Issue |
Aquat. Living Resour.
Volume 30, 2017
|
|
---|---|---|
Article Number | 11 | |
Number of page(s) | 7 | |
DOI | https://doi.org/10.1051/alr/2017011 | |
Published online | 29 March 2017 |
Research Article
Do otters target the same fish species and sizes as anglers? A case study from a lowland trout stream (Czech Republic)
Institute for Environmental Studies, Faculty of Science, Charles University in Prague,
Benátská 2,
12801
Prague, Czech Republic
⁎ Corresponding author: roman.lyach@natur.cuni.cz
Received:
14
September
2016
Accepted:
7
March
2017
Stocking of hatchery-reared fish into streams is a common practice in fisheries industry as it provides catches for recreational anglers and support for native fish populations. The Eurasian otter Lutra lutra is one of the most important freshwater piscivorous predators in Europe. Impact of otters on stocked fish is a source of conflict between fisheries industry and environmental protection. This study aimed to describe differences between otter diet and catches of anglers on a lowland trout stream with salmonid stocking. Otter diet was studied during winter, using spraint analysis. Fish dominated otter diet (85% of biomass). Gudgeon Gobio gobio was the most important otter prey (38% of biomass). Catches of otters and catches of anglers on the stream were significantly different. Otters mostly preyed upon small-growing fish species of medium or no angling value while anglers took large-growing fish species of medium and high angling value. Otters took fish with average weight of 10 g while anglers took fish with average weight of 290 g. Stocked salmonids made up 13% of estimated biomass in otter diet. Otters targeted significantly different fish species of different sizes than anglers did.
Key words: Brown trout Salmo trutta m. fario / Fish losses / Fish predation / Hatchery-reared fish / Pharyngeal bones / Rainbow trout Oncorhynchus mykiss
© EDP Sciences 2017
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.