Shahraki Mojgan Zare, Keivany Yazdan, Dorche Eisa Ebrahimi, Blocksom Karen, Bruder Andreas, Flotemersch Joseph, Bănăduc Doru
Department of Natural Resources, Isfahan University of Technology, Isfahan 84156-83111, Iran.
U.S. Environmental Protection Agency, Office of Research and Development, Corvallis, OR 97333, USA.
Fishes. 2023 Oct 31;8(11):1-24. doi: 10.3390/fishes8110538.
We assessed the distribution of alien fishes in the Karun River Basin, Iran. Fish were collected from 39 sites during the November-December 2018 low-flow period. In total, 39 fish species from nine orders and 14 families were documented. Among these, 10 species were alien to the basin (986 individuals; 15.7%). Four species were the most abundant alien species and primarily in impounded, downstream reaches. Redundancy analysis (RDA) was conducted to identify the extent of changes in alien fish assemblages with environmental parameters. RDA1 and RDA2 accounted for 36.24% and 25.33% of the variation of alien species, respectively. Altitude, depth, electrical conductivity, water temperature, turbidity, dissolved oxygen, and river width were the most significant parameters affecting alien species distributions. We present a dual-pathway cause-and-effect hypothesis proposing that alien fish species presence causes declines in the ecological status of native fish communities. We then explore how human-induced aquatic ecosystem degradation creates opportunities for alien species to invade new ecosystems, further impacting native fish communities. Our study contributes insight into the cause and effect of the presence of alien fish species in the Karun River Basin and emphasizes the urgency of conservation measures to protect this critically endangered watershed.
我们评估了伊朗卡伦河流域外来鱼类的分布情况。在2018年11月至12月的枯水期，从39个地点采集了鱼类样本。总共记录了来自9目14科的39种鱼类。其中，有10种是该流域的外来物种（986个个体；占15.7%）。有4种是数量最多的外来物种，主要分布在蓄水的下游河段。进行了冗余分析（RDA）以确定外来鱼类群落随环境参数变化的程度。RDA1和RDA2分别解释了外来物种变异的36.24%和25.33%。海拔、深度、电导率、水温、浊度、溶解氧和河宽是影响外来物种分布的最重要参数。我们提出了一个双途径因果假设，即外来鱼类物种的存在导致本地鱼类群落生态状况下降。然后，我们探讨了人为导致的水生生态系统退化如何为外来物种入侵新生态系统创造机会，进而进一步影响本地鱼类群落。我们的研究有助于深入了解卡伦河流域外来鱼类物种存在的因果关系，并强调采取保护措施保护这个极度濒危流域的紧迫性。
