文章基本信息

标题：The effects of dams on longitudinal variation in river food webs
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作者：Ivor Growns ; Bruce Chessman ; Simon Mitrovic 等
期刊名称：Journal of Freshwater Ecology
印刷版ISSN：0270-5060
电子版ISSN：2156-6941
出版年度：2014
卷号：29
期号：1
页码：69-83
DOI：10.1080/02705060.2013.832423
出版社：Taylor & Francis
摘要：We examined the effects of two dams on longitudinal variation of riverine food webs using stable isotope and gut contents analyses along four rivers in the Hunter Valley in eastern Australia. Longitudinal 15 N enrichment was observed in most invertebrate taxa and food sources but significant longitudinal variation was rare for 13 C, and composition of gut contents of invertebrate taxa did not vary significantly with longitudinal position. Most invertebrates and food sources were more 15 N-enriched at sites immediately downstream of the dams than expected from their upstream longitudinal position, a result not mirrored by gut contents and 13 C. Enrichment of 15 N downstream may be attributed to altered water quality as a result of impoundment but further research is necessary to elucidate whether physico-chemical riverine processes or trophic mechanisms are responsible. Our observations regarding the influence of dams on isotope ratios are contrary to the few existing studies, suggesting the small volumes relative to annual inflows of dams in the present study limit downstream impacts by maintaining aspects of flow variability.
关键词：river regulation; tail waters; dams; water resource management; aquatic macroinvertebrates; stable isotopes