Oil contamination of gannets and their nests on Grassholm subsequent to the sea Empress oil spill.

  • English
  • wel
  • All

Grassholm, situated 23 km WNW of the entrance to Milford Haven, supports the worlds third largest gannetry with an estimated population of 30,000 pairs. Gannet nests are perennial constructions 30-60 cm high, built out of seaweed, grass and items of floating debris collected from the sea. Almost all gannet nests, therefore, contain man-made materials, often in substantial quantities. Dataset contains results of investigations to assess whether nest material contaminated with oil from the Sea Empress was incorporated into gannet nests on Grassholm and, if so, whether there was any effect on fertility or productivity in contaminated nests. At the time of the Sea Empress incident it is estimated that 80 percent of the adult breeding population of gannets on Grassholm had returned to the colony. On a ship based survey between the 25-29/2/96, immediately after the spill, only 0.39 percent of 1,279 gannets recorded showed some degree of oiling, and a similar percentage were observed carrying nest material. The small proportion carrying nest material suggests that at that time they had not started nest building.

Identification

Dynodydd
Identifier
NRW_DS110121
Teitl Amgen
Alternative Title
  • Halogi huganod a'u nythod ag olew ar Ynys Gwales yn sgil gollyngiad olew'r Sea Empress
Laith Metadata
Metadata Language
English
Lineage

Oiling rate of adult gannets within the colony was determined by scoring approximately 1000 birds in a subsection of the colony. Oil contamination was taken as any visible oil spot. Counts were made using binoculars on the 7/4/96, 12/5/95 and 9/4/97 (Bullock/RSPB, 1998). A measure of productivity obtained by scoring approximately 1000 nests. Success was defined as the production of a live offspring i.e. that an egg hatched. For the purposes of a 'site' control, ten samples were obtained in May 1996 from nests on St Kilda, the worlds largest gannetry, situated approximately 60 km west of the Outer Hebrides and 700 km NNW of Grassholm. Samples from Grassholm were collected on the 8/11/96. Nest piles were cut in half vertically and approximately 30-50 cm3 of material removed from the upper 5cm.subset of 14 samples of nest material were selected for this preliminary study, focusing on failed nests on Grassholm (7 samples) in order to determine in the first instance whether PAHs and paraffins would be detectable in the nest material. Three samples from successful nests on Grassholm were included for comparison, in addition to four samples of nest material from the remote location of St Kilda. Extracts were analysed by GC/MS, using standards to quantify range of PAHs and long-chain hydrocarbons. Extraction efficiency for each of the analytes was determined by extraction of spiked samples. Increased monitoring effort and impact assessment following the Sea Empress oil spill. The only data associated with this project is held within the report.
Dyddiad cyfeirnod y set ddata (Cyhoeddiad)
Dataset Reference Date (Publication)
1998-01-31
Perchennog
Owner
  Natural Resources Wales (NRW)
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
Cychwynnwr
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

Hyd
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

Fformat - Math a Disgrifiad
Format Type and Description
  • Documents ()

    Specification

    Report (MS Word, pdf-format)

 

Quality

Ansawdd Data
Data quality

Cwmpas Ansawdd
Quality Scope
Dataset
Dataset
Cydymffurfiad
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

Oiling rate of adult gannets within the colony was determined by scoring approximately 1000 birds in a subsection of the colony. Oil contamination was taken as any visible oil spot. Counts were made using binoculars on the 7/4/96, 12/5/95 and 9/4/97 (Bullock/RSPB, 1998). A measure of productivity obtained by scoring approximately 1000 nests. Success was defined as the production of a live offspring i.e. that an egg hatched. For the purposes of a 'site' control, ten samples were obtained in May 1996 from nests on St Kilda, the worlds largest gannetry, situated approximately 60 km west of the Outer Hebrides and 700 km NNW of Grassholm. Samples from Grassholm were collected on the 8/11/96. Nest piles were cut in half vertically and approximately 30-50 cm3 of material removed from the upper 5cm.subset of 14 samples of nest material were selected for this preliminary study, focusing on failed nests on Grassholm (7 samples) in order to determine in the first instance whether PAHs and paraffins would be detectable in the nest material. Three samples from successful nests on Grassholm were included for comparison, in addition to four samples of nest material from the remote location of St Kilda. Extracts were analysed by GC/MS, using standards to quantify range of PAHs and long-chain hydrocarbons. Extraction efficiency for each of the analytes was determined by extraction of spiked samples. Increased monitoring effort and impact assessment following the Sea Empress oil spill. The only data associated with this project is held within the report.
 

Keywords

Allweddair
Keywords

GEMET - INSPIRE themes, version 1.0
Math
Type
Theme
Theme

Dyfyniad
Citation

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

Allweddair
Keywords

NRW Thesaurus
  • Celtic Sea oil developments
  • oil pollution
  • gannets
  • sula bassana (morus bassana)
  • nests
  • Grassholm
  • Sea Empress
  • pollution (see also specific types of pollution eg. oil pollution)
  • marine and freshwater inventory
  • oil contamination
  • fertility
  • oil derived hydrocarbons
  • polycyclic aromatic hydrocarbons (PAHs)
  • long chain paraffins
Math
Type
Theme
Theme

Dyfyniad
Citation

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

Allweddair
Keywords

SeaDataNet Parameter Discovery Vocabulary
  • Bird reproduction
  • Bird taxonomy-related abundance per unit area of surface
Math
Type
Theme
Theme

Dyfyniad
Citation

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

Allweddair
Keywords

Integrated Public Sector Vocabulary
  • oil spillage
  • productivity
Math
Type
Theme
Theme

Dyfyniad
Citation

Dyddiad (Adolygu)
Date (Revision)
2013-04-03
Code
geonetwork.thesaurus.external.theme.subjects
 

Spatial Reference System

Code
British National Grid (EPSG::27700)
 

Content

Gwybodaeth Cynnwys
Content Information

Proffil CNC
NRW Profile

Elfennau CNC
Custom Elements

NRW Related Title

Oil contamination of gannets and their nests on Grassholm subsequent to the sea Empress oil spill
 

Constraints

Constraints

Limitations on Public Access and Use

Math o Gyfyngiad
Restriction type
Other restrictions
Other restrictions
 

Access Constraints Directive

Limitations
no limitations
 

Access Constraints Text

Other constraints

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

Use Constraints

Cyfyngiadau Defnyddio
Use constraints type
Other restrictions
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

Dynodydd Ffeil
File Identifier
4f4c4942-4343-5764-6473-313130313231 XML
Laith Metadata
Metadata Language
English
Math o adnodd
Resource type
Dataset
Dataset
Dyddiad Metadata
Metadata Date
2024-05-31T09:41:15.748Z
Enw Safonol Metadata
Metadata Standard Name
NRW
Fersiwn Metadata
Metadata Standard Version

1.0

Pwynt Cyswllt
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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