The North Sea is one of the most industrialised marine environments on the planet, with thousands of MMS including oil and gas platforms, pipelines, subsea cable routes, and marine renewable energy installations. However, the impact of MMS on ecosystems is unclear. To ensure effective decision-making about removal and installation of such structures in the future, there is an urgent need to better understand the impact of MMS on the North Sea ecosystem.
The EcoSTAR project aimed to uncover the impacts of MMS on marine ecosystems, by mapping existing windfarms and oil and gas infrastructure, and measuring the impacts of MMS from the bottom of the food chain (the benthic community) all the way to the top (marine mammals).
EcoSTAR focused on three key research areas:
Video:Foraging seals hunt around wind farms
Recent research, building on Stadler et al. (2022), found no strong link between offshore structures and porpoise behaviour in parts of the North Sea with fewer platforms. Seal activity varied by region but some individuals did show changes near these structures or repeated visits (see video below). These insights help us understand how top predators might respond to man-made environments. For species that live on the seabed, those living closer to platforms expressed fewer traits (traits are the measurable biological features of organisms, including aspects of their morphology, physiology, behaviour, and phenology), suggesting higher functional vulnerability and therefore changes in how the ecosystem works.
Diet assessments through stomach and faecal sample analysis, allows us to understand what the animals ate and helps us to determine local fish availability in time and space. EcoSTAR estimated seal and harbour porpoise distribution in UK and Irish waters using tracking data, habitat models, and haul-out counts. Meanwhile, harbour porpoise distribution was modelled using data from a number of large-scale cetacean surveys. Both sets of information can help to predict how changes in offshore structures (MMS) might affect the abundance of predators and prey.
Existing databases on offshore structures in the North Sea were found to be incomplete and sometimes inaccurate. To address this, researchers created a new, more reliable dataset by combining data from multiple sources. As of mid-2024, the North Sea hosts around 700 oil and gas platforms and over 5,000 wind turbines—emphasising the need to plan carefully for their future removal.
A detailed ecosystem model, Ecopath with Ecosim model, was updated (and is available for download) to better represent marine mammals and expanded to include more areas. Using input from experts and stakeholders, researchers developed future scenarios — including climate change, and fisheries management — to explore how these changes might affect marine life and fisheries.