Zoological Studies

Vol. 60, 2021

(update: 2021.03.15; 05.31)
 

Crustacean Fauna of the Aral Sea and its Relation to Ichthyofauna During the Modern Regression Crisis and Efforts at Restoration

Igor S. Plotnikov1, Nikolai V. Aladin1, Jens Mossin2, and Jens T. H°eg3,*

doi:10.6620/ZS.2021.60-25

1Zoological Institute, Russian Academy of Sciences, Universitetskaya nab. 1, St. Petersburg 199034, Russia. E-mail: Igor.Plotnikov@zin.ru (Plotnikov); Nikolai.Aladin@zin.ru (Aladin)
E-mail: lingdorishuamanivalderrama@gmail.com (HuamanÝ-Valderrama); elopezt@unsa.edu.pe (Lˇpez-Tejeda); alazor@unsa.edu.pe (Lazo-Rivera)
2Gentoftegade 76, DK-2820 Gentofte, Denmark. E-mail: jmobranc@gmail.com (Mossin)
3Section of Marine Biology, Department of Biology, University of Copenhagen, Universitetsparken 4DK-2100 Copenhagen, Denmark. *Correspondence: E-mail: jthoeg@bio.ku.dk (H°eg). Phone: +45 28 75 12 47

Received 31 October 2020 / Accepted 17 February 2021
Communicated by Benny K.K. Chan

The regression and salinization of the Aral Sea, largely caused by water diversion for irrigation, is among the most severe ecological disasters of the 20th century, and has had severe health and economic consequences for the local population. Introductions of alien species to enhance commercial fisheries before the regression had already impacted the ecology of this system. Crustaceans made up about one-quarter of the original metazoan species and constituted the principal food for native and introduced fish. From 1960 on, crustaceans were recorded at numerous fixed sampling stations, including thanatocoenoses (dead animals from sediment cores). We use this previously unpublished information to document changes in species abundance and discuss their causes in the context of species interactions and changes to physical and chemical parameters. Competition from alien crustaceans led to declines in or even extinction of some native species, but eventually severe salinization became the main detriment, and resulted in the complete collapse of commercial fisheries. This seriously hurt a critical trade, which provided the principal protein source for the local population. We document how comparatively modest conservation efforts enabled the northern Small Aral Sea to partially recover and commercial fishing to resume.

Key words: Conservation, Fisheries, Long term monitoring, Saline lake, Introduced species.

Citation: Plotnikov IS, Aladin NV, Mossin J, H°eg JT. 2021. Crustacean fauna of the Aral Sea and its relation to ichthyofauna during the modern regression crisis and efforts at restoration. Zool Stud 60:25. doi:10.6620/ZS.2021.60-25.