Marine Renewable Energy and Implications for Cetaceans
Currently very little is known about the impacts of marine renewable energy developments on whales, dolphins and porpoises.
The noise from the pile driving process (used in the majority of foundations) has the potential to cause the most harm to cetaceans, including physical injury. The sound of this industrial work can carry for many tens of kilometres under water. At distances of 30-40 kilometres, research has shown that the noise could be strong enough to mask the communication of harbour porpoises and bottlenose dolphins can also be affected behaviourally within this kind of distance.
Limited research that has been conducted so far has shown the potential for offshore wind farms to cause harbour porpoises to leave the area during construction. In some instances they did not later return to their usual numbers. Even where areas have been recolonised, it is not clear if these are the same animals returning or new animals moving into the area.
Other potentially negative impacts include noise both above and below the water, entrapment, entanglement or collision, pollution (e.g. leaks or spills of hydraulic fluid used in various devices, leaks of cargoes or fuel carried by the vessels such as maintenance vessels), changes in prey abundance and distribution.
These impacts are likely to be significantly greater – if placed in sensitive areas for cetaceans such as those used for breeding, nursing, feeding or migration.
It’s not about whether we build them, it’s about where.
The report "Marine Renewable Energy: A Global Review of the Extent of Marine Renewable Energy Developments, the Developing Technologies and Possible Conservation Implications for Cetaceans" is aimed at helping governments, developers and other key parties in the marine renewable energy industry to make the best-informed decisions as to where and how to site their facilities.
It points out that, until the impacts of marine renewable energy developments can be fully assessed and adequately mitigated, further developments that may affect important areas for whales and dolphins must be avoided. This is the responsible and ‘green’ approach to development.
The report recommends minimum research requirements to ensure the needs of whales and dolphins at a site, and throughout their range, are understood and accounted for before construction is allowed to begin. At the same time, further scientific data is needed on the exact effects of developments, for the full range of whale and dolphin species likely to be impacted.