The abundance of large, piscivorous Ferox Trout ( Salmo trutta ) in Loch Rannoch, Scotland

PeerJ

article

Alastair Thorne¹  Alisdair I. MacDonald¹  Joseph L. Thorley² 

[1] Freshwater Laboratory;Poisson Consulting

关键词: Survival;    Hierarchical;    Bayesian;    Exploitation;    Jolly-Seber;    Abundance;    Ferox Trout;    Brown Trout;    Piscivorous;   

DOI  :  10.7717/peerj.2646

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

BackgroundFerox Trout are large, long-lived piscivorous Brown Trout (Salmo trutta). Due to their exceptionally large size, Ferox Trout are highly sought after by anglers while their life-history strategy, which includes delayed maturation, multiphasic growth and extended longevity, is of interest to ecological and evolutionary modelers. However, despite their recreational and theoretical importance, little is known about the typical abundance of Ferox Trout.MethodsTo rectify this situation a 16 year angling-based mark-recapture study was conducted on Loch Rannoch, which at 19 km2 is one of the largest lakes in the United Kingdom.ResultsA hierarchical Bayesian Jolly-Seber analysis of the data suggest that if individual differences in catchability are negligible the population of Ferox Trout in Loch Rannoch in 2009 was approximately 71 fish. The results also suggest that a single, often unaccompanied, highly-experienced angler was able to catch roughly 8% of the available fish on an annual basis.DiscussionIt is recommended that anglers adopt a precautionary approach and release all trout with a fork length ≥400 mm caught by trolling in Loch Rannoch. There is an urgent need to assess the status of Ferox Trout in other lakes.

【 授权许可】

CC BY