Re-examination of distribution data for the harbour porpoise (Phocoena phocoena) on the North West European Continental Shelf

The Joint Cetacean Database, contributed to by Joint Nature Conservation Committee (JNCC), Sea Watch Foundation (SWF) and Sea Mammal Research Unit (SMRU) contained most, but not all, effort-related cetacean data for North-west European waters up to 1998. Effort-related data from this database have been used to produce maps of cetacean distributions for north-west European waters for a Cetacean Atlas at the scale of 1/4 ICES (International Council for the Exploration of the Sea) rectangles (c. 25 x 25 km - 625 km2) due to be published by the JNCC. Some initial modelling of distribution data for harbour porpoise had not indicated any discrete areas of concentration. However, the spatial analyses conducted to derive species distributions were at too coarse a scale to detect concentrations. The UK has undertaken to re-examine distribution data for harbour porpoise with a view to site selection for this species. During 2001, a number of new effort-related surveys of harbour porpoise distribution were conducted in Welsh waters. These included: 1) surveys of southern Cardigan Bay with emphasis upon the Special Area of Conservation established for bottlenose dolphins, conducted by Sea Watch Foundation between May and October and funded by EU INTERREG Programme with support from the Countryside Council for Wales (Baines et al., 2002); 2) a parallel acoustic and visual survey of harbour porpoises in South-west Welsh waters with emphasis west of Pembrokeshire, conducted by Chris Pierpoint with support from the International Fund for Animal Welfare (Pierpoint, 2001); surveys of the waters around Bardsey Island and the Llyn Peninsula, North Wales, conducted by Friends of Cardigan Bay and the Whale and Dolphin Conservation Society (WDCS), with support from CCW; and land-based and offshore surveys off the coast of Anglesey, undertaken by Marine Awareness North Wales, also with support from CCW.

Identification

Identifier
NRW_DS109992
Alternative Title
Metadata Language
English
Lineage

Data on porpoise distribution and abundance come from three main sources: Sea Watch Foundation - opportunistic sightings and effort-related recording; SAST The Seabirds at Sea Team of the UK Joint Nature Conservation Committee (JNCC) - at-sea survey data; SCANS (Small Cetacean Abundance on the North Sea) -methodology involved line transects to provide each survey block with even coverage of survey effort within the time available and conditions expected. Data Processing- In order to provide a standardised description of animal distribution, sightings rates are used to describe the perceived density of animals in particular areas. Usually, sightings rates are presented as encounters per km of survey track line, but since many data used here (from the Sea Watch database) were collected by stationary observers from vantage points such as cliff-tops in timed intervals, the number of individuals sighted per unit time was considered to be a more appropriate measure of sightings rate. The only data associated with this project is held within the report.
Dataset Reference Date (Publication)
2005-02-28

Temporal Extent

Begin date
2001-01-01
End date
2001-12-31
 
Topic category
  • Biota
Owner
  Natural Resources Wales (NRW) -
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
Originator
  Sea Watch Foundation -
Head Office, Ewyn y Don, Bull Bay, Amlwch, Ynys Mon, LL68 9SD, Wales
http://seawatchfoundation.org.uk/
 

Extent

Extent

Geographic Extent
Wales (WLS)
N
W
E
S
Map representing the geographic extent of the dataset


 

Vertical Extent

Medin Extent Keyword

water column skin
 
 

Distribution

Format Type and Description
  • Documents ( )

    Specification

    [A] Report (MS Word, PDF-format). [B] Figures included within the report are held as seperate pdf. files.

 

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

This dataset has not been assessed for conformance to the referenced INSPIRE regulation.
Degree
false
Lineage

Data on porpoise distribution and abundance come from three main sources: Sea Watch Foundation - opportunistic sightings and effort-related recording; SAST The Seabirds at Sea Team of the UK Joint Nature Conservation Committee (JNCC) - at-sea survey data; SCANS (Small Cetacean Abundance on the North Sea) -methodology involved line transects to provide each survey block with even coverage of survey effort within the time available and conditions expected. Data Processing- In order to provide a standardised description of animal distribution, sightings rates are used to describe the perceived density of animals in particular areas. Usually, sightings rates are presented as encounters per km of survey track line, but since many data used here (from the Sea Watch database) were collected by stationary observers from vantage points such as cliff-tops in timed intervals, the number of individuals sighted per unit time was considered to be a more appropriate measure of sightings rate. The only data associated with this project is held within the report.
 

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
  • marine and freshwater inventory
  • species distribution
  • areas of concentration
  • distributions
  • site selection
  • phocoena phocoena
  • phocoena phocoena
  • harbour porpoises
  • Sea Mammal Research Unit (SMRU)
  • Special Areas of Conservation (SAC) (see also Candidate Special Areas of Conservation cSAC)
  • porpoises (see also specific species)
  • Cardigan Bay
  • re-examination
  • Joint Nature Conservation Committee (JNCC)
  • Sea Watch Foundation (SWF)
Type
Theme

Citation

Date (Publication)
2026-08-27
Code
geonetwork.thesaurus.local.theme.converted_nrw-keywords

Keywords

SeaDataNet Parameter Discovery Vocabulary
Type
Theme

Citation

Date (Publication)
2024-06-19
Code
geonetwork.thesaurus.external.theme.rdf+xml
 

Spatial Reference System

Code
British National Grid (EPSG::27700)
 

Content

Content Information

NRW Profile

Custom Elements

NRW Related Title

Re-examination of distribution data for the harbour porpoise on the N.W. European continental shelf with a view to site selection for this species
 

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 dataset. 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
4f4c4942-4343-5764-6473-313039393932 XML
Metadata Language
English
Resource type
Dataset
Metadata Date
2026-09-28T11:42:10.845Z
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

Access the portal