Long-term changes in the diet of pike (Esox lucius), the top aquatic predator in a changing Windermere
Winfield, Ian J.; Fletcher, Janice M.; James, J. Ben. 2012 Long-term changes in the diet of pike (Esox lucius), the top aquatic predator in a changing Windermere. Freshwater Biology, 57 (2). 373-383. 10.1111/j.1365-2427.2011.02607.xBefore downloading, please read NORA policies.
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1. Pike (Esox lucius) is a key and flexible piscivore in many fresh waters of the northern temperate zone, but no previous studies have provided a continuous long-term perspective on its diet in response to changing environmental conditions. Here, we describe its winter diet from 1976 to 2009 in the North and South Basins of the lake of Windermere, U.K., where climate change, eutrophication and species introductions have combined to induce fundamental changes in the fish community. 2. A total of 6637 adult pike (fork length 390 to 1090 mm) was examined and found to have consumed a total of 4436 fish prey of which 98% of individuals identifiable to species comprised native Arctic charr (Salvelinus alpinus), brown trout (Salmo trutta), perch (Perca fluviatilis) and pike and non-native roach (Rutilus rutilus). Over the 34-year study period, the dietary importance of the salmonids Arctic charr and brown trout decreased, while that of the percid perch, the esocid pike and particularly the cyprinid roach increased. These changes were particularly marked in the more eutrophicated South Basin of the lake. 3. The above chronological trends in species-specific contributions to the diet composition of pike had considerable overall impacts. In the 1970s, pike diet composition was dominated by Arctic charr and brown trout which together comprised 94% of the diet. In contrast, in the 2000s, these two species accounted for just 55% of the diet, with perch and roach now comprising 41%. 4. Recent changes observed in the Windermere fish community of a decrease in native salmonids and an increase in cyprinids are consistent with the generally expected effects of climate change in the northern temperature zone. Here, we have shown that they have led to corresponding changes in the diet composition of pike. In turn, this may have implications for lake’s food web structure through shortening food chain length from the primary producers to the top aquatic predator.
|Item Type:||Publication - Article|
|Digital Object Identifier (DOI):||10.1111/j.1365-2427.2011.02607.x|
|Programmes:||CEH Topics & Objectives 2009 - 2012 > EHFI
CEH Topics & Objectives 2009 - 2012 > Water > WA Topic 2 - Ecohydrological Processes > WA - 2.4 - Quantify the importance of food web structure and trophic interactions ...
|Additional Information. Not used in RCUK Gateway to Research.:||This document is the author’s final manuscript version of the journal article, incorporating any revisions agreed during the peer review process. Some differences between this and the publisher’s version remain. You are advised to consult the publisher’s version if you wish to cite from this article. The definitive version is available at http://onlinelibrary.wiley.com|
|Additional Keywords:||climate change, eutrophication, lake, predator diet, species introductions|
|NORA Subject Terms:||Ecology and Environment|
|Date made live:||20 Dec 2011 11:08|
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