Indicator: AAT-10 seal populations
Data
Population estimates of Southern Elephant Seals at Macquarie Island
Source: Department of the Environment and Heritage 2006, Indicator 31 - Annual population estimates of Southern Elephant Seals at Macquarie Island, viewed 1 Jul 2006, http://aadc-maps.aad.gov.au/aadc/soe/display_indicator.cfm?soe_id=31
What the data mean
The data to date show that the number of breeding cows on Macquarie Island have been declining at about 1.2% per year for the last decade. This indicates that the large ocean environment that the seals forage in (the whole Southern Ocean between Macquarie Island and Antarctica and west to Heard Island and east to the Ross Sea) is becoming less and less suitable for foraging by Southern Elephant Seals. It seems likely that present changes in ocean circulation in this huge area have resulted in reductions of plankton stocks to squid and myctophid fish (the major prey groups of Southern Elephant Seals) in accessible foraging areas for the seals compared to previous decades. There has been no appreciable and current competition between Southern Elephant Seals and fisheries in the Southern Ocean to date. Thus the seal decrease is attributable to ‘natural causes’ which can not at this stage be identified.
Data Limitations
Nil specified
Issues for which this is an indicator and why
Australian Antarctic Territory — Environment - Marine ecosystems
Seal populations can act as an indicator of the impact of various factors. Populations are related to resource availability (breeding space and food), behavioural mechanisms (immigration/emigration and breeding effort/success) in addition to climate change and human impacts (fisheries, tourism, pollution, disturbance).
Other indicators for this issue:
- AAT-08 Plankton populations
- AAT-09 Seabird populations
- AAT-11 Whale populations
- CO-02 Number of marine species that are endangered or threatened and changes in population/ distribution of selected threatened species
- BD-02 Conservation status of nationally significant species and ecological communities, compared with previous years
- BD-04 Listed threatened species or ecological communities for which recovery action is showing stable or increasing populations
Biodiversity — Species, habitats and ecological communities - Conservation status of species and ecological communities
Seal populations are related to resource availability (food), behavioural mechanisms (immigration/emigration and breeding effort/success) in addition to climate change and human impacts (fisheries, tourism, pollution, disturbance), and are an indicator of pressures on biodiversity in the AAT and in the world’s oceans more generally.
Other indicators for this issue:
- BD-02 Conservation status of nationally significant species and ecological communities, compared with previous years
- BD-04 Listed threatened species or ecological communities for which recovery action is showing stable or increasing populations
- IW-30 Macroinvertebrate condition
- IW-31 Fish - Abundance and distribution
- IW-32 Frogs - Abundance and distribution
- IW-33 Abundance and distribution of waterbirds
- CO-01 Trends in selected groups of coastal and marine species and habitats
- CO-02 Number of marine species that are endangered or threatened and changes in population/ distribution of selected threatened species
- CO-16 Status of Australian fisheries
- LD-01 The proportion and area of native vegetation and changes over time
- AAT-08 Plankton populations
- AAT-09 Seabird populations
- AAT-11 Whale populations
- AAT-12 Changes in colonies of plants on Heard Island
Seal populations are related to resource availability (food), behavioural mechanisms (immigration/emigration and breeding effort/success) in addition to climate change and human impacts (fisheries, tourism, pollution, disturbance), and are an indicator of the condition of biodiversity in the AAT and in the world’s oceans more generally.
Other indicators for this issue:
- CO-01 Trends in selected groups of coastal and marine species and habitats
- CO-02 Number of marine species that are endangered or threatened and changes in population/ distribution of selected threatened species
- BD-02 Conservation status of nationally significant species and ecological communities, compared with previous years
- BD-04 Listed threatened species or ecological communities for which recovery action is showing stable or increasing populations
- AAT-08 Plankton populations
- AAT-09 Seabird populations
- AAT-11 Whale populations
- AAT-12 Changes in colonies of plants on Heard Island
Coasts and Oceans — Condition of the ocean and coastal waters - Condition of species, habitats and ecosystems
Seal populations are related to resource availability (food), behavioural mechanisms (immigration/emigration and breeding effort/success) in addition to climate change and human impacts (fisheries, tourism, pollution, disturbance), and are an indicator of the condition of biodiversity in the AAT and in the world’s oceans more generally.
Other indicators for this issue:
- CO-01 Trends in selected groups of coastal and marine species and habitats
- CO-02 Number of marine species that are endangered or threatened and changes in population/ distribution of selected threatened species
- BD-02 Conservation status of nationally significant species and ecological communities, compared with previous years
- BD-04 Listed threatened species or ecological communities for which recovery action is showing stable or increasing populations
- AAT-08 Plankton populations
- AAT-09 Seabird populations
- AAT-11 Whale populations
Further Information
Key
Links to another web site
Links to data in the DRS
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