Grey Seal Halichoerus grypus Phenology at Skomer and Marloes Peninsula

The grey seal (Halichoerus grypus) is listed in Annex II of the EU Habitats Directive and is a qualifying feature of three Special Areas of Conservation in Wales. Pembrokeshire colonies represent the largest breeding population in southwest Britain. The aim of this study was to provide evidence on the status of grey seal pup numbers around the Island of Skomer and the Marloes Peninsula, Pembrokeshire, based on over 30 years of survey data collected from 1983-2015. This report quantifies recent population growth, analyses the timing of the pupping season and makes recommendations for the future of this survey. Logistical constraints at the end of the observing season required data modelling to estimate both the mid-point and length of the pupping season.

Identification

Identifier
NRW_DS119129
Alternative Title
  • Ffenoleg Morloi Llwyd Halichoerus grypus yn Sgomer a Phenrhyn Marloes
  • Temporal trends and phenology in grey seal (Halichoerus grypus) pup counts at Marloes Peninsula, Wales
  • Temporal trends and phenology in grey seal (Halichoerus grypus) pup counts at Skomer, Wales
Metadata Language
English
Lineage

Trained staff have conducted over 30 annual surveys from 1983-2015 of grey seal pupping sites. Individual records were kept of each pup’s progress from birth to moult following a standardized protocol. Details included a unique numerical pup identifier, the location (beach name) and date of first observation, and a qualitative assessment of the developmental stage (1-5) of the pup. Sites were visited once a week and pups marked with a unique pattern to help monitor each individual. Records were maintained in field note books and transferred to recording sheets and Excel spread-sheets. Annual reports have been produced, from which the data in this study have been collated. Using R, spatially aggregated counts of pup numbers were analysed and trends in population abundances were quantified by fitting a Generalised Additive Model to the time series of annual pup counts.
Additional Information

Skomer seal report: Bull JC, Börger L, Franconi N, Banga R, Lock KM, Morris CW, Newman PB, Stringell TB. (2017), Temporal trends and phenology in grey seal (Halichoerus grypus) pup counts at Skomer, Wales, NRW Evidence Report No: 217, 23pp, Natural Resources Wales, Bangor. Marloes seal report: Bull JC, Börger L, Banga R, Franconi N, Lock KM, Morris CW, Newman PB, Stringell TB. (2016), Temporal trends and phenology in grey seal (Halichoerus grypus) pup counts at Marloes Peninsula, Wales, NRW Evidence Report No: 155, 23pp, Natural Resources Wales, Bangor.
Dataset Reference Date (Publication)
2017-07-31
Owner
  Natural Resources Wales (NRW)
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
Originator
  Swansea University, Dept. of Biosciences
Singleton Park, Swansea, Abertawe Swansea, SA2 8PP., Wales
http://www.swansea.ac.uk/biosci/#accept
 

Extent

Extent

Geographic Extent
Pembrokeshire (45)
N
W
E
S
Map representing the geographic extent of the dataset


 
 

Distribution

Format Type and Description
  • Delimited ()

    Specification

    Project 478 Temporal trends and phenology in grey seals pup counts - Pembrokeshire (Skomer & Marloes), 2017 Media 1555 Data Outputs for two related reports: NRW Evidence Report 155: [A] Report in PDF Format - held in the DMS in NRW Evidence report area; [B] years and total counts in Microsoft Excel spread-sheet format .XLS - Marloes Peninsula census data.XLSX (EVID-307-372); [C] R script in proprietary format but may be opened as .TXT file - phenology basic analysis marloes.R (EDIV-307-371); NRW Evidence Report 217 [A] Report in PDF Format - held in the DMS in NRW Evidence report area; [B] years and total counts in Microsoft Excel spread-sheet format .XLS - Data_Skomer.XLS (EVID-307-375) and metadata Data_Skomer_Notes.XLS (EVID-307-377); [C] Daily births data in .CSV format - Skomer_daily_births.csv (EVID-307-376); [D] R script in proprietary format but may be opened as .TXT file - skomer analysis.R (EVID-307-373);

 

Quality

Data quality

Quality Scope
Dataset
Conformity
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
Explanation
Degree
false
Lineage

Trained staff have conducted over 30 annual surveys from 1983-2015 of grey seal pupping sites. Individual records were kept of each pup’s progress from birth to moult following a standardized protocol. Details included a unique numerical pup identifier, the location (beach name) and date of first observation, and a qualitative assessment of the developmental stage (1-5) of the pup. Sites were visited once a week and pups marked with a unique pattern to help monitor each individual. Records were maintained in field note books and transferred to recording sheets and Excel spread-sheets. Annual reports have been produced, from which the data in this study have been collated. Using R, spatially aggregated counts of pup numbers were analysed and trends in population abundances were quantified by fitting a Generalised Additive Model to the time series of annual pup counts.
 

Keywords

Keywords

GEMET - INSPIRE themes, version 1.0
Type
Theme

Citation

Date (Publication)
2008-06-01
Code
geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme

Keywords

NRW Thesaurus
  • grey seals
  • halichoerus grypus
  • phenology
  • Skomer (Skomer Island)
  • Marloes Peninsula
  • Pembrokeshire (county pre 1974)( county since 4/96)
Type
Theme

Citation

Date (Publication)
2023-12-31
Code
geonetwork.thesaurus.local.theme.converted_nrw-keywords

Keywords

SeaDataNet Parameter Discovery Vocabulary
  • Seal abundance
Type
Theme

Citation

Date (Revision)
2021-01-06
Code
geonetwork.thesaurus.external.theme.rdf+xml

Keywords

NRW SMNR Vocabulary
  • Animals, Plants and Other Organisms (SMNR)
  • Natural Resources (incl. Features and Processes) (SMNR)
  • Ecosystem (SMNR)
  • Coastal Margins (SMNR)
  • Sustainable Management of Natural Resources (SMNR)
  • Sea and Coast (SMNR)
  • Marine (SMNR)
  • Management Areas (SMNR)
Type
Theme

Citation

Date (Revision)
2023-12-27
Code
geonetwork.thesaurus.local.theme.converted_nrw-smnr-keywords
 

Spatial Reference System

Code
British National Grid (EPSG::27700)
 

Content

Content Information

NRW Profile

Custom Elements

NRW Related Title

Temporal trends and phenology in grey seal (Halichoerus grypus) pup counts at Skomer Wales
NRW Related Title

Temporal trends and phenology in grey seal (Halichoerus grypus) pup counts at Marloes Peninsula Wales
 

Constraints

Constraints

Limitations on Public Access and Use

Restriction type
Other restrictions
 

Access Constraints Directive

Limitations
no limitations
 

Access Constraints Text

Other constraints

There are no access restrictions to this data. NRW may release, publish or disseminate it freely.
 

Use Constraints

Use constraints type
Other restrictions
Other constraints

© CNC/NRW Data may be re-used under the terms of the Open Government Licence providing it is done so, acknowledging both the source and NRW's copyright. It is the recipient's responsibility to ensure the data is fit for the intended purpose.
 
 
 

Metadata

Metadata

File Identifier
4f4c4942-4343-5764-6473-313139313239 XML
Metadata Language
English
Resource type
Dataset
Metadata Date
2024-05-31T09:39:07.399Z
Metadata Standard Name
NRW
Metadata Standard Version

1.0

pointOfContact
  Natural Resources Wales (NRW)
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
 
 

Publishing Body

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