Global warming, which certainly covered the Black Sea, caused serious structural and functional changes in the pelagic community, effecting marine bioluminescence, which is an expressive indicator of the environment state. A large number of intensely luminescent warm-water ctenophores-invaders appeared in the surface layer, which increased the total plankton luminescence. Their contribution to the total luminosity of the coastal waters has been poorly studied so far. In practical terms, it resulted in changing of unmasking luminosity of any moving objects in the water column. On the other hand, developing of more sensitive methods for monitoring changes in the marine environment state has become possible.
<p>Our study examines the features of photosynthetic processes that occurred in the coastal area of the south-eastern Baltic Sea during the advanced phase of intensive summer bloom of 2018. We aim for a better understanding of short-time variability in primary production coupled with planktonic composition and phytoplankton functional activity in relation to location of nutrients sources on the coast and sub-mesoscale eddies, which appear over the coastal slope of Cape Taran and move alongside the Sambia Peninsula coast. These two-day studies, conducted on board of research vessels, represent a snapshot of a highly variable ecosystem alongside the Sambia Peninsula and Curonian Spit at the end of summer. Satellite images of sea surface temperatures and chlorophyll &#171;a&#187; concentration were also used for identification of spatial variations and eddies; the circulation conditions were derived from the operational system SatBaltyk. Across the coastal area, the effects of physico-chemical conditions influenced the phytoplankton composition and photosynthetic activity. In the south, the hot weather as well as the impacts of the Vistula Lagoon and the Amber combine affected the increase of nutrients and caused the strongest cyanobacterial bloom. In the Cape Taran area, the plankton community was transformed as a result of sub-mesoscale eddies development. Substantial gradients of nutrients, composition, biomasses and functional activity of phytoplankton along transects through eddies field was shown.</p><p>Collecting of samples was done with a support of the state assignment of Shirshov Institute of Oceanology, Russian Academy of Sciences (topic no. 0149-2019-0013). Data processing was supported by the state assignment of Shirshov Institute of Oceanology, Russian Academy of Sciences (topic no. 0149-2019-0006) and RFBR grant ( no.19-05-50090).</p>
The toxic impact of a mixture of polychlorinated biphenyls Aroclor 1254 (PCB) on the luminescence characteristics of the ctenophores Mnemiopsisleidyi A. Agassiz was studied. The control group was kept in an aquarium without a toxicant; experimental individuals were placed in three aquariums with water with PCB concentrations of 1, 10, and 100 µg -1 with an exposure of 15, 30, 40 and 60 minutes. Bioluminescence of M. leidyi was studied using the “Svet” complex. The toxic impact of PCBs caused a decreased amplitude and duration of luminescence at all given concentrations, whereas one-hour exposure to mechanical agitation resulted in a maximum decrease by 35% in the glow duration. At a PCB concentration of 1 μg ∙ L -1 , a maximum decrease in the luminescence intensity by a factor of 20 was observed compared with the control group.
В летний период 2018 г., в районе от мыса Тарханкут до Кавказского побережья Черного моря была выполнена съемка полей биолюминесценции, температуры, электропроводности и фотосинтетически активной радиации. Исследования проводили на стандартной мониторинговой сетке станций, на которых осуществляли зондирования биофизическим комплексом «Сальпа-М» с синхронным отбором проб фитопланктона. Было установлено, что с началом летнего прогрева вод в исследуемом районе интенсифицируется развитие одноклеточного планктона, соответствующее повышению интенсивности биолюминесценции. Наблюдалась выраженная изменчивость интегральных величин поля биолюминесценции и его вертикальной структурированности.
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