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Bean, C.W. (2003a). A standardised survey and monitoring protocol for the assessment of Arctic charr, Salvelinus alpinus L., populations in the UK. Joint Nature Conservation Committee, Peterborough 41pp.

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Bean, C.W. (2003a). A standardised survey and monitoring protocol for the assessment of Arctic charr, Salvelinus alpinus L., populations in the UK. Joint Nature Conservation Committee, Peterborough 41pp.
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  A standardised survey and monitoring protocol for theassessment of Arctic charr, Salvelinus alpinus L ., populationsin the UK FINAL REPORTPrepared by:Dr Colin BeanScottish Natural HeritageAdvisory ServicesFreshwater Group January 2003  2 CONTENTSPageExecutive Summary41. Introduction6The Biology of Arctic charr within the UK72. Arctic Charr Distribution7 2.1 Global Distribution72.2 Distribution Within the British Isles9 3. Biology of the Arctic Charr11 3.1 The ‘Arctic Charr Complex’113.2 Age and Growth133.3 Spawning and Fecundity153.4 Diet and Feeding163.5 Parasites and Disease17 4. Conservation Status175. Exploitation of Natural Stocks18Sampling and Monitoring of Arctic Charr Populations196. Review of Arctic charr sampling methodologies 197. Description of selected sampling methods20 7.1 Gill netting207.2 Hydroacoustics22 8. Sampling strategy24 8.1 Spatial distribution of gill nets248.2 Temporal considerations258.2.1 Diel258.2.2Seasonal258.3 Hydroacoustic survey design268.3.1 Timing 268.3.2 Survey Coverage 26 9. Laboratory treatment of Arctic charr samples 27 9.1 Storage279.2 Somatic measurements289.3 Assessment of maturity and age289.4 Condition28 10. Estimation of Arctic charr density29  3 11. Reporting2912. Assessment of Conservation Status3013. Costings3214. Acknowledgements3215. References33  4 EXECUTIVE SUMMARYBackground One of the special functions of the three country agencies (Scottish NaturalHeritage, Countryside Council for Wales, and English Nature) is theestablishment of common standards throughout Great Britain for themonitoring of nature conservation. The standards will apply to statutory sitesdesignated as Sites of Special Scientific Interest (SSSIs) and Areas of SpecialScientific Interest (ASSIs). They will also apply to areas designated as part of the Natura 2000 series, (Special Areas of Conservation (SACs) and SpecialProtection Areas (SPAs) under the EU Habitats Directive (92/43/EEC) and EUBirds Directive (79/409/EEC), together with Ramsar sites designated under the Convention on Wetlands of International Importance. A review of ecological and habitat needs of Arctic charr suggests that water quality and the availability of suitable spawning areas are the key featureswhich dictate their distribution and abundance. Arctic charr condition assessment Three strategies are proposed for assessment of conservation status of Arcticcharr populations in SSSIs.  Abundance classification : The first approach classifies the density of Arcticcharr in order to establish the relative condition of fish populations in lakes.Relatively few comparative data are available for this species to enablecomparisons to be made within individual SSSIs or with other waters.Using the only Arctic charr density estimates available for  oligotrophic systems, it appears reasonable to conclude sites which contain Arctic charr asa notified interest and have fish density estimates which fall below a levelof 37 individuals/ha -1 are considered to be in unfavourable condition .Similarly, for  mesotrophic waters, it may be useful in the first instance, toconsider a density estimate of  520 individuals/ha -1 to act as a threshold for favourable condition . Population demographic structure:  A further assessment can be made of the demographic structure of the population, i.e. the contribution of differentage classes to the population to demonstrate recruitment success. It issuggested that to achieve favourable condition Arctic charr populationsshould have 70 % of individuals in the 0+/1+ age class. Hydroacoustic survey data will provide data relating to the size andabundance of larger fish size classes. It is essential that information obtainedby hydroacoustic methods is supported by ageing data obtained from theotoliths of captured fish.  5   Maintenance of habitat quality:  Arctic charr are sensitive to changes inwater quality and habitat. Lacustrine water and habitat quality should notdeteriorate. Changes in habitat quality through nutrient enrichment,siltation, gravel exposure or loss of spawning substrate should not haveoccurred to any degree if favourable condition is to be recorded.Monitoring strategy Monitoring by a combination of targeted NORDIC style multi-mesh gill nettingand quantitative hydroacoustics is recommended as the approach to providean overview of the status of the Arctic charr populations within SSSI’s. Allsampling should be carried out over crepuscular and nocturnal periodsbetween the months of July and August.Other data required to interpret the status of Arctic charr populations includefork length, weight, condition, sex and state of maturity. Both scale samplesand otoliths should be removed from each fish, although otolith reading isrecommended as the primary method for Arctic charr.Information relating to the nutrient status of each waterbody containing Arcticcharr is also required. If possible, this information should be viewed againstlong-term data sets.Prior to undertaking fisheries surveys there is a need to ensure theappropriate access permission and fishing rights have been obtained. Costings  Approximate costings for carrying out a monitoring survey for Arctic charr byexternal consultants are provided.
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