Life at sea is under pressure in many places but may be less so around our Danish North Sea platforms. Researchers from DTU Aqua and Aarhus University EcoScience are now gathering critical environmental and biodiversity data to better understand the role of the platforms in attracting marine life. The findings will contribute to the future protection of biodiversity around offshore platforms.
A team of researchers and specialists from TotalEnergies and consulting company DHI has successfully concluded a three-week biodiversity research expedition in the Danish North Sea. The mission involved collecting seabed samples from several offshore platforms operated by the Danish Underground Consortium (DUC) and retrieving 12 underwater sensors that were placed at the Skjold field last summer. The project, a collaborative effort between TotalEnergies, DUC, DTU Offshore, DTU Aqua, and Aarhus University EcoScience, also saw the deployment of four new sensors at the Tyra, Harald, Dan, and Skjold fields.
“The underwater sensors, so-called hydrophones, record the behavior of tagged cod and echolocating marine mammals such as harbor porpoise around our offshore platforms. This helps us better understand the role our platforms play as feeding and spawning grounds for marine life. The preliminary results from our initial study show that the closer you move to the platforms, the more fish you will find, and the larger they are,” says Senior Scientist Jon C. Svendsen, DTU Aqua.
In addition to the data already collected, the newly deployed sensors across different oil and gas platforms will provide further insights into the distribution of cod and harbor porpoises at various locations.
“In the second phase of the study, we broadened the scope from one offshore field to four fields. This will help us to provide insights into the movement of the tagged cod and whether harbor porpoises use other similar platforms. We are positive that the quality of the data collected will fill important scientific knowledge gaps to be used both in the oil and gas, as well as the wind industry,” says Professor Jonas Teilmann at the Department of EcoScience at Aarhus University in Roskilde.
Offshore platforms as reef habitats
Offshore platforms, many of which have been in operation for over 30 years, have contributed not only to energy security but also to marine biodiversity by providing spawning and feeding grounds for marine life. As these structures approach decommissioning, new research emphasizes the importance of considering their environmental impact.
“When planning for decommissioning, platform owners, authorities, and policymakers must consider the marine environmental impact of removing the offshore structures. Growing evidence suggests that platform legs provide reef habitats for fish and marine mammals, so it is important that we collect a solid data foundation to make informed decisions,” says Charlotte N. Larsen, Program Manager at DTU Offshore - Danish Offshore Technology Center.
In the coming months, the analysis of data collected from the recently deployed sensors will continue, with retrieval expected by the end of the year, marking the conclusion of this field campaign.
"The North Sea is the home of our Danish operations, so it is crucial we understand the marine life around our platforms. We are pleased and proud to collaborate with skilled researchers and experts to gain valuable knowledge about the environment and biodiversity trends around platforms. The data guides our decisions relating to activities at sea, and our hope is that the wider society, including industry, authorities, and policymakers can also benefit from it," says Katrina Povidisa-Delefosse, Senior Environment Advisor at TotalEnergies Denmark and PhD in Marine Biology.
In a move to enhance public access to environmental data, TotalEnergies, along with DUC partners BlueNord and Nordsøfonden, and DHI, will launch the North Sea Environment Portal. This platform, set to go live in the fourth quarter of 2024, will offer access to more than 30 years of data on environmental and biodiversity trends.
“The many surveys undertaken by DHI and TotalEnergies with DUC over the years enabled a deep understanding of the development of seabed chemistry and the invertebrate fauna at and around the platforms. The long-term data allows us to study trends in seabed chemistry and the composition and number of invertebrate species including mussels, snails, and bristle worms. Notably, the data shows an increase in the number of invertebrate species over time,” says Senior Project Manager and Biologist Jesper Goodley Dannisøe from DHI.
