Surveying pelagic fish for offshore wind farm developments

What needs to be considered for offshore wind farm development?

As part of the process to gain government approval to build an offshore wind farm in Australia, there are various environmental studies that need to take place.

These studies inform environmental impact assessments – a measure of a development’s potential impact on habitats and species in the area.

It’s both a privilege and a huge responsibility to map the marine environment as accurately as possible so developers can amend designs or undertake mitigation measures to ensure construction and operation of an offshore wind farm will have minimal impacts.

So, the question every developer and regulator must decide: what marine environmental surveys are needed? And, depending on the location of future offshore wind farms, I believe, there’s a strong case for including pelagic fish surveys when assessing the environmental impacts of a project.

Why survey pelagic fish – and what are they?

New methods to survey pelagic fish

Pelagic fish can be tricky to survey – they can cover large distances, move in an out of areas and swim at various depths. They are also unpredictable! This renders many traditional survey techniques redundant. So, in February this year, I – along with my RPS colleagues, scientists from Deakin University and local charter fishers took to the waters off the Gippsland coast in Victoria to trial a new method for studying pelagic fish. This approach could be readily repeated at relatively low cost, and by using local vessels.   

The survey was for Australia’s most advanced offshore wind project, Star of the South, and co-funded by the Victorian Government’s Energy Innovation Fund. Star of the South has been leading the way in supporting numerous studies to understand the marine environment off the Gippsland coast.

Over two weeks in February, we used a combination of technology and techniques to capture data. This included specially designed underwater video cameras fitted with bait and reflective mirrors to attract and identify species, line fishing to gather biological information, and echo-sounders to more broadly characterise the pelagic fish life at each site.

Recruiting local fishers to help pinpoint the best areas to work in was invaluable, given their local knowledge of fishing in the area.

The survey allowed us to trial the techniques, refine our methods, and gather data to build on existing knowledge.

On the positive…

When engaging with the local community in the Gippsland region, recreational anglers and commercial fishers offered their thoughts about the potential benefits of introducing turbines. This provided another reason to survey the area.

They believe offshore wind farms will increase the abundance of pelagic fish, a bonus for those who enjoy fishing. This is consistent with observations overseas, where wind farms have created new habitats for some marine species.

We know the important contribution offshore wind farms will have for achieving net zero targets in Australia. The farms will also create social, recreational, and economic opportunities too. It’s important to cast the net wide – so to speak – when assessing the impacts of wind farms off our coastline.

The big picture