Llyn Tegid Hydroacoustic Surveys and Gwyniad Translocations 2004-2009

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.

Identifier: NRW_DS101834

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

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.

Dataset Reference Date (Publication): 2009-12-31

Temporal Extent

Begin date: 2004-08-05

End date: 2009-07-31

Topic category

Biota

Owner

Natural Resources Wales (NRW)

Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales

http://naturalresources.wales/?lang=en

Originator

Centre for Ecology and Hydrology (CEH)

Environment Centre Wales, Deiniol Road, Bangor, Gwynedd, LL57 2UW, Wales

http://www.ceh.ac.uk/

Extent

Geographic Extent: Wales (WLS)

Geographic Extent: GWYNEDD - GWYNEDD

Map representing the geographic extent of the dataset

Format Type and Description

Database 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

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
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

GEMET - INSPIRE themes, version 1.0

Species distribution

Type: Theme

Citation

Date (Publication): 2008-06-01

Code: geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme

Keywords

NRW Thesaurus

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

Type: Theme

Citation

Date (Publication): 2023-12-31

Code: geonetwork.thesaurus.local.theme.converted_nrw-keywords

Code: British National Grid (EPSG::27700)

Content Information

NRW Profile

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

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 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

File Identifier: 4f4c4942-4343-5764-6473-313031383334 XML

Metadata Language: English

Parent Identifier: Freshwater Gwyniad (Coregonus lavaretus) Species Survey Data
NRW_DS116344

Resource type: Dataset

Metadata Date: 2024-05-31T09:40:23.833Z

Metadata Standard Name: NRW

Metadata Standard Version: 1.0

pointOfContact

Master Reference Data Team

Natural Resources Wales, Maes y Fynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW

http://naturalresourceswales.gov.uk/splash?orig=/

Publishing Body

Access the portal

Full access to the portal and metadata.

Llyn Tegid Hydroacoustic Surveys and Gwyniad Translocations 2004-2009

Identification

Temporal Extent

Extent

Extent

Distribution

Quality

Data quality

Keywords

Keywords

Citation

Keywords

Citation

Spatial Reference System

Content

Content Information

NRW Profile

Custom Elements

Constraints

Constraints

Limitations on Public Access and Use

Access Constraints Directive

Access Constraints Text

Use Constraints

Metadata

Metadata

Publishing Body