Paleoecological reconstruction of the abundance dynamics of pacific herring (Clupea pallasii) in Okhotsk sea in the Holocene – Late Pleistocene

The dynamics of the Pacific herring ( Clupea pallasii ) abundance was reconstructed using mathematical modeling based on Bayesian statistics The Sea of Okhotsk. The age of the time of the nearest common ancestor (TMRCA) for herring aggregations in the water area of this sea was estimated in the range of 28-29 thousand years. It was suggested that the signal of genetic diversity accumulated by herring up to the last glacial maximum was offset by a decrease in the number of herring caused by the last ice age, during which the level of the World Ocean dropped by more than 130 meters relative to the present level. To verify this assumption, published results on changes in the level of world waters over at least the last 120 thousand years have been used. A strong reliable correlation was found between changes in the effective abundance (Ne) of Pacific herring and changes in the area of the Sea of Okhotsk and the level of the World Ocean (r = 0,77-0,91; p <1×10 -6 ). Traces of the beginning of the decline in the number of herring in the Sea of Okhotsk have been found, at least in the 120-year time range from the present. The authors attribute these changes to the well-known evidence of a decline in the number of this species since the beginning of the twentieth century, when anthropogenic activity in the seas of the Far East increased (excessive fishing by the Japanese navy, the development of the territories of the USSR Far East and, as a result, increased fishing of fish resources). The paper demonstrates the possibility of conducting interdisciplinary paleoecological research using both genetic, climatic, hydrological, and historical data.