Assessment of the Impact of Hydraulic Cockle Dredging on the Macroinvertebrate Faunas of Traeth Lafan (1993-1994)
This dataset contains the results of a macroinvertebrate and sediment survey conducted post hydraulic cockle dredging around Traeth Lafan, North Wales. The purpose of this data collection was to study the effects of hydraulic suction dredging on benthic invertebrate macrofaunas, substrate conformation and sediment composition on Traeth Lafan. The survey was located at Traeth Lafan, the northern entrance to the Menai Strait (Menai Strait and Colwyn Bay Special Area of Conservation (SAC)). A survey of the macroinvertebrates and sediments of Traeth Lafan, North Wales, was undertaken following extensive hydraulic cockle dredging in autumn 1993. The survey covered the site allocated for dredging and part of the hand gathering area, which was used as 'control', against which changes on the dredged ground could be compared. A follow up survey, using the same sampling grid and rationale, was carried out twelve months later, in November 1994, to ascertain the recovery state of the area after a full season's recruitment.
- Identification
- Extent
- Distribution
- Quality
- Keywords
- Spatial Reference System
- Content
- Constraints
- Maintenance
- Metadata
Identification
- Identifier
- NRW_DS110069
- Alternative Title
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- 1993-94 CCW Traeth Lafan hydraulic dredging impact survey JNCCMNCR40000693
- Asesiad o effaith cribinio hydrolig am gocos ar ffawna macroinfertebratau Traeth Lafan (1993-1994)
- Metadata Language
- English
- Lineage
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The survey consisted of a widespread survey using a grid of single sample stations and an intensive survey of four stations with replicate sampling, deployed across the dredged area. Both the single survey grid and one replicate station covered an area of 'control' ground allocated to hand gathering. 0.01m-2 x 0.2 sediment cores were collected at each sampling station and surface evidence of deeper burrowing animals was recorded. A sample was taken of the surface sediment for granulometric analysis, substrate shear strength was measured and the presence of other physical features recorded. Samples were sent to the laboratory for analysis. There is a high confidence in this data, however no spatial reference were provided with data for statistical analysis. It is assumed for the purpose of the metadata that samples were collected using Latitude and Logitude (WGS84). The post disturbance ecological survey was carried out on 12th December 2003 and 8th January 2004 with the follow up survey undertaken on the 28th and 29th of December 1994. Confidence in this dataset is high, however no spatial reference were provided with data for statistical analysis. It is assumed for the purpose of the metadata that samples were collected using Latitude and Logitude (WGS84).
- Additional Information
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There is an associated report to accompany this dataset: P.Allen., CCW. 1995 An assessment of the impact of hydraulic cockle dredging on the macroinvertebrate faunas of Traeth Lafan, North Wales CCW Science Report No. 64. Bangor.
- Dataset Reference Date (Publication)
- 1995-03-31
Temporal Extent
- Begin date
- 1993-12-12
- End date
- 1994-12-29
- Topic category
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- Biota
Extent
Extent
- Geographic Extent
- SIR YNYS MON - ISLE OF ANGLESEY
- Geographic Extent
- Wales (WLS)
))
Vertical Extent
- Medin Extent Keyword
- benthic boundary layer
Vertical Extent
- Minimum value (metres)
- 3.5
- Maximum value (metres)
- 3.5
- Vertical CRS
- urn:ogc:def:datum:EPSG::5100 Sea Level depth is unadjusted and does not take into account tidal height
Distribution
- Format Type and Description
-
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Documents
()
- Specification
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[A] Report is held as a .pdf file, data is held as .SAM and .WPS files. [B] Floppy disk 1 398KB (WPS files) [C] Floppy disk 2 575KB (SAM files) [D] Report- scanned copy in PDF format [E] Survey data in Marine Recorder (JNCCMNCR40000693)
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Documents
()
Quality
Data quality
- Quality Scope
- Dataset
- Lineage
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The survey consisted of a widespread survey using a grid of single sample stations and an intensive survey of four stations with replicate sampling, deployed across the dredged area. Both the single survey grid and one replicate station covered an area of 'control' ground allocated to hand gathering. 0.01m-2 x 0.2 sediment cores were collected at each sampling station and surface evidence of deeper burrowing animals was recorded. A sample was taken of the surface sediment for granulometric analysis, substrate shear strength was measured and the presence of other physical features recorded. Samples were sent to the laboratory for analysis. There is a high confidence in this data, however no spatial reference were provided with data for statistical analysis. It is assumed for the purpose of the metadata that samples were collected using Latitude and Logitude (WGS84). The post disturbance ecological survey was carried out on 12th December 2003 and 8th January 2004 with the follow up survey undertaken on the 28th and 29th of December 1994. Confidence in this dataset is high, however no spatial reference were provided with data for statistical analysis. It is assumed for the purpose of the metadata that samples were collected using Latitude and Logitude (WGS84).
Keywords
Keywords
- Type
- Theme
Citation
- Date (Publication)
- 2008-06-01
Keywords
- NRW Thesaurus
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- Lafan sands (Lavan sands)(Traeth Lafan)
- Menai Strait
- cockle dredging (hydraulic dredging)
- macroinvertebrates
- benthic species
- sediments
- marine and freshwater inventory
- Type
- Theme
Citation
- Date (Publication)
- 2023-12-31
Keywords
- SeaDataNet Parameter Discovery Vocabulary
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- Shellfish abundance and biomass in water bodies
- Fishery characterisation
- Sedimentary structure
- Sediment grain size parameters
- Type
- Theme
Citation
- Date (Revision)
- 2021-01-06
Spatial Reference System
Content
Content Information
NRW Profile
Custom Elements
- NRW Related Title
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An assessment of the impact of hydraulic cockle dredging on the macroinvertebrate faunas of Traeth Lafan, North Wales
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 data. CCW may release, publish or disseminate it freely.
Use Constraints
- Use constraints type
- Other restrictions
- Other constraints
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© CCGC/CCW 1995. 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 CCW'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.
Metadata
Metadata
- File Identifier
- 4f4c4942-4343-5764-6473-313130303639 XML
- Metadata Language
- English
- Parent Identifier
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Natural Resources Wales (NRW) Marine Benthic Species and Habitat Collation Held in Marine Recorder
NRW_DS114501
- Resource type
- Dataset
- Metadata Date
- 2024-12-09T12:37:49.341Z
- Metadata Standard Name
- NRW
- Metadata Standard Version
-
1.0