Soil invertebrates and heavy metal concentrations are heterogeneously distributed in the soil of steppe plots surrounding an iron mining enterprise in southern Russia. This study assesses whether patches of high soil invertebrate abundance coincide with patches of low concentrations of pollutants. For this aim, spatial analysis by distance indices (SADIE) was applied. Three valleys in Belogorye Nature Reserve were chosen. One valley faced the tailing pond to the north and the other two faced south-east or south-west. Two sampling plots were chosen in each valley, 60 m apart from each other. On every plot 16 soil cores were collected from a grid of 4 × 4 units with a 5-m distance between each sample unit. Each soil core had an area of 76 cm 2 and was 12-15 cm deep. All macroinvertebrates were hand-sorted and identified to family. Abundance of soil invertebrates was not controlled by patches of metal concentration in the soil. Epigaeic groups, like insects and other invertebrates inhabiting the litter layer, were not directly associated with local parameters of the soil. On the contrary, belowground invertebrate abundance (elaterid larvae and earthworms) showed significant dissociation with some heavy metal (Fe, Pb, Zn) concentrations in the soil. The patchiness of soil pollution may act as a leading factor of belowground soil invertebrate distribution. The spatial structure of animal populations in industrially transformed soils needs further research.

In the White Sea the colonial hydroid Laomedea flexuosa inhabits a narrow belt of the lower littoral zone. How is so limited a habitat determined? We studied the time of planula release and the behaviour of larvae during the free-swimming stage and settlement in natural and laboratory conditions. Three methods were used to record the tidal-dependent dynamic of planula release: (1) plankton collecting bags around Fucus distichus macrophytes with mature hydroid colonies; (2) active stirring of Fucus with hydroids in a container with water, which is an old way to stimulate planula release; and (3) direct counts of the mature planulae in gonangia. The dynamic intensity of L. flexuosa planula release was investigated according to 3–4 phases of the tidal cycle. A moment of general release of larvae was shown to be correlated with a period of low water. Following the incoming tide keeps planulae in the littoral area. The planulae of L. flexuosa have a short period of swimming (less than 30 minutes), unlike those of Gonothyrae loveni and Dynamena pumila whose swimming period is about 36 hours. Quick settlement and tidal planula release could explain the strong spatial limitation in the distribution of L. flexuosa within the lower level of the intertidal zone. It is hypothesized that distribution over large areas is most likely by drift of colonies attached to detached seaweeds. Our outlook about the biological ways of ecological niche differentiation among marine organisms is broadened by the results of this study.

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Nowadays, after a long period of depression, Japanese sardine (Sardinops sagax) is on the rise. At a high stock level, this species expands its range, migrating to high-productivity Northwest Pacific Ocean areas, where it becomes available to Russian fishery. The article analyzes the long-term catches, as well as provides fishery catches data for 2021. The article also describes distribution and biological status of Japanese sardine during a scientific survey, carried out in the Pacific Ocean waters of the Southern Kuril Islands in October 2019. The article analyzes Japanese sardine nutrition in the feeding grounds.