When a river is affected by a reservoir: Trophic interactions and flexibility in feeding strategies of alpine bullhead (Cottus poecilopus) and European bullhead (Cottus gobio)

STEVOVE, Barbora, Miroslava BABELOVA, Danka HARUŠTIAKOVÁ and Vladimir KOVAC. When a river is affected by a reservoir: Trophic interactions and flexibility in feeding strategies of alpine bullhead (Cottus poecilopus) and European bullhead (Cottus gobio). Science of the Total Environment. Amsterdam: Elsevier Science, 2019, vol. 651, February, p. 1903-1912. ISSN 0048-9697. Available from: https://dx.doi.org/10.1016/j.scitotenv.2018.10.068.

Basic information

• Original name: When a river is affected by a reservoir: Trophic interactions and flexibility in feeding strategies of alpine bullhead (Cottus poecilopus) and European bullhead (Cottus gobio)
• Authors: STEVOVE, Barbora (703 Slovakia), Miroslava BABELOVA (703 Slovakia), Danka HARUŠTIAKOVÁ (703 Slovakia, guarantor, belonging to the institution) and Vladimir KOVAC (703 Slovakia).
• Edition: Science of the Total Environment, Amsterdam, Elsevier Science, 2019, 0048-9697.

Other information

• Original language: English
• Type of outcome: Article in a journal
• Field of Study: 10511 Environmental sciences
• Country of publisher: Netherlands
• Confidentiality degree: is not subject to a state or trade secret
• WWW: Full Text
• Impact factor: Impact factor: 6.551
• RIV identification code: RIV/00216224:14310/19:00108987
• Organization unit: Faculty of Science
• Doi: http://dx.doi.org/10.1016/j.scitotenv.2018.10.068
• UT WoS: 000450551600025
• Keywords in English: Montane river; Anthropogenic disturbance; Fish; Competition for food; Altitudinal distribution
• Tags: 14119612, podil, rivok
• Tags: International impact, Reviewed

Abstract

The alpine bullhead and European bullhead are benthic fish species protected by law in several European countries. One of the problems of European rivers is the ever-increasing number of reservoirs, which has adverse impacts on aquatic ecosystems. Feeding ecology of both species evaluated separately has been a subject of several studies, however, none of the studies paid attention to feeding interactions between them. Thus, the aims of the study were to evaluate trophic interactions of the two bullhead species and to assess their ability to cope with environmental disturbances caused by a reservoir. The study area consisted of three sites on the river Cierny Vah (Slovakia) that differed from each other by the intensity of pressures posed by the reservoir. The two species were found to coexist at two sites below the reservoir, because the reservoir affected their distribution along the river. For alpine bullhead, chironomid, hydropsychid and baetid larvae were the most important prey items, whereas the diet spectrum of European bullhead contained hydropsychid, chironomid larvae and detritus. Differences in diet composition were found among sampling sites. Temporal variations in the diet composition demonstrated that alpine bullhead is a more flexible feeder than European bullhead. Being predominantly food generalists, both species were able to shift their feeding strategies towards specialization when exposed to environmental disturbances at the most affected site. The reservoir increased the diet overlap between the two species, and thus changed their trophic interactions. Both alpine bullhead and European bullhead managed to cope with environmental disturbances caused by the reservoir, however, in lower population densities. Moreover, the reduced diversity of resources increased the potential for trophic competition between them.