Responses of Aquatic Organisms to Cyanobacteria and Elodea in Microcosms
The aim of the present study is investigation of the impact of mass development of cyanobacteria and Elodea on population characteristics (abundance, biomass, fecundity) and “health” parameters (the state of embryos, heart rate, and thermal resistance) of aquatic invertebrates in experiments with controlled conditions. In July–August 2018, in four variants of microcosms, the conditions were modeled characteristic of the coastal zone of the Rybinsk Reservoir in the period of mass development of cyanobacteria. Mass species were placed in microcosms of planktonic (with domination (80%) Daphnia longispina) and bottom animals (Unio pictorum, Gmelinoides fasciatus, Asellus aquaticus), as well as Elodea canadensis. In the variants with cyanobacteria, the toxic microcystins LR were revealed (24–53% of the sum of toxins, or from 6.6–66.5 μg/L). The presence of cyanobacteria (Aphanizomenon flos-aquae, Microcystis aeruginosa, and Gloeoitrichia spp.) influenced structural parameters of plankton: the quantity to green algae decreased, small-sized crustaceans increased. Influence of cyanobacteria caused reliable changes in parameters of aquatic animal from those of the control: thermal resitance of mollusks and amphipods decreased, time of restoration of heart rate after loads (salinity test) in mollusks increased; in amphipods, individual fecundity decreased, frequency of abnormalities and of mortality of embryos increased. The presence of Elodea intensified these effects. Thus, mass development of cyanobacteria and Elodea influences ecological–physiological parameters of aquatic animals, decreasing their adaptivity to natural stresses and deteriorating the quality of the progeny.
The study was supported by the Ministry of Education and Science of the Russian Federation (project nos. АААА-А18-118012690101-2, АААА-А18-118012690096-1, and АААА-А19-119020690091-0) and by the Russian Foundation of Basic Research (project no. 18-04-01069-a).
COMPLIANCE WITH ETHICAL STANDARDS
Conflict of interests. The authors declare that they have no conflict of interest.
Statement on the welfare of animals. All applicable international national, and/or institutional guidelines for the care and use of animals were followed.
- 1.Kolmakov, V.I., Sib. Ekol. Zh., 2014, vol. 21, no. 4, pp. 601–613.Google Scholar
- 5.Gagala, I. and Mankiewicz-Boczek, J., Pol. J. Environ. St., 2012, vol. 21, pp. 1125–1139.Google Scholar
- 7.Kravtsova, L.S., Izhboldina, L.A., Mekhanikova, I.V., Pomazkina, G.V., and Belykh, O.I., Zh. Biol. Inv., 2010, no. 2, pp. 2–16.Google Scholar
- 12.Gorokhova, E., Sundelin, B., and Berezina, N., HELCOM Technical Report, 2018. https://doi.org/10.13140/RG.2.2.34346.52162
- 14.Kurbatova, S.A., Ershov, I.Yu., and Borisovskaya, E.V., Biol. Vnutr. Vod, 2017, vol. 1, pp. 84–92.Google Scholar