How seabirds respond to disturbance in the North Sea

During his childhood, Poot often spent his holidays on the island of Texel, where his fascination for birds first arose. This led him to dedicating his career to understanding and helping to protect seabirds and coastal birds. Poot has noticed a heightened impact on seabirds in the North Sea. But how birds respond to increasingly intensive disturbances and why they do what they do has not yet been well mapped out, in his opinion.

Offshore wind farms are perhaps the most visible change in the North Sea. And this visibility is only going to increase. In 2024, there were 670 wind turbines in the Dutch part of the North Sea. By 2050, if everything goes to plan, this number will rise to around 5,000. However, apart from theoretical calculations and models, actual insights into the impact of wind turbines on seabirds are lacking. This needs to change, and will do partly thanks to the BirdSafe project. In this project, Poot and his colleagues are currently working with TNO (the Netherlands Organisation for Applied Scientific Research) to study how birds act in proximity to wind turbine blades. “Using thermal cameras, which are a better technique than radar, we can monitor the rotor area during the day, when we mainly see seabirds, and at night, when we mainly see migrating birds, particularly songbirds. This allows us to determine whether, when and how many birds are killed. Or we may find that more birds than expected manage to avoid the rotors at the last moment.”

On the commission of Rijkswaterstaat (the Dutch administrative body for infrastructure and water management), the University of Amsterdam has used sea-based weather data and radar measurements to create a model to predict mass bird migration across the North Sea. “This mass migration actually takes place over just a few peak nights per year”, Poot explains. “Birds only cross the sea when the wind is favourable, and then they all cross at once in the millions.” This model and the bird migration expertise team (comprising bird experts and ecologists including Poot) predict whether birds will migrate across the North Sea en masse 48 hours in advance. Poot: “The two predictions are independently sent to the Ministry of Economic Affairs and grid operator TenneT. If both the model and we as experts expect a peak, the wind turbines are paused. That leaves enough time to still procure alternative energy.”

However, the idea that most birds fall victim to turbines during peak migration is still just a hypothesis, explains Poot. “We simply don’t know for sure. With the BirdSafe project, we primarily hope to find an answer to this crucial question.”

Disturbances in the underwater world can also impact seabirds. Take the example of prawn fishing, which has partly been decommissioned in the coastal zone along the North Sea and in the Wadden Sea due to high fuel costs. Despite this, the impact of the remaining ships is still a concern, especially for species such as the black scoter, which lives in the coastal zone and feeds on small shellfish. It is generally assumed that these birds fly away when ships enter their territory because they are timid. But Poot doubts this. “Scoters have very sensitive beaks that they use to feel for shellfish on the sea floor, which they then directly gobble up while under the water. My hypothesis is that the underwater noise of ships interrupts this process, meaning that they can no longer find food efficiently in those areas.”

Guillemots, i.e. penguin lookalikes that are prevalent in the North Sea, go so far as to avoid offshore wind farms. “In late summer, large numbers of guillemots take off from the British coastal cliffs and swim to our part of the North Sea”, says Poot. “But from monitoring, we can see that the concentration around wind farms is lower than elsewhere. We still don’t know why that is. Underwater noise could also play a role for this species. Not only from the wind farms themselves but also due to the fact that ships, including fishing boats, have to navigate around these wind farms. This results in a concentration of disruptive underwater noise in a greater area than just directly around the wind farms.”

To find answers to these sorts of questions, a number of larger research projects will be carried out over the coming years, involving several research institutes and other organisations. In addition to BirdSafe, there is the North Sea POWER project, funded by the Nationale Wetenschapsagenda (Dutch National Science Agenda). As part of a broad consortium, scientists at Wageningen Marine Research are zooming in on the potential repelling impact of wind farms on seabirds.

To be able to study the birds without disturbing them, drones are now deployed. These offer possibilities that were unheard of until recently, argues Poot. “In March 2026, we flew various types of drones over the coastal zone around the island of Ameland to study scoters. If you fly the drones hundreds of metres above the birds, they don’t notice them. You can then see all sorts of behaviours that you wouldn’t normally be able to see from a boat, as it would be too disruptive. You also can’t see such behaviours from a plane that flies overhead in two seconds.”

Studies such as this one will provide more insights into the impact of human activity on seabirds over the coming years. And according to Poot, that is the key to limiting the negative effects of all new developments on nature as much as possible, as well as to achieving better protection for bird diversity. “It is a good example of applied research that is fuelled by fundamental ecological knowledge.”