The Abundance and Distribution of Waterfowl Within Milford Haven After the Sea Empress Oil Spill

This study was put in place to assess whether the oil spill was to impact the nationally important waterfowl populations found in the area of Milford Haven.


Two polluted (Angle Bay and Pembroke River) and two relatively unpolluted 'control' sites (the Carew/Cresswell and Cleddau Rivers) were monitored intensively over the three winters after the oil spill. The four sites have been monitored following standard Wetland Bird Survey (WeBS) methodology to assess the numbers of waterfowl present, and following standard British Trust for Ornithology all-day (across the tidal cycle) count methodology to assess the feeding areas most used. The data was captured to assess the impact of the Sea Empress oil spill on waterfowl populations in the Milford Haven area.


Counts during winter took place between November and March as the estuary is most important for birds during the winter period. The migration and early autumn periods have been excluded because numbers of birds can fluctuate widely from year to year, for reasons not associated with the estuary. Each site was counted twice a month with one count on a spring tide and one on a neap tide where possible. In the first year, only one count was carried out at each site in November. Historical data was used from 1982-1999.

Identification

Identifier
NRW_DS110120
Metadata Language
English
Lineage

This study monitored the use made by waterbirds of intertidal areas in the Cleddau Estuary over three winter seasons, in relation to oiling levels. Four sites were studied:

- a heavily oiled site, Angle Bay;

- a moderately oiled site, Pembroke River, and

- two effectively non-oiled sites, the Carew/Cresswell rivers and the 'Upper Cleddau', where the Eastern and Western Cleddau meet.


The species recorded include divers, grebes, cormorants, herons, wildfowl, waders and auks. In order to monitor all species comprehensively, an area of open water was also counted at each site. In order to gain a full picture of the use of the four intertidal areas by waterfowl and other birds, counts were carried out across the tidal cycle. This choice of methodology allows the most important feeding areas to be identified. Each site was counted once every hour from six hours before to five hours after low tide. Increased monitoring efforts and impact assessment following the Sea Empress oil spill.
Dataset Reference Date (Publication)
2000-10-31
Owner
  Natural Resources Wales (NRW) -
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
Originator
  Countryside Council for Wales (CCW) -
Countryside Council for Wales, Maes y Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW
http://naturalresourceswales.gov.uk/splash?orig=/
 

Extent

Extent

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


 

Vertical Extent

Medin Extent Keyword

benthic boundary layer
 
 

Distribution

Format Type and Description
  • Documents ( )

    Specification

    [A] Report (MS word, pdf-format, WordPerfect)

 

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

This study monitored the use made by waterbirds of intertidal areas in the Cleddau Estuary over three winter seasons, in relation to oiling levels. Four sites were studied:

- a heavily oiled site, Angle Bay;

- a moderately oiled site, Pembroke River, and

- two effectively non-oiled sites, the Carew/Cresswell rivers and the 'Upper Cleddau', where the Eastern and Western Cleddau meet.


The species recorded include divers, grebes, cormorants, herons, wildfowl, waders and auks. In order to monitor all species comprehensively, an area of open water was also counted at each site. In order to gain a full picture of the use of the four intertidal areas by waterfowl and other birds, counts were carried out across the tidal cycle. This choice of methodology allows the most important feeding areas to be identified. Each site was counted once every hour from six hours before to five hours after low tide. Increased monitoring efforts and impact assessment following the Sea Empress oil spill.
 

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
  • waterfowl
  • Milford Haven
  • oil pollution
  • pollution (see also specific types of pollution eg. oil pollution)
  • Sea Empress
  • abundance
  • river Pembroke
  • Wetland Bird Survey (WeBS)
  • marine and freshwater inventory
  • Angle Bay
  • river Cleddau
  • distributions
  • Carew and Cresswell Rivers
  • British Trust for Ornithology (BTO)
Type
Theme

Citation

Date (Publication)
2025-01-08
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

Keywords

IPSV Subjects List
  • Oil spillage
Type
Theme

Citation

Date (Publication)
2020-11-18
Code
geonetwork.thesaurus.external.theme.subjects
 

Spatial Reference System

Code
British National Grid (EPSG::27700)
 

Content

Content Information

NRW Profile

Custom Elements

NRW Related Title

The abundance and distribution of waterfowl within Milford Haven after the Sea Empress oil spill, year 1 report
 

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 1997. There are no use restrictions on this data. Recipients may re-use, reproduce, disseminate this data free of charge in any format or medium, provided they do so accurately, acknowledging both the source and NRW's copyright, and do not use it in a misleading context. It is the recipient's responsibility to ensure the data is fit for the intended purpose, that dissemination or publishing does not result in duplication, and that it is fairly interpreted. Advice on interpretation should be sought where required. To avoid re-using old data, users should periodically obtain the latest version from the original source.
 

Attribution Statement

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 copyright of the owners. It is the recipient's responsibility to ensure the data is fit for the intended purpose.
 
 
 

Metadata

Metadata

File Identifier
4f4c4942-4343-5764-6473-313130313230 XML
Metadata Language
English
Resource type
Dataset
Metadata Date
2026-03-03T14:27:56.469Z
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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