Abstract
Dutch government policy aims at realising sustainable energy production in The Netherlands. One possibility explored is offshore wind power. As an initiative, the government has given permission for the construction of a Near Shore Wind Farm (formerly called NSW, now OWEZ: Offshore Wind farm Egmond aan Zee) as a demonstration project, used for assessing both technological and environmental challenges in relation to construction and operation. In order to evaluate environmental impacts from an offshore wind farm it is necessary to carry out a baseline or T0 study, which provides for a thorough description of the ecological reference (present) situation.
The Nuon-Shell consortium “NoordzeeWind” exploiting the intended wind farm
has procured a baseline study on the North Sea situation. The company has
granted a contract to Alterra (now IMARES), to carry out the baseline study for
harbour seals in the OWEZ area. The objectives of the study are described in the
Strategy of Approach “Assessment of the Reference Situation of the Near Shore
Windpark (NSW) for Harbour Seals”, as referred to in the Framework Agreement
for the Provision of “MEP services” concluded between NSW and Alterra. They
read: to estimate density and habitat use of harbour seals in the target area as
well as reference areas.
The applied techniques to assess density and habitat use have to be of an
internationally recognised standard, and should provide for data sufficient to
describe the reference situation in space and time.
This baseline study includes a description of the spatial distribution, activity and
migration of harbour seals that haul out both north of the OWEZ area (Wadden
Sea) and south of it (Delta area). Seal activity and habitat use is measured by
tagging harbour seals enabling to follow the animals on their trips at sea and
measure diving activity.
When exploring possible effects of offshore wind farms along the Dutch coast,
local effects such as habitat loss through disturbance and physical habitat
change should be considered. In addition attention should be given to possible
changes in the migration from the Wadden to the Delta area. Figure 1 shows a
scheme of the planned study with respect to the effect study for OWEZ. Collection of data at sea will be combined with habitat modelling to estimate the
relative importance of the study area and its possible functions. The basis for the
assessment of possible effects of wind farms in open sea is the field study in
phase two (T1) an evaluation of all collected telemetry data will be made, effects
will be tested in comparison to data collected during the operation of the wind
farm.
Only the baseline data collected during the T0, are presented in this report.
Further analysis will take place after T.