Llyn Tegid Hydroacoustic Surveys and Gwyniad Translocations 2004-2009

  • English
  • wel
  • All

The gwyniad (Coregonus lavaretus) population of Llyn Tegid has been considered for a number of years to be threatened by deteriorating environmental conditions, especially those associated with eutrophication. This dataset contains the results of a project established in 2004 to carry out translocation, hydroacoustic surveys and measurement of environmental variables. The purpose of this data capture was to consider the implications for the status of gwyniad (Coregonus lavaretus) and its habitat in Llyn Tegid. The objectives of the project include both conservation actions and further research, including the establishment of a refuge population in Llyn Arenig Fawr. Surveys were carried out annually from 2004 - 2009. Following a first unsuccessful translocation attempt in 2003, three successful translocations have taken place- in early 2005, 2006 and 2007. A full fish population survey of the recipient site of Llyn Arenig Fawr was undertaken in 2009.

Identification

Dynodydd
Identifier
NRW_DS101834
Teitl Amgen
Alternative Title
  • Gwyniad Hydroacoustic Survey 2003 - 2009 - CCW Science Report 903 - Countryside Coucil for Wales CCW000800000000C
  • Gwyniad Hydroacoustic and Gill netting survey of Llyn Arenig Fawr 2009 - CCW Science Report 904 CCW000800000000D
  • Llyn Arenig Fawr Hydroacoustic Gwyniad Surveys
  • Arolygon Hydroacwstig a Thrawsleoli Gwyniaid Llyn Tegid 2004 - 2009
Laith Metadata
Metadata Language
English
Lineage

Hydroacoustic surveys and measurements of environmental variables- temperature, oxygen profiles and secchi disk readings- have been carried out annually since 2004. (No secchi disk readings for 2008 survey). In 2005 an analysis of historic lake data in the context of gwyniad spawning requirements was also undertaken. The methodology technique used standardised survey and monitoring protocol for the assessment of whitefish (Bean, 2003, JNCC, 2005) with two minor deviations- rather than using the target strength to fish length relationship of Foote (1987) the relationship given by Love (1971) was used to allow wider comparison. Secondly a vessel speed of 2.0ms-1 was adopted as general target mean speed rather then an absolute upper limit. Translocation attempts involved seine netting conducted after dark, stripping was performed on the morning after sampling and the volume of eggs was determined. Viable gwyniad were returned alive to the lake. Eggs were transported to Llyn Arenig Fawr and introduced to incubation boxes. Fish population survey at the latter site was undertaken using hydroacoustics and gill netting.
Additional Information

Rivers Ecologist, Marine and Freshwater Science Group, NRW Data collected under project number FC 73-02-304. The species records which form part of this dataset are available to download from the NBN Gateway as part of a larger packaged species dataset.
Dyddiad cyfeirnod y set ddata (Cyhoeddiad)
Dataset Reference Date (Publication)
2009-12-31
Perchennog
Owner
  Natural Resources Wales (NRW)
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
Cychwynnwr
Originator
  Centre for Ecology and Hydrology (CEH)
Environment Centre Wales, Deiniol Road, Bangor, Gwynedd, LL57 2UW, Wales
http://www.ceh.ac.uk/
 

Extent

Extent

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


 
 

Distribution

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

    Specification

    Data is Archived under Project Number: 29, 154, 194 ,226, 227, 200 Media Numbers 169, 468, 539, 595, 232, 952 [A] Visual acquisition raw data derived from the echo sounder (*.dt4 format). [B] Echoview Data from the laboratory examination and analysis of output from the echo sounder and GPS used in the field (*.csv format). [C] Oxygen and temperature profiles [D] Secchi depth [E] Report: Report: CCW Contract Science Reports 903 and 904 in (PDF and Microsoft Word formats) [F] Translocation data includes max/min lake levels, max/min surface water temp, number of fish, egg volume, pictures and video clips. [G] 2004 survey includes- Hydroacoustic transect lengths, back calculations of lengths of under yearling gwyniad from a 2003 study [E] 2005 survey includes- Lake levels data (.csv format) [F] Species Data is also stored in Recorder 6: - CCW000800000000D Gwyniad Hydroacoustic and Gill netting survey of Llyn Arenig Fawr 2009 - CCW Science Report 904 - CCW000800000000C Gwyniad Hydroacoustic Survey 2003 - 2009 - CCW Science Report 903 - Countryside Coucil for Wales

 

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

Hydroacoustic surveys and measurements of environmental variables- temperature, oxygen profiles and secchi disk readings- have been carried out annually since 2004. (No secchi disk readings for 2008 survey). In 2005 an analysis of historic lake data in the context of gwyniad spawning requirements was also undertaken. The methodology technique used standardised survey and monitoring protocol for the assessment of whitefish (Bean, 2003, JNCC, 2005) with two minor deviations- rather than using the target strength to fish length relationship of Foote (1987) the relationship given by Love (1971) was used to allow wider comparison. Secondly a vessel speed of 2.0ms-1 was adopted as general target mean speed rather then an absolute upper limit. Translocation attempts involved seine netting conducted after dark, stripping was performed on the morning after sampling and the volume of eggs was determined. Viable gwyniad were returned alive to the lake. Eggs were transported to Llyn Arenig Fawr and introduced to incubation boxes. Fish population survey at the latter site was undertaken using hydroacoustics and gill netting.
 

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
  • Llyn Tegid
  • gwyniad (freshwater whitefish)
  • coregonus lavaretus
  • hydroacoustic
  • marine and freshwater inventory
  • secchi depth
  • oxygen profile
  • temperature profile
  • Llyn Arenig Fawr
Math
Type
Theme
Theme

Dyfyniad
Citation

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

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

Gwyniad translocation project 2004 - 05 : hydroacoustic survey of Llyn Tegid
NRW Related Title

Llyn Tegid hydroacoustic surveys 2005
NRW Related Title

Llyn Tegid hydroacoustic surveys 2006
NRW Related Title

Llyn Tegid hydroacoustic surveys 2007
NRW Related Title

Llyn Tegid hydroacoustic survey 2008
NRW Related Title

Gwyniad translocation project 2004-05 : translocation attempt
NRW Related Title

Llyn Tegid gwyniad translocation advice 2005-2006
NRW Related Title

Llyn Tegid gwyniad translocation advice 2006-2007
 

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 to 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 2008 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.
 
 
 

Metadata

Metadata

Dynodydd Ffeil
File Identifier
4f4c4942-4343-5764-6473-313031383334 XML
Laith Metadata
Metadata Language
English
Parent Identifier
Freshwater Gwyniad (Coregonus lavaretus) Species Survey Data

NRW_DS116344
Math o adnodd
Resource type
Dataset
Dataset
Dyddiad Metadata
Metadata Date
2024-05-31T09:40:23.833Z
Enw Safonol Metadata
Metadata Standard Name
NRW
Fersiwn Metadata
Metadata Standard Version

1.0

Pwynt Cyswllt
pointOfContact
  Master Reference Data Team
Natural Resources Wales, Maes y Fynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW
http://naturalresourceswales.gov.uk/splash?orig=/
 
 

Publishing Body

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