We will need a vast expansion in offshore wind to meet Net Zero aims. By 2050, around 630GW of turbines will have been installed, compared to  40GW in 2020. These may have positive impacts on marine biodiversity, but to understand the changes new methods of monitoring will be needed.

Offshore wind farms are crucial in our transition to cleaner energy. Before they can be installed, developers will be asked to complete an environmental impact assessment, and to commit to ongoing monitoring during construction and, often, during operation. This allows developers and leaseholders to understand how their work affects biodiversity. But traditional methods of monitoring—with environmental specialists and ecologists going out to sea—will not be able to keep pace with the surge in installations.

Uncrewed Surface Vessels

Uncrewed surface vessels (USVs) and remotely operated vehicles (ROVs) are increasingly used to perform inspections offshore: in the planning of a wind farm, before construction, and to monitor assets during construction and operation. And they can now be used to monitor marine life, as well as mapping the seabed or checking on turbines.

Dan Smith is the global solution owner for offshore wind site appraisal at Fugro. He believes that the development of USVs or uncrewed surface vessels, designed for asset inspection, could also them to be used for monitoring biodiversity.

“We should try and do more with the vessels that we have. For example, we’ve invested in a project called BeWild, which is under a Dutch subsidy. And that’s to use the USV, which would be used for asset inspection. And we find that actually, it’s better and faster for an offshore wind developer, if you also do your environmental assessments, or your some of your environmental surveys on the same vessel at the same time, because you’ve got one campaign.”

Destructive monitoring

To understand the biodiversity in a certain area of the ocean is not an easy task. The current method involves scientists going out with fishing trawlers and counting what comes up in the catch.

Angela Martinez Quintana is a senior environmental scientist for Fugro, based in the US. She has worked on these trawlers to conduct fish surveys.

“Right now, the methods that they use to quantify fish is trawling. So you have fishing boats that can do 30 or 40 trawls every three months. You have your marine biologists on the boat, they actually sort all the animals on tables, they weigh them, they measure them, it is very time consuming. And it’s a very destructive method. And this is how they are actually doing the surveys for fish.” explains Martinez Quintana.

But to continue to do fish surveys over the lifetime of a wind farm and across the large expanse of ocean they cover, will not be possible. So new technologies are being developed to make this process faster, more remote, and less destructive.

eDNA

One promising method is environmental DNA (eDNA), a groundbreaking solution for measuring biodiversity. Smith explains, “So if you can take a volume of that, of that water, and then you pass it through a particular filter, so that you then end up with basically a sludge, which you can then analyse, it will tell you the presence of different types of species.” 

However, eDNA offers a more efficient and less intrusive alternative. It also has other benefits like its ability to identify species that are more rare in a certain area, which may not be caught by trawlers.

Testing with eDNA also allows for surveys to be far more localised and targeted. Smith emphasises this by stating, “If you want more targeted information—say you want to know what’s right at your foundation—we can take these from our ROV’s because they’ll be right on the location of the foundation, and it will give you that sort of information about the species right there.” 

However, Smith and Martinez Quintanta acknowledge that eDNA is still in its early stages of development and it still has limitations.

Martinez Quintana explains “So environmental DNA is actually very good with certain species, with fish, with marine mammals, and not not as good with certain invertebrates. If you don’t have the genome in a gene database you cannot compare it with the environmental DNA.”

eDNA also is unable to provide information of the number of species in an area or whether that species is currently alive or dead, it can only be used to provide a ‘yes’ or ‘no’ indication to the presence of a species DNA.

Data Processing and AI

eDNA may currently have limitations but it offers a very promising solution to scaling up data collection and monitoring of biodiversity. However even if ROVs equipped with eDNA monitors are able to start collecting data on a large scale, that presents a new challenge for the environmental scientists: processing all that data.

Martinez Quintana explains, “Because you can have very sensitive sensors or very high quality imaging. But if you don’t actually have the manpower to process that information, it doesn’t matter.”

This is where, like many industries, the environmental scientists are turning to AI. “The other process is having AI that is going to help you to go through videos, or through acoustic data, or through images faster to identify a species and to be able to analyse the data faster,” says Martinez Quintana.

Industry wide collaboration

To monitor biodiversity on the scale required is going to take a lot of collaboration throughout the industry. One organisation trying to bring offshore wind developers and environmental scientists together is The Crown Estate.

The Crown Estate is a large public landowner in the UK, with a £16 billion portfolio, The Crown Estate owns virtually all the UK seabed, from the average low water mark out 12 miles into the sea, so before a company can begin constructing a wind farm they have to go through the Crown Estate’s tendering process.

The UK, with over 20 years of offshore wind experience, is actively working on harnessing data for the greater good. Tim Stiven from the Crown Estate explains their efforts in creating a digital twin of the seabed: “For us, what a digital twin means is an ability to understand pretty much any given square kilometre, what is the best use of the seabed given all of those competing purposes?” This comprehensive understanding includes factors like geology, environmental conditions, and installed assets, facilitating informed decision-making.

The Crown Estate also emphasises collaboration within the industry, sharing knowledge and data through initiatives like the Offshore Wind Evidence and Change (OWEC) Programme. Stiven says, “We’re particularly proud to say that we have a leading role globally in helping people access and organise information about the environment.”

Environmental impact assessments are often criticised for slowing down projects, but understanding the impact of wind farms on marine life is crucial for both project improvement and expeditious design processes.

Despite the challenges, the consensus among industry experts is positive. Smith says, “As we’re building these very large projects at a very large scale and a pace that we’ve never really done before, we do need to take the time to make sure that as we do it, we’re understanding what the potential effects are, so that we don’t have unforeseen consequences in the future.”

The journey towards revolutionising offshore wind farm monitoring for biodiversity involves embracing cutting-edge technology, fostering global collaboration, and diligently monitoring the ecological impact. As we navigate this evolving landscape, the goal is not only to harness clean energy but also to ensure a harmonious coexistence with the diverse ecosystems that inhabit our oceans.