Implications for marine biodiversity fisheries and aquaculture

A changing climate will impact on the water and food sources that support aquatic life.

The Marine Climate Change Impacts and Adaptation Report Card for Australia provides a guide for industry, scientists, government and the community on the observed and projected impacts of climate change on marine ecosystems. The report card was developed by leading marine scientists from across Australia. Some of the key findings include:

1. Australian ocean temperatures are likely to be 1 degree warmer by 2030 and 2.5 degrees warmer by the end of the century.
2. There has been a 30 per cent increase in hydrogen ion (acid) concentration in oceans since 1750 and this is associated with the amount of carbon dioxide absorbed.
3. The southward flow of the East Australian Current has strengthened so that warmer, saltier water is now found 350 kilometres further south compared with 60 years ago.
4. Global sea levels increased by 20 centimetres between 1870 and 2004.
5. Declines of over 10 per cent in growth rates of massive corals on the Great Barrier Reef are likely due to ocean acidification and thermal stress.
6. Loss of algal habitat off eastern Tasmania associated with a southward range expansion of a sea urchin has been assisted by the strengthening of the East Australian Current and warmer  temperatures.
7. Expansion of sub-tropical species, into south-eastern waters is driven by warming and a strengthening of the East Australian Current.
  8. Annual & ten year mean sea surface temperature for the Australian region. Source: Bureau of Meterology 2010

Resource managers need to appreciate change is here and they need to put in place adaptive strategies to deal with it.

Fishing and aquaculture is subject to uncertainty due to the effects of climate change. For fish populations these may include changes to the abundance and productivity of species and their distribution. Certain species may also be affected by changing weather patterns. Fisheries activities may be affected by conditions that make fishing and aquaculture less predictable and cause greater market volatility.

The FRDC's research is endeavouring to monitor and predict the changes occurring as a result of climate change. Part of this is the development of possible future scenarios for management to evaluate. Early detection of changes to species abundance, and an understanding of their underlying causes coupled with adaptive harvest strategies can ensure Australia’s wild harvest fisheries maintain their pre-eminent sustainability credentials.

Around Australia, fishing businesses are assessing their future with climate change in mind. The Tasmanian Atlantic Salmon industry has initiated a research program to examine how to farm fish in warmer waters. This includes selective breeding of heat tolerant fish or farming fish in cooler waters offshore.

Similarly, northern fisheries reliant on Barramundi and prawns understand they will need to contend with a more variable climate and the effects of more variable rainfall patterns. Stock populations are likely to boom during wetter seasons and be greatly reduced in drier years.

More variable freshwater flows to estuaries and tidal interchanges will also influence habitats and this will alter the distribution of wetland plants and aquatic organisms. Estuarine areas suitable for oyster culture and habitats for crustaceans and juvenile stages of finfish will be effected.

The FRDC has funded and continues to fund research to better understand and address climate change.