215b377b-fbf1-4955-9875-7c76afaa5666 English series series 2026-08-17T08:39:45 MEDIN 3.1.2 biota Bird counts SeaDataNet Parameter Discovery Vocabulary 2026-06-19 revision Bird taxonomy-related abundance per unit area of surface SeaDataNet Parameter Discovery Vocabulary 2026-06-19 revision Consenting The Crown Estate Renewable Energy Development Phases 2012-05-15 revision Agreement for Lease Area The Crown Estate Renewable Energy Development Areas 2012-05-15 revision Protected sites GEMET - INSPIRE themes, version 1.0 2009-07-31 revision Atmospheric conditions GEMET - INSPIRE themes, version 1.0 2009-07-31 revision Species distribution GEMET - INSPIRE themes, version 1.0 2009-07-31 revision SeaDataNet sea areas 2012-11-07 revision English Channel SeaVoX Vertical Co-ordinate Coverages 2020-05-21 revision atmosphere 2005-01-01T00:00:00 2007-02-28T23:59:59 1.19909862666431 1.28781180307629 51.7045741034085 51.7467490093695 TCE-475 Marine Data Exchange 2005-2007, RSPB, Gunfleet Sands 1 and 2, Environmental survey (Ornithological Studies) Environmental survey (Ornithological Studies) 2006-01-22T00:00:00 creation 2021-05-17T13:38:30 publication English This project consists of survey figures for both boat and aerial surveys which were undertaken to assess the potential impacts of the Gunfleet Sands development. Also included is an impact assessment methodology report for ornithology. Origin: RSPB Eastern England There will be no limitations when published on the Marine Data Exchange otherRestrictions Data Must be used in accordance to the Marine Data Exchange's Terms of Use: https://www.marinedataexchange.co.uk/content/info/terms-of-use otherRestrictions The Crown Estate +44 020 7851 5000 enquiries@thecrownestate.co.uk custodian RSPB wildlife@rspb.org.uk originator The Crown Estate +44 020 7851 5000 enquiries@thecrownestate.co.uk distributor Orsted info@orsted.com owner unknown Documents https://www.marinedataexchange.co.uk/details/TCE-475/summary A link to the web service or dataset. https://www.marinedataexchange.co.uk A link to the general host site. Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services 2010-12-08T00:00:00 publication Conformity with the Commission Regulation (EU) No 1089/2010 was either not relevant to this dataset or not a requirement of the Marine Data Exchange for the creation and submission of this dataset; therefore, conformity has not been assessed and cannot be declared False series erial surveys used for this report were undertaken using a methodology developed by the Danish National Environment Research Institute (NERI) (Kahlert et al. 2000 and further refined by Camphuysen et al. 2004). Aerial surveys were undertaken by the Wildfowl and Wetlands Trust Wetland Advisory Service using experienced observers who have undertaken aerial survey previously in relation to offshore wind farms. Several Partenavia PN68 aircraft were used, flying at an altitude of 250 ft and at a speed of approximately 200 kmh-1. The location of the plane was recorded every five seconds using a GPS. Combining the time at which birds were encountered and the track flown by the plane (which is recorded continuously with GPS), the locations of observed birds can be calculated with considerable accuracy (often to within a few hundred metres). Transects were flown with a spacing of 2 km. Transects were primarily orientated in a north south direction so that they run perpendicular to major environmental gradients (primarily sea depth) and because this orientation reduces the effect of glare during the survey which aids the detectability and identification of birds. A 12m boat was used that allowed observers an eye height above water of 2.2m and was of sufficient draft to enable transects across the Gunfleet sand bank in water of 2m or less depth. The choice of survey date each month was associated with a tidal regime that enabled the dawn or dusk access to and from the berth at Wivenhoe at or near high tide. For safety reasons, transects across Gunfleet Sand coincided with high water and these were restricted to slightly deeper channels. Similarly it was not possible to arrange survey transects in a regular grid perpendicular to the bathymetric/hydrographic features in this sector of the Thames estuary. Thus, during each day’s survey that lasted between 4.5-6.5h for the first nine surveys the boat retraced some of the previous routes. Within the data analysis for sea birds the observations for repeat transects were not used since the survey boat itself could displace individuals on or near the sea surface during a previous transect and under count them or conversely double count the same individuals if they had remained in place. From survey 10 onwards of 5-8h duration there were fewer repeat transects as a wider zone around the development area was covered. However, the nature of the day’s survey transects that are constrained by water depth around the Gunfleet bank will result in a higher probability of double counting species such as Red-throated Diver. The contact rate with land birds and wildfowl and waders in flight included the full survey time and are represented as numbers/h of survey. A 180° scan method was employed up to survey 19 on 3 May 2002 followed by a 90° scan to the present surveys (Komdeur et al. 1992). The three surveys in February 2002 were based on a different vessel of 18m length with an observer eye height of 3m above sea level and covered up to 16km to the northeast of the development area. An experienced member of the 1980-90 European ‘seabird at sea’ team undertook independent verification of the surveyors and their methodology. Orsted Project Manager +45 4517 1022 info@orsted.com pointOfContact EPSG Geodetic Parameter Registry 2022-11-29 revision WGS 84