Limnological and nearshore diatom communities of Macquarie Island: proxies of subantarctic climate change?Entry ID: ASAC_2663
Abstract: Metadata record for data from ASAC Project 2663
See the link below for public details on this project.
Macquarie Island offers scientists a unique laboratory for investigating subantarctic climate change. We will establish the biodiversity of microalgal flora (specifically diatoms) within the lakes and lagoons of Macquarie Island and ultimately use the flora of today to investigate ... changes in fossil microalgal communities of Macquarie Island lake and lagoon ecosystems to better understand past, present and future climate change in the Australian Subantarctic.
Taken from the abstract of the referenced paper:
This study is the first established survey of diatom-environment relationships on sub-Antarctic Macquarie Island. Fifty-eight sites in 50 coastal and inland lakes were sampled for benthic diatoms and water chemistry. 208 diatom species from 34 genera were identified. Multivariate analyses indicated that the lakes were distributed along nutrient and conductivity gradients. Conductivity, pH, phosphate (SRP), functions provide a quantitative basis for palaeolimnological studies of past climate change and human impacts, and can be used to establish baseline conditions for assessing the impacts of recent climate change and the introduction of non-native plants and animals. Statistically robust diatom transfer functions for conductivity, phosphate and silicate were developed, while pH and temperature transfer functions performed less well. The lower predictive abilities of the pH and temperature transfer functions probably reflect the broad pH tolerance range of diatoms on Macquarie Island and uneven distribution of lakes along the temperature gradient. This study contributes to understanding the current ecological distribution of Macquarie Island diatoms and provides transfer functions that will be applied in studies of diatoms in lake sediment cores to quantitatively reconstruct past environmental changes.
The download file contains a copy of the referenced paper, plus tables of data collected in the study.
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Start Date: 2006-02-01Stop Date: 2006-04-09
Quality The latitudes and longitudes provided in spatial coverage are approximate only.
Taken from the referenced paper:
Fifty-eight sites in 50 ponds and lakes on the coastal terrace and plateau were sampled during a six week period from February-April 2006. These sites include most ponds and lakes on Macquarie Island. The largest four lakes were sampled at two locations (at the ... western and eastern sides) to try and account for spatial variability in nutrients and conductivity. At each site, surface sediment samples (top 1cm) were collected from about 1 metre water depth using a hand-operated gravity corer (Glew 1991). While there are a few deep lakes on Macquarie Island, most are shallow and only 1-2 metres deep. Consequently, samples were collected from about 1 metre depth throughout the sampling campaign. At each site, surface water conductivity, dissolved oxygen, pH, temperature and turbidity were measured using a Hydrolab Datasonde 4a. Duplicate water samples were collected for soluble reactive phosphate (SRP), nitrate/nitrite and silicate analyses. Sample tubes were rinsed several times in lake water at each site prior to collection. Samples for nutrient analysis were frozen as soon as possible after collection and analysed using an Alpkem Autoanalyzer (Continuous Flow Solution Analyzer) at the Commonwealth Scientific and Industrial Research Organisation Marine and Atmospheric Laboratories, Hobart, in May 2006. The autoanalyser uses the principles of colourimetric analysis in a continuous flow system with all manipulations of the samples automated. Each analytical channel was calibrated using standards of known concentration.
Access Constraints These data are available for download from the provided URL.
Use Constraints This data set conforms to the PICCCBY Attribution License
Please follow instructions listed in the citation reference provided at http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=ASAC_2663 when using these data.
Data Set Progress
Distribution Media: HTTP
Distribution Size: 754 kb
Distribution Format: PDF
Role: TECHNICAL CONTACT
Phone: +61 3 6266 2980
Fax: +61 3 6226 2973
Email: Andrew.McMinn at utas.edu.au
Institute of Antarctic and Southern Ocean Studies University of Tasmania Private Bag 77
Province or State: Tasmania
Postal Code: 7001
Role: TECHNICAL CONTACT
Phone: +41 31 631 50 63
Email: krystyna.saunders at giub.unibe.ch
University of Bern Lake sediment and Paleolimnology Hallerstrasse 12
Postal Code: CH-3012
Role: DIF AUTHOR
Phone: +61 3 6232 3244
Fax: +61 3 6232 3351
Email: dave.connell at aad.gov.au
Australian Antarctic Division 203 Channel Highway
Province or State: Tasmania
Postal Code: 7050
Saunders, K.M., Hodgson, D.A., McMinn, A. (2009), Quantitative relationships between benthic diatom assemblages and water chemistry in Macquarie Island lakes and their potential for reconstructing past environmental changes, Antarctic Science, 21, 1, 35-49, doi:doi:10.1017/S0954102008001442
Creation and Review Dates
DIF Creation Date: 2006-07-27
Last DIF Revision Date: 2011-03-01