Light pollution can affect various groups of aquatic organisms. This effect will vary depending on the color temperature of the artificial lighting. However, at the moment, the issue of adaptation of organisms to light pollution and the influence of different color temperatures on them has not been well-studied. In this study, we decided to conduct a series of experiments with individuals of the amphipod Gmelinoides fasciatus from two populations and find out how individuals adapted to light pollution. The first group of individuals is from the population in Lake Baikal (Bolshie Koty Bay), and the second group is from the population in the Angara River (within the city of Irkutsk). The second population is significantly affected by light pollution. Since the middle of the last century, there has been an artificial barrier between these populations in the form of a hydroelectric power station. The experiments showed that G. fasciatus individuals developed different behavioral strategies in relation to artificial lighting with different color temperatures. In warm light, individuals tend to move to a shaded area, while in cold light, individuals may be attracted to artificial lighting, but only in small groups. These identified patterns may likely find practical use.

Light pollution can have a variety of effects on aquatic organisms. Despite the fact that amphipods are one of the model organisms for studying the effects of light among macroinvertebrates, data on the reaction of Baikal amphipods to artificial lighting are limited and contradictory. In this study, we examine the response of Baikal littoral and sublittoral amphipod species to artificial lighting of varying intensity and spectral composition. In the experiments, amphipods were exposed to warm and white light at three different intensity ranges (5–15, 20–35, and 80–100 lx), as well as blue and red light. As a result, it was found that the reaction of Baikal amphipods to different lighting conditions was species-specific and dependent on the spectral composition of the light more so than the intensity of the light. In particular, white LED light generally repulsed E. cyaneus, but tended to attract A. godlevskii. P. cancelloides, and G. fasciatus, suggesting that white LED light may have a greater negative impact on wildlife than warm LED light. Generally, artificial light influences the behavior of Baikal amphipods, and an increase in light pollution on Lake Baikal may lead to changes in the littoral community in certain areas of the lake subject to pollution.

Most studies on microplastic pollution in aquatic ecosystems have focused on the quantitative and qualitative assessment of particles in surface waters. However, the highest concentrations and accumulation of microplastic particles are observed in bottom sediments. The aim of this study was to determine the concentrations of microplastic particles of different morphology in sediments in the beach and littoral zones of Lake Baikal. This study is the first in relation to Lake Baikal to focus specifically on the analysis of microplastic particles in bottom sediments. The results of the study showed that the registered values of concentration of microplastic particles do not exceed the average values for lakes around the world. The predominant type of particles in both the littoral zone and the beach is microplastic fibers. An exception is observed only for one of the locations. This exception is related to the permanent mooring of vessels in this place. Analysis of the types of artificial polymers showed that the microplastic fibers were represented by polyester, and the fragments were represented by alkyd resin (66%), polyvinyl alcohol (32%) and polyvinyl chloride (2%). Shown for the first time in this study, the presence of large numbers of microplastic particles with rare types of artificial polymers suggests that these particles may be under-reported in other studies. The underestimation of particles may be due either to the selection of sampling locations located far from heavily contaminated areas, or to the fragility of these polymers. Although the harm of these types of polymers has not yet been confirmed, the large number of these particles in local areas of lakes should be taken into account. This is due to the large number of organisms, which is usually characteristic of littoral areas, including Lake Baikal, with its diversity of fauna and flora.

In this study, we present a list of crustaceans traced in plankton of the southern basin Lake Baikal in addition to some details regarding ecological peculiarities of the only known freshwater pelagic amphipod Macrohectopus branickii. The amphipod is an active predator among major parts of the Lake Baikal food chain. Its role in the lake’s ecosystem is similar to that of Antarctic krill and mysids in Europe and North America water bodies. As an active swimmer, M. branickii performs daily vertical migrations. Besides, the species also has horizontal migrations and migrating swarms, including time during breeding period, that hamper species studies. We were interested in clarify some features of the species ecology. As a material we used samples obtained in the 0 to 250 m water layer with a plankton Juday net every 7 to 10 days from 2013 until 2018 as a part of long-term ecological monitoring project of Lake Baikal pelagial. Sampling was conducted in the southern part of the lake off the shore of Bolshie Koty Village. The results showed the presence of one peak of young during breeding period, which is at its maximum in May. The maximum of the 1 to 6 mm group containing young individuals and males occurs in July, and during the same period, a slight increase in immature females in comparison with the first group can also be seen. This finding might be directly linked to the warming trend in Lake Baikal.

Macrohectopus branickii является уникальным обитателем пелагиали оз. Байкал, схожим по экологической нише с антарктическим крилем и мизидами. Несмотря на это многие аспекты экологии данного вида являются неизвестными, либо спорными. В рамках данной работы предполагалось уточнить особенности распространения данного вида в прибрежной зоне. Поскольку особи M. branickii являются активными мигрантами и участвуют в суточных вертикальных миграциях к поверхности, нами были использованы конусные сети, рассчитанные на то, что M. branickii будет попадать в них при совершении пассивного опускания от поверхности льда в толщу воды. Полученные данные показали присутствие особей M. branickii над глубиной в 47 м, а также то, что мигрирующие стаи представителей данного вида могут долгое время не заходить на определенные участки. Также в работе были рассмотрены вопросы явления вмерзания M. branickii в ледовый покров и его значение в экологии данного вида.

Microplastic pollution of ecosystems is considered a modern problem. Freshwater ecosystems, despite the interest shown in their study, remain poorly understood. Lake Baikal (Russia) is one of the least studied freshwater ecosystems in this regard. This large lake is distinguished from others by its high level of biodiversity and clean drinking water. The aim of this study is a multi-matrix investigation of microplastic pollution in one of the lake’s bay. The following matrices are used: surface water, water column, sediment, macrophytes, macroinvertebrates, and fish, as well as ice and snow during the winter. The results show that certain locations exhibit high concentrations of microplastic particles. In some cases, this was due to the properties or characteristics of these locations (littoral zones near the water’s edge, macrophytes with mucus sheaths, ice and snow (potentially, the near-surface water layer after ice melt)), while in others, it was due to localized pollution (pier and ship mooring areas). An analysis of the polymer types of the detected microplastic particles reveals the presence of both common (polypropylene, polyethylene terephthalate, polystyrene, polyethylene, polyvinyl chloride) and rare (polyvinyl alcohol and alkyd resin). Moreover, in some locations, the latter two polymers predominate, a phenomenon rarely observed in other studies. Further research was recommended to focus on the chronic effects of microplastic particles on organisms associated with areas of elevated particle concentrations.