Fish invading deserts: non‐native species in arid Moroccan rivers

Abstract

Desert rivers are highly dynamic systems in which dry periods, frequently involving the cessation of superficial flow, alternate with violent flash floods. In spite of their territorial importance and high functional and biological diversity, desert rivers have received little attention in the scientific literature, especially in Northern Africa. This study investigated the distribution of non‐native fish, their relationship with river damming and their potential impacts on native biodiversity in the main river basins draining arid areas of Morocco (Oued Draa, Oued Ziz and Oued Ghir), based on field sampling covering 84 stream reaches. Thirteen fish species were recorded, eight of which are non‐native. Two species (stone moroko, Pseudorasbora parva, and bleak, Alburnus alburnus) had not been previously recorded in Morocco, while the native sandsmelt (Atherina boyeri) had not been cited as an invader. Pumpkinseed (Lepomis gibbosus) was the most widely distributed non‐native fish. Non‐native fish species were associated with reservoirs, colonizing the regulated downstream reaches. In contrast, unregulated upstream reaches tended to be free of non‐natives. The low abundance of native fish in reservoirs seems to be caused by the impacts of introduced fish species. Management options for environmental flow are limited, owing to reduced water availability. Non‐native fish management should thus focus on limiting the spread of species already introduced and avoiding new introductions, especially into reservoirs. Copyright © 2014 John Wiley & Sons, Ltd.

Freshwater conservation assessments in (semi-)arid regions: Testing river intermittence and buffer strategies using freshwater mussels (Bivalvia, Unionida) in Morocco

“…Gomes-dos-Santos, et al Biological Conservation 236 (2019) 420-434 et al, 2015. The haplotype from the endorheic Ziz basin is closer to Tunisian haplotypes than to Moroccan ones, suggesting gene-flow during past wet periods in the Sahara like during the mid-Holocene (Drake et al, 2011;Clavero et al, 2015). Even though the demographic history tests were inconclusive, when excluding Ziz haplotype the Fu's Fs results are significant for a recent expansion.…”

Pearl mussels (Margaritifera marocana) in Morocco: Conservation status of the rarest bivalve in African fresh waters

“…The presence of invasive species in Moroccan freshwater ecosystems have been increasing in recent years (Clavero et al, 2012(Clavero et al, , 2015. While the abundance of the Asian clam C. fluminea in the Oum Er Rbia river basin is not very high compared to other invaded systems, special attention should be given to this species considering the previously described ecological impacts on native unionoids (for a review see Sousa et al, 2008aSousa et al, , 2008bCrespo et al, 2015) and recognizing that at several sites M. marocana and C. fluminea co-exist.…”

A review of the Leon springs pupfish (Cyprinodon bovinus) long‐term conservation strategy and response to habitat restoration

“…In addition to concerns over habitat loss and reproductive ecology, groundwater pumping and drying of surface springs is a major challenge for maintaining small populations of desert fish (Armstrong and McMillion, ; Hubbs and Echelle, ; Williams et al, ; Leiser and Itzkowitz, ; Clavero et al, ). Both watercourses in Diamond Y Draw have been reported to be declining in length since the 1970s (Hubbs et al, ; Echelle and Echelle, ).…”