Seasonal variability in the abundance of Arctic charr (Salvelinus alpinus (L.)) recorded using hydroacoustics in Windermere, UK and its implications for survey design
Winfield, I.J.; Fletcher, J.M.; James, J.B.. 2007 Seasonal variability in the abundance of Arctic charr (Salvelinus alpinus (L.)) recorded using hydroacoustics in Windermere, UK and its implications for survey design. Ecology of Freshwater Fish, 16 (1). 64-69. 10.1111/j.1600-0633.2006.00170.xFull text not available from this repository.
Hydroacoustic surveys are an important tool for assessing the abundance of Arctic charr (Salvelinus alpinus (L.)) in lakes, the requirement for which is increasing because of new environmental legislation. Consequently, survey demand is now such that assessments must be undertaken with the minimum of effort compatible with scientific validity. One major complication is seasonal variability in abundance, with which surveyors have attempted to deal by defining somewhat arbitrary seasonal sampling windows. The definition of more objective windows was pursued by analysing variations in the seasonal abundance of Arctic charr in Windermere, UK, recorded using day and night hydroacoustic surveys at monthly intervals from 1991 to 2001. Two alternative sampling windows for night surveys free of significant internal seasonal effects were revealed, i.e., December to September and September to December. It was also found that day surveys gave a useful, although lower, estimate of abundance as compared with night surveys.
|Programmes:||CEH Programmes pre-2009 publications > Water|
|Additional Keywords:||Arctic charr, hydroacoustics, echo sounding, seasonal variation, diel variation, survey design|
|NORA Subject Terms:||Ecology and Environment|
|Date made live:||12 Dec 2007 12:45|
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