Bureau Waardenburg
Varkensmarkt 9
4101 CK Culemborg
the Netherlands
T: +31 (0) 345 512710
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Monitoring seabirds by aerial surveys in search areas offshore wind energy

The objective for offshore wind energy in the Dutch part of the North Sea is 6,000 MW and for future wind farm developments search areas have been defined. For a proper estimation of the potential ecological impacts of building, exploiting and decommissioning of offshore wind farms, a vast amount of ecological information is required. Gathering ecological information at sea is expensive and takes time. The Dutch government has commissioned a task group of different institutes to develop a 'Masterplan Ecologische Monitoring Lange Termijn Wind op Zee'. The masterplan identified gaps in the knowledge associated with the ecological impact of offshore wind farms, and laid out a plan to fill these gaps. A number of research projects were identified to fill high-priority knowledge gaps, be available even before the first concessions are to be issued, called the Shortlist Masterplan. In 2010-2011 this priority research has been carried out, including an aerial survey program on seabirds conducted by Bureau Waardenburg. 

The report (in English) can be downloaded from the website of the Dutch government (Informatiehuis Marien) or directly via this link. Also the other reports carried out within the framework of the Shortlist Masterplan can be downloaded here.


Masterplan Ecological Monitoring long term offshore wind energy

The aim of the Shortlist Masterplan project is to fill existing knowledge gaps in order to come to a better-informed set of general and location-specific permit requirements for the concessions to be appointed for development of offshore wind farms in the Dutch North Sea. The following high priority knowledge project were assessed; the presence and distribution of fish eggs and larvae, the mortality effect of the sound and pressure waves generated by piling of turbine foundations on larval fish, the spatiotemporal distribution and density estimates of Harbour Porpoises, the distribution of seabirds over the Dutch North Sea (aerial surveys carried out by Bureau Waardenburg), effects of the planned offshore wind farm concessions on breeding Lesser Black-backed Gulls, and measurement of threshold sound intensity at which a Temporary Threshold Shift occurs in harbour porpoises and harbour seals.

Overall findings

With nine aerial surveys in the period May 2010 - April 2011 the aim of the project to gather the first detailed information on densities and distribution of seabirds in the search area for round 2 and 3 wind farms in the Dutch part of the North Sea was achieved. Despite the geographical scale of the area, data were gathered on seabird distribution and behaviour (including feeding, migration and flying heights) in both the search areas for round 2 and 3 wind farms and the wider Dutch North Sea region. Furthermore, this was achieved year-round and for all species deemed important in relation to offshore wind power. Due to the low flight altitude, species identification in the Shortlist Masterplan aerial surveys has proven to be good.



The methodology of the Shortlist Masterplan aerial surveys has proven to fulfil the aim of collecting data on the distributions and occurrence of seabirds in the Dutch North Sea. An initial year's data has been collected and has enabled the detailed distribution patterns and densities of seabirds to be established. In order to strengthen these findings, further surveys are recommended in order to enable the level of variation in seabird distributions throughout the year to be assessed. The importance for seabirds of the search areas for offshore wind farms should be further investigated. Here ship-based surveys could provide additional essential information on the behaviour and flight altitudes of birds within these areas and would ensure a complete assessment of the distribution and densities of seabirds.

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