Variations in the Perilene Content in the Surface Layer of the Bottom Sediments of Lake Baikal

The article presents data on the content of perylene and other priority PAHs in the bottom sediments of the coastal part of Lake Baikal in 2024, obtained by HPLC with fluorimetric detection. The perylene concentrations in the Lake Baikal sediments ranged from 0.2 to 273.2 ng/g (dry weight). Minimum perylene concentrations were determined in inequigranular sands with low organic matter content. A higher average perylene content was found in the sediments at the BAM (77.9 ng/g, n = 18) and BPPM (72.6 ng/g, n = 30) testing sites compared to the Selenga area (25.7 ng/g, n = 13). At the BAM testing site in the northern part of Lake Baikal, the average perylene content exceeded by approximately 1.5 times the sum of priority PAHs (50.3 ng/g), by contrast to the BPPM and Selenga sites. Compared to the high correlation [Pearson correlation coefficient (PCC) > 0.75] between the sum of PAHs and organic carbon in the sediments of the surveyed sites, the relationship between perylene and organic carbon is weaker (PCC = 0.10–0.54). It was shown that high perylene concentrations can be present not only in deeper layers of bottom sediments but also in the surface layer, which can be associated with biogenic, rather than anthropogenic, origin of perylene.