Affiliation:
1. Department of Science and Technology Graduate School of Medicine, Science and Technology, Shinshu University Nagano Japan
2. Sugadaira Research Station, Mountain Science Center, University of Tsukuba Nagano Japan
3. Nagano Environmental Conservation Research Institute Nagano Japan
4. Nikko Field Station, Fisheries Technology Institute, Japan Fisheries Research and Education Agency Tochigi Japan
Abstract
AbstractSalmonids have been introduced globally as a food source and recreational fishing target. In Japan, brown trout (Salmo trutta) and brook trout (Salvelinus fontinalis) were introduced in the 19th century and have since spread. In many headwater streams, native white‐spotted charr (Salvelinus leucomaenis) are thought to be experiencing negative impacts from these species. The current study examined foraging behavior, microhabitat use, and diet overlap of these three species in Kamikochi, Nagano Prefecture: one of Japan's premier mountain areas. In Kamikochi, many spring‐fed headwater streams are currently dominated by these invasive salmonids and white‐spotted charr have declined drastically over the last half century. Underwater video analysis revealed that while total foraging rates and foraging modes were similar between the three species, brook trout and white‐spotted charr foraged benthically more frequently than brown trout. Microhabitat water depth and flow velocity were similar between species, and fish size had a positive effect on water depth and flow velocity in all three species. Diet analysis indicated that brook trout and white‐spotted charr diets were nearly identical, comprised primary of aquatic invertebrates, while brown trout preyed on a mix of terrestrial and aquatic invertebrates, as well as amphibians and fish. These results indicate that in Kamikochi, the decline of white‐spotted charr is likely most influenced by direct competition with brook trout for prey resources. However, brown trout likely also predate on juvenile white‐spotted charr, while also possibly causing a foraging niche shift of white‐spotted charr, and have ecosystem‐level impacts due to predation on terrestrial prey.
Funder
Japan Society for the Promotion of Science
Subject
Ecology, Evolution, Behavior and Systematics
Reference59 articles.
1. Impacts of Nonnative Brown Trout on Yellowstone Cutthroat Trout in a Tributary Stream
2. Predicting the outcomes of management strategies for controlling invasive river fishes using individual‐based models
3. Azumi Village. (1998).Nature: Chapter 8 animals.Azumi Village Magazine 1: (1998.3.30).
4. Quantifying Stream Substrate for Habitat Analysis Studies
5. Feeding ecology of various length‐classes of brown trout (Salmo trutta) in different streams of Coruh River, Turkey;Becer‐Ozvarol Z. A.;Kafkas Universitesi Veteriner Fakultesi Dergisi,2011
Cited by
2 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献