KHOLODKEVICH S.V., KUZNETSOVA T.V., IVANOV A.V., LYUBIMTSEV V.A., KHALATOV A.N., KURAKIN A.S., KORNIENKO E.L. , TRUSEVICH V.V. , GNYUBKIN V.F.

Scientific Research Centre for Ecological Safety RAS, Russia, Кaradag Natural Reserve NAS of Ukraine, Ukraine

Recently for continuous ecological monitoring of aquatoria in regions of oil and gas development in Russia and abroad methods and technical systems based on recording of physiological or behavioral responses of aboriginal benthic invertebrates are intensively used [1-4].

The main aim of this work was to investigate the dynamics of cardiorhythm (heart rate - HR) and mussels valve movement recorded simultaneously under changes of physical and chemical factors of the environment. Model organic toxicant and short-term (1 hour) rapid decrease of salinity were used as toxic and non-toxic chemical stressors.

The authors pointed out that the preliminary selection of relevant groups of test-organisms for further ecotoxicological investigations by testing them with the use of a number of “standardized” physical and chemical stimuli was necessary. It was shown that rapid short-term variation of salinity can be used as one of the standard stimuli to select relevant groups of test-organisms. For this purpose the rapid variation of water temperature and “shadow-light” stimulus may also be recommended [5]. For all such physical and chemical stressors all of tested mussels showed common behavioral reaction – closure of valves (which led to isolation of mussels from aggressive external medium). The process is accompanied by initial rapid increase of the HR - the first non-specific response of mussels cardiac system for such stressor, followed gradual bradycardia in mussels with closed valves.

In this paper there was revealed that the end of valve closure process, as the response for chemical stressors, corresponded to maximum of HR – the first stage of stress response of cardiac system. In the case of uninjuring influence – variation of water salinity – the reaction of valve opening in washing period and the beginning of HR recovery coincide, whereas for damaging influence the beginning of HR entrainment forestall the process of active valve opening for several hours. This fact can be linked with desensitization of chemosensory structures as a response for strong toxic effect.

The obtained data demonstrate that valve movements and characteristics of cardiac activity registered simultaneously will increase effectiveness and reliability of organism functional state assessment under changes of the environment. Thus biomonitoring systems based on such simultaneous recording are more perspective for industrial ecological monitoring particularly in oil and gas industrial active zones.

References

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Kholodkevich S.V., Fedotov V.P., Kuznetsova T.V., Ivanov A.V., Kurakin A.S., Kornienko E.L. Fiber-optic remote biosensor systems for permanent biological monitoring of the surface waters quality and bottom sediments in the real time // http:/www.ices.dk/products/CMdocs/CM-2007/I/I-2007.pdf.
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Kholodkevich S.V., Kuznetsova T.V., Trusevich V.V., Kurakin A.S., Ivanov A.V. Peculiarities of valve movement and cardiac activity of bivalves during toxic and non-toxic chemical stressors exposure. // Doklady Akademii Nauk – in press.

OIL AND GAS OF ARCTIC SHELF 2008