Pressures affecting Antarctic marine species

Component
Summary
Grade
Very high impact High impact Low impact Very low impact
Confidence
In Grade In Trend
Comparability
To previous years

The responses vary among species, and range from increases in metabolic rates (positive effects) to decreases in growth rates (negative effects)

Year(s): 
2016
3
Stable
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Comparable

Primary production by some species may increase up to 19%, but overall increase is likely to be small

Year(s): 
2011
3
Stable
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Concentrations of nutrients and rates of calcification will decrease, causing changes in microbial composition, production and nutritional value

Year(s): 
2016
3
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Comparable

Concentrations of nutrients and rates of calcification will decrease, causing changes in microbial composition, production and nutritional value

Year(s): 
2011
3
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Interspecies differences in response, but can reduce production, slow growth, limit survival and change species composition. In conjunction with ocean acidification, an increase in UVB radiation will potentially alter microbe assemblages

Year(s): 
2016
3
Stable
Confidence (in grade): 
Adequate
Confidence (in trend): 
Adequate
Comparability (to previous reports): 
Comparable

Interspecific differences in response but can reduce production, slow growth, limit survival and change species composition

Year(s): 
2011
3
Deteriorating
Confidence (in grade): 
Adequate
Confidence (in trend): 
Adequate
Comparability (to previous reports): 
Not assessed

Surface warming may increase stratification, increase exposure to UVB radiation, reduce surface nutrient supply and change interactions among key species, causing changes in microbial composition and production. A latitudinal shift in productivity is predicted. There is also increased potential for the invasion of non-native species

Year(s): 
2016
3
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Comparable

Surface warming may increase stratification, increase exposure to ultraviolet B radiation, reduce surface nutrient supply and change interactions among key species, causing changes in microbial composition and production. A latitudinal shift in productivity is predicted. There is also increased potential for invasion of alien species

Year(s): 
2011
3
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Sea ice extent is highly variable and regional differences exist. Decreases in sea ice may reduce microbial food available to grazers (e.g. krill), but extensive sea ice can have adverse effects on the breeding success of seabirds

Year(s): 
2016
0
Unclear
Confidence (in grade): 
Low
Confidence (in trend): 
Low
Comparability (to previous reports): 
Not assessed

Regional differences exist. Decreases in sea ice may reduce microbial food available to grazers (e.g. krill) and carbon dioxide draw-down; altered light climate will favour earlier, weaker blooms

Year(s): 
2011
0
Unclear
Confidence (in grade): 
Low
Confidence (in trend): 
Low
Comparability (to previous reports): 
Not assessed

Thinning alters the light regime; higher light intensities may reduce productivity of light-sensitive species. Changes in seasonality may lead to mismatch for zooplankton and higher consumers

Year(s): 
2016
0
Unclear
Confidence (in grade): 
Low
Confidence (in trend): 
Low
Comparability (to previous reports): 
Comparable

Thinning alters the light regime; higher light intensities may reduce productivity of light-sensitive species

Year(s): 
2011
0
Unclear
Confidence (in grade): 
Low
Confidence (in trend): 
Low
Comparability (to previous reports): 
Not assessed

Currents along the frontal zones increase the risk of exposure to marine debris for seabirds. Microplastics are of particular concern and may be more widespread in the Southern Ocean than expected. Deposition of marine debris, particularly plastics, can lead to ingestion by, and entanglement of, seabirds and seals. Negative impacts on chicks are also possible, because ingested debris may leach harmful chemicals

Year(s): 
2016
3
Deteriorating
Confidence (in grade): 
Limited
Confidence (in trend): 
Limited
Comparability (to previous reports): 
Not assessed

Persistent organic pollutants and inorganic pollutants from local and external sources exist; some are expected to increase and may have direct and indirect toxic effects on Antarctic organisms

Near the stations, the impact is localised and comes mainly from old tip sites

Year(s): 
2016
3
Unclear
Confidence (in grade): 
Adequate
Confidence (in trend): 
Adequate
Comparability (to previous reports): 
Comparable

Persistent organic pollutants and inorganic pollutants from local and exogenous sources exist; some are expected to increase and may have direct and indirect toxological effects on Antarctic organisms Near the stations, the impact is localised and comes mainly from old tip sites

Year(s): 
2011
3
Unclear
Confidence (in grade): 
Adequate
Confidence (in trend): 
Adequate
Comparability (to previous reports): 
Not assessed

UVB = ultraviolet B

Klekociuk A, Wienecke B (2016). Antarctic environment: Pressures affecting Antarctic marine species. In: Australia state of the environment 2016, Australian Government Department of the Environment and Energy, Canberra, https://soe.environment.gov.au/assessment-summary-710-pressures-affecting-antarctic-marine-species, DOI 10.4226/94/58b65b2b307c0