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
- Extent
- Distribution
- Quality
- Keywords
- Spatial Reference System
- Content
- Constraints
- Maintenance
- Metadata
Identification
- Identifier
- NRW_DS109992
- Alternative Title
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- Ailarchwilio data dosbarthiad ar gyfer y llamhidydd ar Ysgafell Gyfandirol Gogledd Orllewin Ewrop
- Metadata Language
- English
- Lineage
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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
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- Biota
Extent
Extent
- Geographic Extent
- Wales (WLS)
))
Vertical Extent
- Medin Extent Keyword
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water column skin
Distribution
- Format Type and Description
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Documents
Documents
()
- Specification
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[A] Report (MS Word, PDF-format). [B] Figures included within the report are held as seperate pdf. files.
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Documents
Documents
()
Quality
Data quality
- Quality Scope
- Dataset
- Lineage
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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
- Type
- Theme
Citation
- Date (Publication)
- 2008-06-01
Keywords
- NRW Thesaurus
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- distributions
- species distribution
- harbour porpoises
- phocoena phocoena
- porpoises (see also specific species)
- phocoena phocoena
- Joint Nature Conservation Committee (JNCC)
- Special Areas of Conservation (SAC) (see also Candidate Special Areas of Conservation cSAC)
- Cardigan Bay
- site selection
- Sea Watch Foundation (SWF)
- Sea Mammal Research Unit (SMRU)
- areas of concentration
- re-examination
- marine and freshwater inventory
- Type
- Theme
Citation
- Date (Publication)
- 2023-12-31
Keywords
- SeaDataNet Parameter Discovery Vocabulary
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- Cetacean abundance
- Type
- Theme
Citation
- Date (Revision)
- 2021-01-06
Keywords
Spatial Reference System
Content
Content Information
NRW Profile
Custom Elements
- NRW Related Title
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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
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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
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© 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
- 2024-05-31T09:42:59.472Z
- Metadata Standard Name
- NRW
- Metadata Standard Version
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1.0