e99c36c8-330a-4e9a-9342-1aa5c01d867f English series series 2026-03-17T14:47:38 MEDIN 3.1.2 biota oceans Seal abundance SeaDataNet Parameter Discovery Vocabulary 2023-12-12 revision Seal reproduction SeaDataNet Parameter Discovery Vocabulary 2023-12-12 revision Post-Construction monitoring The Crown Estate Renewable Energy Development Phases 2012-05-15 revision Renewable Energy Lease area The Crown Estate Renewable Energy Development Areas 2012-05-15 revision Species distribution GEMET - INSPIRE themes, version 1.0 2009-07-31 revision SeaVoX Vertical Co-ordinate Coverages 2020-05-21 revision unknown 2015-06-16T00:00:00 2016-07-16T00:00:00 -0.0816 0.5912 52.7909 53.1623 TCE-3520 Marine Data Exchange 2015-2016, SMRU Consulting, Dudgeon, Report on the distribution and abundance of harbour seals (Phoca vitulina) during the 2015 and 2016 breeding seasons in The Wash Report on the distribution and abundance of harbour seals 2024-09-02T16:25:16 publication English This report presents the results of a series of aerial surveys of the harbour seal population along the English east coast between Donna Nook in Lincolnshire and Scroby Sands off the Suffolk coast during the breeding seasons from 16th June to 17th July 2015 and 19th June to 16th July 2016. - Five surveys were completed on the 16th, 21st and 27th June and 3rd and 17th July 2015. - Five surveys were completed on the 19th, 24th June and 2nd, 8th and 16th July 2016. - As usual, flights were restricted to weekends because of RAF range activity. Poor weather conditions on the weekend of 10th July 2015 prevented flying and delayed the final flight to the 17th July 2015. This had no negative effects on the results. - The highest count obtained in 2015 was 1351 on 27th June and in 2016 the highest count was 1580 on 2nd July. Examination of the series of counts suggests that this is close to the actual maximum number of pups for the season. Examination of the five survey counts in each year suggests that these are close to the actual maximum number of pups in each year. - The 2015 count was substantially lower (22%) than the 2014 equivalent count, but the 2016 peak count was 17% higher than in 2015. These wide fluctuations are not unusual in the long term time series. - Despite the apparently wide inter-annual variation, the pup production has increased at around 7.4% p.a. since surveys began in 2001. - The distribution of pup counts within The Wash has changed with more pups in the sheltered South East corner, and more along the banks of the main river channels. These changes appear to have happened between 2001 and 2010. - Pup productivity has apparently increased relative to the independent estimates of the total population size 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 Sea Mammal Research Unit (SMRU) +44 (0)1334 462630 smru@st-andrews.ac.uk originator The Crown Estate +44 020 7851 5000 enquiries@thecrownestate.co.uk distributor Sea Mammal Research Unit (SMRU) smru@st-andrews.ac.uk owner notPlanned Documents https://www.marinedataexchange.co.uk/details/TCE-3520/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 Essentially the survey method is a continuous visual inspection of all potential haulout sites around the coast on off-shore tidal banks. When groups of more than two or thee seals are spotted they are photographed. High resolution, large images are required because of the difficulty in differentiating harbour seal pups from similar sized juveniles and differentiating juvenile grey seals from adult harbour seals. As a consequence large numbers of photographs are required to cover large groups. All photography was conducted obliquely using a CANON EOS SLR camera with 18 to 270mm zoom lens. All surveys followed standard SMRU survey methods and routes and were flown in a twin engine Piper PA-23, 'Aztec' based in Kent. The entire coast is searched from a variable height of 180 to 400m. When groups of seals are sighted the aircraft either flies parallel with the shore for groups of seals spread along open stretches of beach, or performs one or more tight turns to circle smaller or more evenly dispersed groups. Groups hauled out along creeks or dispersed in the salt marsh areas were first identified during intensive visual searches by the 3 man crew and then photographed. This method produces extremely convoluted survey tracks making it difficult to keep track of which groups and sites have been covered. To avoid missing or over-counting groups we maintain three separate records of the survey track. GPS tracks were recorded from the aircraft's on-board GPS logger sampling at 5 second intervals and a GARMIN FORETREX 401 GPS logger sampling at 3 second intervals. The timestamp of the loggers were synched with the time on the camera. Discrete haul-outs can therefore be associated with precise locations and temporal and spatial haul-out patterns can be analysed. Both the cameraman and the observer/tracker recorded the locations and frame numbers directly onto maps and maintained a separate written log of the flight. The number of discrete groups of harbour seals ranged from 44-60 and few were observed at sites other than those previously recorded in the survey area, during the pupping surveys (Figure 6). Additional, solitary animals were counted but not photographed. Example photographs of a range of group sizes are presented in Figure 7 and Figure 8. John Mitchell The Crown Estate +44 020 7851 5000 enquiries@thecrownestate.co.uk pointOfContact EPSG Geodetic Parameter Registry 2021-03-18 revision OSGB36 / British National Grid