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.
- Dull adnabod
- Rhychwant
- Dosbarthiad
- Ansawdd
- Allweddeiriau
- System Cyfeirio Gofodol
- Cynnwys
- Cyfyngiadau
- Cynnal a chadw
- Metadata
Dull adnabod
- Dynodydd
- NRW_DS101834
- Teitl Amgen
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- 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
- English
- Datganiad
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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.
- Gwybodaeth ychwanegol
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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)
- 2009-12-31
Rhychwant
Rhychwant
- Hyd
- Wales (WLS)
- Hyd
- GWYNEDD - GWYNEDD
))
Dosbarthiad
- Fformat - Math a Disgrifiad
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-
Database
()
- Math
-
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
-
Database
()
Ansawdd
Ansawdd Data
- Cwmpas Ansawdd
- Dataset
- Datganiad
-
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.
Allweddeiriau
Allweddair
- Math
- Theme
Dyfyniad
- Dyddiad (Cyhoeddiad)
- 2008-06-01
Allweddair
- NRW Thesaurus
-
- Llyn Tegid
- gwyniad (freshwater whitefish)
- coregonus lavaretus
- hydroacoustic
- marine and freshwater inventory
- secchi depth
- oxygen profile
- temperature profile
- Llyn Arenig Fawr
- Math
- Theme
Dyfyniad
- Dyddiad (Cyhoeddiad)
- 2023-12-31
System Cyfeirio Gofodol
Cynnwys
Gwybodaeth Cynnwys
Proffil CNC
Elfennau CNC
- Teitlau cysylltiedig CNC
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Gwyniad translocation project 2004 - 05 : hydroacoustic survey of Llyn Tegid
- Teitlau cysylltiedig CNC
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Llyn Tegid hydroacoustic surveys 2005
- Teitlau cysylltiedig CNC
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Llyn Tegid hydroacoustic surveys 2006
- Teitlau cysylltiedig CNC
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Llyn Tegid hydroacoustic surveys 2007
- Teitlau cysylltiedig CNC
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Llyn Tegid hydroacoustic survey 2008
- Teitlau cysylltiedig CNC
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Gwyniad translocation project 2004-05 : translocation attempt
- Teitlau cysylltiedig CNC
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Llyn Tegid gwyniad translocation advice 2005-2006
- Teitlau cysylltiedig CNC
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Llyn Tegid gwyniad translocation advice 2006-2007
Cyfyngiadau
Cyfyngiadau
Cyfyngiadau ar Fynediad a Defnydd Cyhoeddus
- Math o Gyfyngiad
- Other restrictions
Cyfarwyddeb Cyfyngiadau Mynediad
- Cyfyngiadau
- no limitations
Testun cyfyngiadau mynediad
- Cyfyngiadau eraill
-
There are no access restrictions to this data. NRW may release, publish or disseminate it freely.
Defnyddiwch gyfyngiadau
- Cyfyngiadau Defnyddio
- Other restrictions
- Cyfyngiadau eraill
-
© 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
- 4f4c4942-4343-5764-6473-313031383334 XML
- Laith Metadata
- English
- Dynodydd Rhiant
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Freshwater Gwyniad (Coregonus lavaretus) Species Survey Data
NRW_DS116344
- Math o adnodd
- Dataset
- Dyddiad Metadata
- 2024-05-31T09:40:23.833Z
- Enw Safonol Metadata
- NRW
- Fersiwn Metadata
-
1.0