/PLANT HERBIVORY    [Definition]


ISO Topic Category
BIOTA
OCEANS


Platform
FIELD SURVEYS    [Information]
FIELD INVESTIGATION    [Information]


Instrument
Thermistors    [Information]
FLOW CYTOMETRY    [Information]


Quality
Values provided in temporal and spatial coverage are approximate only.

This record has been updated by staff at the Australian Antarctic Data Centre (rather than the listed investigator), and therefore it's accuracy and quality cannot be guaranteed.

See the final report at the URL below for full and accurate information.


Access Constraints
These data and a copy of the final report are available for download from the URL given below.


Use Constraints
This data set conforms to the PICCCBY Attribution License
(http://creativecommons.org/licenses/by/3.0/).

Please follow instructions listed in the citation reference provided at the
URL below when using these data.


Keywords
ANTARCTICA
BENTHIC COMMUNITIES
CLIMATE CHANGE
sponges
coralline
ultraplankton
quadrats
transects


Data Set Progress
COMPLETE


Data Center
Australian Antarctic Data Centre, Australia    [Information]
Data Center URL: http://data.aad.gov.au

Data Center Personnel
Name: DATA OFFICER AADC
Phone: +61 3 6232 3244
Fax: +61 3 6232 3351
Email: metadata at aad.gov.au
Contact Address:
Australian Antarctic Division
203 Channel Highway
City: Kingston
Province or State: Tasmania
Postal Code: 7050
Country: Australia



Distribution
Distribution_Media: HTTP
Distribution_Size: 24 kb
Distribution_Format: word, csv, excel
Fees: free


Personnel
ADELE PILE
Role: INVESTIGATOR
Role: TECHNICAL CONTACT
Role: DIF AUTHOR
Phone: +61 2 9351 2440
Fax: +61 2 9351 2558
Email: apile at bio.usyd.edu.au
Contact Address:
School Of Biological Sciences
University of Sydney
RM 202A HAYDON-LAURENCE BLDG A08
City: Sydney
Province or State: New South Wales
Postal Code: 2006
Country: Australia


Publications/References
Irving, A. D., S. D. Connell, E. L. Johnston, A. J. Pile, B. M. Gillanders. (2005), The response of encrusting coralline algae to canopy loss: an independent test of predictions on an Antarctic coast., Marine Biology, 144, 361-368

Pile, AJ, EL Johnston, SD Connell and BM Gillanders. (December 2005), Benthic-pelagic coupling of the microbial food web by Antarctic sponges, Targeted for Marine Ecology Progress Series

Johnston EL, SD Connell, AD Irving, AJ Pile and BM Gillanders (December 2005), Characterising shallow rocky-reef assemblages from the Windmill Islands coast, East Antarctica, Targeted for Polar Biology

Connell, SD, EL Johnston, AD Irving, TE Wernberg, BM Gillanders, BD Russell, AJ Pile (May 2006), How do the understorey assemblages at the Windmill Islands of Antarctica compare to those in Australia?, Targeted for Polar Biology

Creation and Review Dates
DIF Creation Date: 2003-05-26
Last DIF Revision Date: 2014-08-29

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