Australia is entering a phase of rapid offshore renewable energy development, with several marine regions earmarked for wind farms. Underwater noise generated by the construction and operation of large wind turbines may affect species such as whales that rely on their acoustic environment to feed, breed and survive.
In considering the environmental acceptability of wind energy projects under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act), the Department of Climate Change, Energy, the Environment and Water will need to assess potential risks to the recovery of listed populations. This requires understanding whether there is a threat, the potential impact, and the consequences for population recovery.
The southern right whale and blue whale are listed as Endangered under the EPBC Act 1999. Feeding and breeding areas for these species potentially overlap with some declared areas for wind energy development.
With a focus on the Gippsland and Southern Ocean proposed offshore wind areas, this project will use a risk-based modelling approach to determine the likelihood of impacts that could impede the recovery of southern right whale and blue whale populations. This ‘first-pass’ approach will also consolidate available data, identify and prioritise research needs, and contribute to determining appropriate mitigation measures should the activity proceed.
This desktop study will use available data and expert opinion to develop interim Population Consequences of Disturbance (PCoD) models for blue whales and southern right whales in relation to one or multiple offshore wind farm developments off Portland and Gippsland, Victoria. The interim PCoD method has been used internationally to assess the impacts of offshore wind farm developments, including for harbour porpoises in British waters. The model will follow a decision pathway to consider factors such as:
- when and where development activities overlap with populations;
- the proportion of populations affected;
- the life stages and reproductive phases affected; and
- the chances of repeated disturbance.
The model will be used to predict the timing and location of cumulative impacts of the proposed activity or activities at a regional scale, addressing questions such as:
- which species are at ‘high-risk’ and are a priority for further research;
- noise levels mitigation measures would need to achieve to adequately reduce the risk of compromised population viability;
- what research is needed to better understand population level consequences of noise; and
- which mitigation measures can substantially reduce the risk of population-level effects.
The model will be able to be updated as new data become available. The results will be able to be combined with other modelling approaches such as those developed to predict the effect of a seismic survey on a humpback whale population. They will also be relevant to other ocean-based activities such as oil and gas infrastructure and carbon capture and storage.
The results of this project will contribute to Project 4.7: Development of regional modelling and risk assessments to inform offshore renewable decision-making.
See this story, ‘Who’s talking about offshore wind energy?’, for more detail about the offshore renewable energy licensing and assessment process.
Wind energy regulators and proponents will have improved capability to assess for southern right whales and blue whales the probability of population-level impacts associated with underwater noise attributed to offshore developments. This capability may also assist in species recovery planning, the drafting of national underwater noise guidelines, and decision-making for oil and gas activities including seismic surveys.