Distribution and Expansion of Alien Fish Species in the Karun River Basin, Iran
Citation:
Zare Shahraki, M., Y. Kaivany, E. Ebrahimi Dorche, K. Blocksom, A. Bruder, J. Flotemersch, AND D. Bănăduc. Distribution and Expansion of Alien Fish Species in the Karun River Basin, Iran. Fishes. MDPI, Basel, Switzerland, 8(11):538, (2023). https://doi.org/10.3390/fishes8110538
Impact/Purpose:
This manuscript provides findings from a study that examined the presence of alien fish species in the Karun River Basin, Iran. It also examines the potential environmental drivers of alien speices. Monitoring of the presence and extent of alien species in the basin is key to gauging the success of management practices geared towards protecting native and endemic fish species in the basin.
Description:
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.
URLs/Downloads:
DOI: Distribution and Expansion of Alien Fish Species in the Karun River Basin, Iran