Alien species that could hop between wind turbines and vessels could have ‘extensive’ impact on ecosystems, restructuring food webs and transmitting disease, warns report
Offshore wind farms could help spread alien species that treat turbines like “stepping-stones” and hitchhike on vessels between countries, warns a new scientific report.
The report, a literature review of scientific research on the topic, was published in June by the Norwegian Institute for Water Research, an environmental research organisation.
Alien species are organisms that spread into new areas where they are not naturally found due to human activities.
This can have disastrous consequences. Consider how invasive grey squirrels have all but wiped out red squirrels indigenous to the UK, or how rabbits were transported on ships to Australia, where they exploded in population and have become a nationwide pest.
The report notes the “extensive” impact that alien species can have on ecosystems, including by “restructuring food webs and transmitting disease and genetic material.”
Offshore wind farms represent an “increasing surface area of artificial structures,” it said, continuing that scientific findings “indicate this novel hard habitat could aid the establishment and spread of alien species in new areas”.
Indeed, a recent DNV report found that offshore wind farms could take up 9% of the North Sea basin by 2050.
“Due to this,” the report said there is a need to “assess the potential role that wind farm structures will play in spreading alien species”.
The report, which centred on the possibility of alien species spreading to Norway in particular, found that alien species could:
- Use offshore wind farms as “stepping-stones” to spread to different countries
- Spread by “hitchhiking on vessels” and other offshore wind structures, which could also help them spread to “inshore” areas and ports.
- Spread in range as a result of finding refuge from fishing within offshore wind farms
To combat this, the report called for monitoring and research into the presence of alien species on existing offshore structures and enhancing collaboration between stakeholders and policymakers.
Examples of alien species that offshore wind farms could help spread include barnacles, amphipods, Pacific oysters and crabs. Another species, the Japanese sea squirt, is listed as “high risk” in Norway, the report noted.
The coexistence of offshore wind farms and fisheries is one solution that could be investigated to “evaluate its potential to control the spread of alien and invasive species,” said the report.
It also suggested that vessels could take measures to “avoid contact with areas known to contain invasive species of risk,” as well as advocating the “cleaning of vessels prior to their arrival at farms.”
The issue of “marine alien species fouling offshore structures is not a new one,” noted the report, with other artificial structures having existed for decades in the North Sea. It continued that these existing structures “may help to shed light on immediate actual risks facing native Norwegian habitats.”
