Metadata record for data from AAS (ASAC) Project 3261.
The objectives of this project are to:
1. Assess temporal variability in stream invertebrates on the sub-Antarctic island, Macquarie Island. This objective is to support their use as indicators of stream health due to climate change, other anthropogenic impacts and natural changes (see below).
2. Measure for the first time ecosystem ... functions of breakdown of organic matter and ecosystem respiration in streams of Macquarie Island.
3. Collect for the first time samples from the algae and protozoan stream communities from Macquarie Island.
The stream invertebrate communities of Macquarie Island were assumed to be temporally stable. However, sampling of these communities in the summers of 1992/93 and 2007/08 has shown an unexpected change over this period. The cause of this change is unknown. Likewise it is unknown whether this change (a) was a gradual change between the sampling points, (b) the change was abrupt or (c) if there were many changes over this period. Without information on temporal variability on the scales less than a few years it is impossible to assess potential cause of the past observed change in the stream invertebrate communities. We thus propose sampling the stream invertebrate communities in the 2009/10 summer and (if possible) over the 2010 winter. In conjunction with the 1992/93 and 2007/08 data, this new data will allow assessment of the temporal variability of the invertebrate communities at a number of scales.
Objectives 2 and 3 are to provide information of food-webs and the ecology of Macquarie Island streams so as to better understand the natural processes occurring in the stream and to assess the potential for them to be affected by climate change, other anthropogenic impacts and natural changes on the island.
Progress against objectives:
Stream samples (invertebrate and protozoan) were collected from sites 2,3,4,5,6 and 16, and invertebrate only samples from 11 and 18. These samples have been preserved and are returning to Australia on V5 where they will undergo laboratory processing, identification and statistical analysis of the data.
Dissolved oxygen and temperature loggers were installed at three sites and will be left in place until May 2010 (and returned on Voyage E1). From the data collected by these loggers it will be possible to estimate the productivity of the streams (total stream photosynthesis and respiration).
Data from this project have been archived in the Australian Antarctic Data Centre.