Seabirds in the Dutch North Sea: background document for a protection plan for seabirds potentially vulnerable to offshore wind farms

In the North Sea Agreement, the Parties have agreed to develop protection plans for species and habitats that are most vulnerable to the development of offshore wind energy, that need protection in general, as agreed in international frameworks or that are crucial for nature restoration and improvement. Each protection plan has two parts: a background document and an action plan. The background document brings together and evaluates current scientific information. The action plan contains the measures that the Dutch government, i.e. the Ministries of Agriculture, Fisheries, Food Security and Nature and of Infrastructure and Water Management could take, after consultation with stakeholders of the North Sea Agreement. The current report is the background document for the nature conservation plan: seabirds. This report provides and evaluates information for seabirds related to the following aspects: species descriptions, current conservation status, monitoring and research, assessment of threats, impacts and opportunities, existing national and international conservation measures, knowledge gaps and possible actions. For different groups of seabirds, this is done on the basis of “flagship species” within that group. For the group of “fish eaters foraging at the water surface” this is the northern fulmar; for the “gulls” these are lesser black-backed gull and common gull; for the “skuas” these are great skua and parasitic jaeger; for the “terns”: these are the Sandwich tern and the common tern; for the “(deep) diving species further offshore” these are common guillemot, razorbill and Atlantic puffin and for the “species that dive to the sea floor for food in the coastal waters”, these are red-throated diver and common scoter. The species that are considered in this report can also be classified in other ways, of which two are used: seabirds that breed in the Netherlands and species that only pass through or winter in Dutch waters, and species for which the Netherlands is of international importance and species for which this does not apply. Our country has the most action perspective and responsibility for its own breeding birds: breeding colonies can be (better) protected and the possibilities for breeding can be improved and expanded. Our country does not have these options for species that only breed elsewhere, other than by supporting international initiatives to this end. This also applies to species that visit the Netherlands in relatively small numbers (relative to the total European population). These species may certainly encounter problems in our waters, but these will be no different from other species for which the Netherlands can do more here. Furthermore, all seabirds will benefit from generic measures. All things considered (Table 6), the Netherlands can be most effective with measures aimed at its own breeding birds (lesser black-backed gull, common gull, Sandwich tern, common tern) and for the species that winter in our waters in internationally important numbers (the two coastal species red-throated diver and common scoter, and for the two offshore species guillemot, razorbill).At the end we have selected those priority measures that have sufficient action perspective. This is a combination of the technical feasibility and policy options for Dutch authorities and the expected effectiveness in improving the ecological situation for the bird population considered. The following actions with the highest “action perspective” have come out of our evaluation: For bird species breeding in the Netherlands (lesser black-backed gull, common gull, Sandwich tern, common tern): • Maintain and enhance existing breeding sites; • Create new / alternative breeding sites; • Active control of predators locally (e.g. shooting); • Reduce access to colonies for predators (water surrounding, (electric) fencing); • In case of an outbreak of avian influenza immediately remove dead birds in the breeding colonies. For the two coastal bird species red-throated diver and common scoter: • Creating disturbance-free zones, by closures of high bird density and food base areas within the coastal zone, under real time closure scenarios, for shipping and fisheries. This measure is expected to be effective and manageable. Determination of this measure requires further research into the intensity and type of disturbance (recreational boats, fishing vessels, cargo ships, dredgers, etc.); • Fill knowledge gaps on bycatch by study and monitoring especially for red-throated diver Depending on the outcome, a measure can then also be linked to this research. For the two most abundant offshore bird species (common guillemot and razorbill) together several knowledge gaps exist, the most potential effective measures are: • Avoid building new wind farms in key areas of these two types. An important question is where and when key areas are located in the Dutch part of the North Sea and how resistant they are; • Research into ecosystem effects caused by climate change and changing human use of the sea. Depending on the outcome, a measure can then also be linked to this research. For the four offshore bird species northern fulmar, great skua, parasitic jaeger, Atlantic puffin there is no action perspective for Dutch authorities, except international collaboration and coordination, although for Northern fulmar and Atlantic puffin, attention can be paid to the maintenance and creation of sufficient rest and feeding areas in certain parts of the Dutch North Sea.