Details of MEP-NSW Demersal fish


Dataset identification

Title of datasetMEP-NSW Demersal fish
Narrative summary of datasetThe main purpose of this sampling was to study the effects of the OWEZ windpark on the demersal fish community. Because before installation of the windfarm the main fisheries activity in the area was bottom trawling, it is expected that exclusion of fisheries in the wind farm has the largest effect on the demersal fish community. The wind farm and its safety zone could function as a refugium for these species. If the area functions as a refugium this could be the case for a large number of demersal fish species that occur in the Dutch coastal zone. Owing to this a positive effect of the wind farm on the demersal fish community was expected. The fisheries that occurred in the area targeted larger fish, therefore fisheries mortality was higher on the larger fish. By excluding fisheries in the farm it was expected to change the size distribution in the farm and by that the age distribution of the fish populations. A Hydrolab minisonde, attached to the net, was used for continuous CTD measurements.
Summary of processing methodologyAs in the baseline study, two 6 m beam trawls were used for our study with the vessel GO58 "Jakoriwi". On one side of the ship, we used a beam trawl with a 40 mm net also used in an annual coastal survey (SNS; since 1969). Because this gear catches a low number of smaller fish, a fine meshed net (with 20 mm in the bag) was used on the other side of the ship. This net is used in another annual survey (DFS; since 1970) but has to be attached to a heavy beam to keep the ship in balance. Therefore, the catches with the larger meshsized net are fully comparable to the SNS, whereas catches with the fine meshed net are not fully comparable to the DFS. Length frequency distributions from both nets show that they are complementary, and thus provide a good description of the demersal fish population (Grift & Tien, 2003). The same procedure as in the SNS was followed to make catches from the baseline study comparable to the SNS data, meaning the towing speed was 6.5 km hr (3.5 knots) over the ground, and each haul lasted 15 minutes.
Project/programmeMonitoring Offshore Windfarm Egmond aan Zee
Start date2011-01-01
End date2011-12-31

Responsible organisations

Organisation nameNoordzeeWind BV
Role of organisationOriginator of Dataset
Organisation nameRijkswaterstaat Water, Traffic and Environment
Role of organisationOriginator of Dataset
Organisation nameDeltares
Role of organisationDataset Holding Organisation

Dataset availability

Original dataset download link
Date of original dataset publication2018-03-09
Dataset formatDelimited
Public accessNo limitations
License for useCC0 1.0
Link to dataset after processing by data centre


Latitude north boundary52.73
Longitude east boundary4.583
Latitude south boundary52.42
Longitude west boundary4.16
Coordinate reference systemWorld Geodetic System 84
Sea areaNorth Sea

Data types, collection and processing

Observation typeFish
ParameterFish taxonomy-related counts
Instrument typebeam trawls
Platform typeship
Platform nameJakoriwi

Process information

Submitting organisationDeltares
Submission identifier (UUID)fe8f6f7e-54ab-4aaa-8847-7a58d0552a94
Date of dataset creation2011-12-31
Date of metadata creation2017-11-07
Date of metadata latest revision2018-02-27
Date of publishing2018-02-26
Date of processed dataset publication2021-02-04
Processing data centreDeltares
Summary record-ID67