Impacts of climate change on marine industries

Table 1 lists the physical and chemical changes likely to be experienced in future.

Table 1. Projected changes in physical and chemical characteristics of Australia's marine area by 2070 from the CSIRO Mk 3.5 model

Physical climate change indicators	Projected climate change impacts by 2070
Sea surface temperature	Waters around Australia will warm by 1-2°C, with greatest warming in SE Australia/Tasman Sea due to strengthening of the East Australian Current.
Temperature at 500 m depth	Warming of 0.5-1°C
Incident solar radiation	There will generally be more incident solar radiation on the sea surface in Australian waters. The increase will be between 2 and 7 W/m².
Mixed layer depth	Almost all areas of Australia will have greater stratification and a shallowing of the mixed layer by about 1 m, reducing nutrient inputs from deep waters.
Surface winds	An increase of 0-1 m/s in surface winds will occur.
Surface currents	A general decline in the strength of surface currents of between 0 and 1.2 m/s is expected.
Ocean pH	A decline in pH by 0.2 units is expected.

Source: Hobday et al., 2006¹

Some of the predicted impacts of climate change on aquatic systems, especially marine systems, have been summarised in the following table.

Table 2. Some likely impacts of climate change on Australia's oceans, coasts and rivers, as exemplified by biophysical change from climate drivers

Variable	Impact
Sea level rise and storms	Rise in sea level from glaciers melting, and increased occurrence or intensity of extreme storms leading to higher risk of inundation and flooding. Shoreline would move toward land as sea level rises; houses built close to the coast could become partly submerged.
Warmer ocean temperatures	Increased frequency of coral bleaching events (present models project the Great Barrier Reef will warm by 2 to 5°C by 2100). Potential impacts on biodiversity by affecting the distribution and reproductive patterns of marine organisms, and consequently food web dynamics (productivity).
Ocean acidification (pH)	Increased CO₂ concentration in sea water is altering ocean chemistry, making it more difficult for organisms which build shells or skeleton from calcium in the water, such as corals and molluscs, to grow and function.
Decreased rainfall and drought	Warmer temperatures will cause greater evaporation, increasing the severity of drought for a given decrease in rainfall.
Increased river temperatures (freshwater)	Warmer temperatures will change species' distributions (food web dynamics), because fish and invertebrates regulate their body temperatures by the surrounding water temperature; when their home is in a constrained area such as a river or lake, they have potentially no cooler water to migrate to.
Run-off changes	Changes in climate over land will cause changes in the way water makes its way to the coast. This may alter the availability and quality of fresh water, which could impact the productivity and ecosystem function of coastal and estuarine environments.
Ocean stability and currents	Changes to wind and water temperature affect water column stratification and stability leading to changes in upwelling of nutrient-rich deeper waters and productivity of surface waters. Changes to ocean currents, notably the East Australian and Leeuwin currents, may affect dispersal and distribution patterns of marine organisms
ENSO weather phenomenon	Some models suggest global warming may lead to an increase in the frequency or intensity of El Niño events. If so, Australia may have more intense droughts and La Niña floods, particularly in the eastern part of the country.
Tropical cyclones and storm surges	Combined with higher sea levels, the projected increase in occurrence and intensity of tropical cyclones would cause more frequent and intense coastal flooding. Tropical cyclones may occur further south than they do at present. Potential shifts in prevailing wind and wave patterns.
Increased fire and wind	Increased occurrence and/or intensity of dust and fire-borne particulates can affect coastal productivity and promote blooms.

Sources:
Australian Greenhouse Office: Hobday & Matear (Eds) 2005², Hobday et al. 2006¹
Bureau of Meteorology³
CSIRO 2007⁴Fisheries Research and Development Corporation⁵Hennessey et al. 2007⁶
World Wildlife Fund⁷

Return to Climate change and fisheries

¹Hobday AJ, Okey TA, Poloczanska ES, Kunz TJ & Richardson AJ (Eds), 'Impacts of climate change on Australian marine life', Report to the Australian Greenhouse Office, Canberra, 2006. www.climatechange.gov.au

²Hobday AJ & Matear R (Eds), 'Review of climate impacts on Australian fisheries and aquaculture: Implications for the effects of climate change', Report to the Australian Greenhouse Office, Canberra, 2005.

³Bureau of Meteorology, 'Climate change', available September 2007 at http://www.bom.gov.au/climate/change

⁴CSIRO, 'Climate change', available September 2007 at http://www.dar.csiro.au/information/climatechange.html

⁵Fisheries Research and Development Corporation, 'Investing for tomorrow's fish: the FRDC's research and development plan 2005 to 2010, FRDC, Canberra. Available September 2007 at http://www.frdc.com.au/about/plan2005-10.pdf

⁶Hennessy K, Fitzharris B, Bates BC, Harvey N, Howden SM, Hughes L, Salinger J & Warrick R, 'Australia and New Zealand - Climate change 2007: Impacts, adaptation and vulnerability', Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, ML Parry, OF Canziani, JP Palutikof, PJ van der Linden & CE Hanson (Eds), 2007, Cambridge University Press, Cambridge UK, pp507-40.

⁷World Wildlife Fund, Climate change (various articles). Available September 2007 at http://www.wwf.org.au/ourwork/climatechange