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Distribution of seabirds on the Belgian Continental Shelf [Verspreiding van zeevogels op het Belgisch Continentaal Plat]

Archived data

Archived file:
Availability: Restricted
The data are withheld from general circulation and disclosure but access may be obtained on a case-by-case basis through negotiation

Notes: Release with permission of the appropriate parties

Description
INBO conducts standardised ship-based surveys since September 1992.Until 2001 this was done from public ferries and the RV Belgica.Since 2001,three fixed monitoring-routes were counted each month from the RV 'Zeeleeuw' (e.g. Seys, 2001). more

To determine the distribution, numbers and densities of seabirds in the BPNS, the data collected between September 1992 and December 2004 were analysed. Additionally, the data from the counts in 2005 were used to determine the species-diversity (see further). Thus, the compiled dataset does comprise data of standardised counts that are well distributed both temporally (both between years and within years) and spatially on the BPNS. Both swimming and flying birds were counted by a standardised strip-transect-method (Tasker et al., 1984). All swimming birds that are within a distance of 300 m and in an angle of 90° forward from the study-vessel were counted in intervals of 10 minutes. Flying birds were counted using a snapshot method (Komdeur et al., 1992). All flying birds within a distance of 300 m and an angle of 90° forward from the study-vessel were counted every minute. In order to compensate for missed small and dark birds, the mean density of swimming birds has been multiplied with an internationally accepted correction factor (Stone et al., 1995). The results of these counts were transformed into densities by taking into account the speed of the research-vessel. All counts were reduced to the spatial mid points of the concerned 10-minute tracks. These midpoints were called position keys or ‘poskeys’ and are displayed in the dataset in degrees northern latitude and eastern longitude and hold the local densities of all species (number per square km). If the ship changed its course within a 10-minute count, the counts relate to a shorter period. To avoid that counts in very short periods of time would bias the calculation of bird densities, all poskeys in which less than 1 km was covered were omitted. Since ferry counts may result in an underestimation of the densities of certain species (e.g. alcidae and divers) because of the higher speed and the height of the observation platform, the data collected from ferries were not retained in the processed dataset. After these selections, data of 10.808 poskeys were retained. For the calculation of the number of species per 3x3 km-square all counts (also counts from ferries and those of 2005) were used (15.908 poskeys)

Scope
Themes:
Biology, Biology > Birds
Keywords:
Marine, Birds, Birds (marine), Marine birds, ANE, Belgium, Belgian Continental Shelf (BCS), Alca torda, Aves, Fulmarus glacialis, Gavia, Larus argentatus, Larus canus, Larus fuscus, Larus marinus, Larus minutus, Melanitta nigra, Morus bassanus, Podiceps cristatus, Rissa tridactyla, Stercorarius skua, Sterna hirundo, Sterna sandvicensis, Uria aalge

Geographical coverage
ANE, Belgium, Belgian Continental Shelf (BCS) [Marine Regions]

Temporal coverage
January 1992 - December 2004

Taxonomic coverage
Alca torda Linnaeus, 1758 [WoRMS]
Aves [WoRMS]
Fulmarus glacialis (Linnaeus, 1761) [WoRMS]
Gavia [WoRMS]
Larus argentatus Pontoppidan, 1763 [WoRMS]
Larus canus Linnaeus, 1758 [WoRMS]
Larus fuscus Linnaeus, 1758 [WoRMS]
Larus marinus Linnaeus, 1758 [WoRMS]
Larus minutus Pallas, 1776 [WoRMS]
Melanitta nigra (Linnaeus, 1758) [WoRMS]
Morus bassanus (Linnaeus, 1758) [WoRMS]
Podiceps cristatus (Linnaeus, 1758) [WoRMS]
Rissa tridactyla (Linnaeus, 1758) [WoRMS]
Stercorarius skua (Brunnich, 1764) [WoRMS]
Sterna hirundo Linnaeus, 1758 [WoRMS]
Sterna sandvicensis Latham, 1787 [WoRMS]
Uria aalge (Pontoppidan, 1763) [WoRMS]

Parameters
Seabird density Methodology
Seabird density: Transect-method (Tasker et al., 1984)
Ref.: Tasker, M.L., P.H. Jones, T.J. Dixon & B.F. Blake (1984). Counting seabirds at sea from ships: a review of methods employed and a suggestion for a standardized approach. Auk 101: 567-577.
The ship counts were done by the so-called Transect-method (Tasker et al., 1984), for which all swimming birds were counted within a 300 m range from the ship and in an 90° angle from the front of the ship, and this during consecutive periods of 10 minutes each
De scheepstellingen werden verricht volgens de zogenaamde transect-methode (Tasker et al., 1984), waarbij gedurende opeenvolgende periodes van 10 minuten alle zwemmende vogels worden geteld die zich binnen een afstand van 300 m van het schip en in een hoek van 90° vanaf de voorkant van het schip bevinden.

Seabird density: Snapshot-method (Tasker et al., 1984)
Ref.: Tasker, M.L., P.H. Jones, T.J. Dixon & B.F. Blake (1984). Counting seabirds at sea from ships: a review of methods employed and a suggestion for a standardized approach. Auk 101: 567-577.
The Snapshot-method (Tasker et al., 1984). is used for the standardized counts of flying birds. All birds flying in a 300 by 300 meters quadrant in front of ths ship are counted every minute. These counting results can be converted to seabird densities by taking the speed of the shipe into account.
Voor het gestandaardiseerd tellen van vliegende vogels is de snapshot-methode gehanteerd (Tasker et al., 1984). Hierbij worden iedere minuut alle vliegende vogels geteld die zich binnen een kwadrant van 300 op 300 meter aan de voorkant van het schip bevinden. De resultaten van deze tellingen kunnen via de snelheid van de boot worden omgerekend naar dichtheden van zeevogels.

Contributors
Vlaamse overheid; Beleidsdomein Leefmilieu, Natuur en Energie; Instituut voor Natuur- en Bosonderzoek (INBO), moredata owner
Vlaamse overheid; Beleidsdomein Leefmilieu, Natuur en Energie; Instituut voor Natuur- en Bosonderzoek; Afdeling Biodiversiteit en Natuurlijk Milieu; Onderzoeksgroep Ecosysteemdiversiteit, moredata creator

Related datasets
Parent dataset:
European Seabirds at Sea - data collected by the Research Institute for Nature and Forest (INBO), Belgium, more
(Partly) included in:
AS-MADE: Assessment of Marine Debris on the Belgian Continental Shelf: occurrence and effects, more

Project
AS-MADE: Assessment of Marine Debris on the Belgian Continental Shelf: occurence and effects. - AS-MADE, more
BIOMARE: Implementation and networking of large-scale long-term marine biodiversity research in Europe, more

Publication
Based on this dataset:
Stienen, E.W.M.; Van Waeyenberge, J.; Seys, J.; Offringa, H.; Meire, P.; Kuijken, E. (2002). Seabirds in Belgian marine waters: implications for policy and management (poster), in: Mees, J. et al. (Ed.) VLIZ Young Scientists' Day, Brugge, Belgium 13 March 2002: book of abstracts. VLIZ Special Publication, 7: pp. 43, more

Dataset status: Completed
Data type: Data
Data origin: Research
Metadatarecord created: 2005-12-20
Information last updated: 2010-11-05
All data in IMIS is subject to the VLIZ privacy policy