Equinor and Norwegian Research Centre (NORCE) have completed a pilot study using environmental DNA (eDNA) to monitor the biodiversity and abundance of marine life in waters around the 30 MW Hywind Scotland floating offshore wind farm.
The pilot study took place in August 2021, at Equinor’s Hywind Scotland offshore wind farm, located 25 kilometres east of Peterhead in Scotland.
The fieldwork was conducted by NORCE with support from Ocean Science Consulting (OSC). After the samples were taken, lab work was undertaken to analyse the samples using polymerase chain reaction (PCR) DNA sequencing.
A similar-sized reference area, located approximately 10 kilometres east of the wind farm, was also sampled to give comparative results. Five stations in each area were sampled at 10 m and 50 m depths. The samples were immediately filtered and preserved on board, kept dark and cool to reduce eDNA decay prior to analysis.
By analysing the eDNA content in water samples, Equinor and NORCE were able to measure the biodiversity of fish species in the water surrounding Hywind Scotland. This pilot study was conducted to learn more about the potential effects that floating offshore wind farms may have on marine habitats.
In the study, it was identified that there were in total 26 fish species in the area. There was no significant difference in biodiversity observed between the wind farm area and the reference zone, however, the relative abundance of sprat and herring were at the time of sampling higher in the wind farm area, said Equinor.
There was also a faint eDNA signal from harbour porpoise recorded in the waters surrounding the wind farm, according to the press release.
An often-used strategy to gather data on fish biodiversity is to employ specialised boats to trawl with fishing vessels through a region at regular intervals to collect and analyse the fish, in combination with echo sonars to identify and calculate the quantity of fish.
The method used in this study negates this issue, said Equinor, utilising DNA content contained in the water, reducing the disturbance to the marine environment, and lowering CO2 emissions.
“ By reducing the need for traditional trawling campaigns , we can help to protect the environment and reduce emissions, while still gathering reliable and accurate data on the species in the area. The potential for this method to be used in other areas of marine biology research is vast, and I look forward to seeing further advancements in this area in the future “, said Kari Mette Murvoll , Principal Researcher at Equinor.