By Alex Banks, Principal Specialist, Ornithology.
Northern Gannet. © Allan Drewitt, Natural EnglandOffshore wind development is a vitally important part of the UK government approach to tackling the climate crisis and addressing energy security. At the same time, it is also vitally important that we protect and restore our marine biodiversity and enable nature recovery. Both of these things can and should go hand in hand, but in order to get this balance right, we need good information about what lives in our seas and where.
That's where the POSEIDON project comes in.
What is POSEIDON?POSEIDON stands for Planning Offshore Wind Strategic Environmental Impact Decisions. It's a four-year project led by Natural England, as part of the Offshore Wind Evidence and Change Programme (OWEC), led by The Crown Estate in partnership with the Department for Energy Security and Net Zero (DESNZ) and the Department for Environment, Food and Rural Affairs (Defra), which aims to facilitate the sustainable and coordinated expansion of offshore wind to help meet the UK’s commitments to low carbon energy transition whilst supporting clean, healthy, productive and biologically diverse seas.
The goal of the project is to gather detailed information about UK seas to ensure that we are building offshore wind farms in the right places, allowing us to generate clean energy whilst avoiding or minimising risks to wildlife.
Grab sampling by survey contractor Ocean Ecology Limited © Cefas. Why is POSEIDON important?Over the years, information about our marine wildlife and environment has been collected for many different purposes. However, this information is scattered across various different sources, making it difficult to identify gaps in knowledge and resulting in a lack of a comprehensive evidence base that is easy to access and interpret.
POSEIDON was created to help fill these gaps. The team brought together existing information and collected new data to build detailed maps of:
Seabed habitats – the environments on the ocean floor Seabirds – like puffins and guillemots Marine mammals – including minke whales and bottlenose dolphinsHaving a comprehensive evidence base is important as it will help developers and decision‑makers plan more accurately, reduce uncertainty, and focus future surveys where they’re needed most – while simultaneously protecting our marine wildlife.
The new project helps protect marine mammals, such as bottlenose dolphins. © Alan Drewitt, NE How did we collect the data?Over two years, our aerial surveys covered three key regions: the Central North Sea, the South-West Celtic Sea, and the Northern Isles. The team captured images of over 54,000 seabirds and more than 5,000 marine mammals.
Aircraft fitted with special cameras flew over parts of UK waters, taking high-resolution photographs – these Digital Aerial Surveys (DAS) were carried out by the contractor APEM Limited. Experts then analysed these images to identify different species, count them, and record where they were found.
Digital Aerial Survey of the North Sea, February 2023 © APEM Ltd.The work below the sea was led by project partner Cefas (Centre for Environment, Fisheries and Aquaculture Science), and covered five regions: the North Sea, Irish Sea, Celtic Sea, South-West, and English Channel. As part of the data collection, scientists collected samples from the seabed using a method called grab sampling, where equipment lowered from a boat scoops up material from the ocean floor. This helped them understand what habitats exist in different areas.
These surveys, combined with the existing data we collated, gathered an enormous amount of information—covering roughly 750,000 square kilometres for seabirds and marine mammals, and collecting more than 13,000 seabed samples. This is one of the largest efforts ever made to improve our understanding of UK seas for offshore wind planning.
Grab sampling by survey contractor Briggs Marine © Cefas.All the newly collected survey datasets, reports and imagery funded by POSEIDON are now publicly available to download via The Crown Estate's Marine Data Exchange (MDE), the world’s largest collection of marine industry survey data, research, and evidence.
What next?The team is now using all this information to build models and maps showing where species and habitats are most likely to be found, and how sensitive they might be to offshore wind development.
A new online mapping tool will launch in Summer 2026, making it easy for developers, planners, and decision-makers to access this information in one place.
By bringing all this evidence together, POSEIDON is helping the UK build the clean energy we need while protecting our beloved marine wildlife and seas.
seen at 11:04, 4 March in Natural England.