The hazard of a two-level synergism of synecological summation of anthropogenic effects.

Abstract

There are a number of approaches to identificationand classification of the hazards of anthropogenicimpact on organisms, populations, ecosystems and thebiosphere [1–7].The purpose of this study was to identify a new typeof ecological hazard of anthropogenic impact (usingchemical pollution as an example), which we proposeto term “synecological summation” or “synergisticsummation” of anthropogenic effects on organisms oftwo adjacent trophic levels.As s continuation of our studies on the anthropo-genic impact of mixed chemicals, we studied the effectsof some detergents on the filtering activity of thebivalves Crassostrea gigas Thunberg and Mytilus gal-loprovincialis Lam. The organisms were obtained fromthe Institute of Biology of Southern Seas (INBUM),National Academy of Sciences of Ukraine. The methodof measurement was described in [6].The data shown in Tables 1–3 demonstrate that thedetergents Vesna-Delikat, IXI, and Tide-Lemon inhib-ited water filtering by bivalves, including both adult(Tables 1, 2) and juvenile (Table 3) organisms. The con-centrations of the detergents producing this effect wererelatively low. This agrees with similar data on theinhibitory effects produced by low concentrations ofother detergents, as well as of some individual chemi-cals which belong to the class of surfactants [8–10].Note that the same concentrations of detergents andsurfactants did not produce noticeable effects on sev-eral species of unicellular organisms that represented apart of the suspended matter.It was shown that the detergent Tide-Lemon at aconcentration of less than 100 mg/l did not inhibit thegrowth of Synechocystis sp. PCC 6803 [11]. The deter-gents OMO-Intelligent (1, 10, and 100 mg/l) did notinhibit the growth of Anacystis nidulans ( Synechococ-cus elongatus ) R-2 [12]. Moreover, the detergent Tide-Lemon at concentrations of 1–100 mg/l stimulated thegrowth of Synechocystis sp. PCC 6803 and Scenedes-mus quadricauda [11] in some growth media; the deter-gents TL (10 mg/l) and E (10 mg/l) stimulated thegrowth of A. nidulans [12]. Stimulation of some otherspecies of phytoplankton (marine microalgae) was alsoshown [13].Various species of phytoplankton were shown tohave different sensitivities to surfactants. It was shownthat the diatom Thalassiosira pseudonana is relativelysensitive to the nonionic surfactant Triton X-100 [14].However, the entire set of data available allows us toconclude that at least some species of phytoplanktonare relatively tolerant to detergents and their compo-nents (several surfactants), at concentrations that sig-nificantly reduce the water filtering activity of bivalves.The reduction of the filtering activity is associated witha decrease in the ability of bivalves to remove sus-pended particles from water.The actual chemical pollution of water bodies is acomplex pollution with a whole range of chemicals.Therefore, it is important that this range of chemicalsmay include both surfactants and nutrients, e.g., phos-phorus. Many detergents include both surfactants andphosphorus-containing chemicals; hence, they are per-fect examples of the source of the double contamina-tion of water with both components. This fact is inaccord with the aforementioned stimulation of thegrowth of some phytoplanktonic species by detergents(because the stimulatory effect of phosphorus mightsometimes be more pronounced than the inhibitoryeffects of the other chemicals in the mixture).In actual ecological systems, the two group oforganisms considered (phytoplankton and bivalves) arelinked together in trophic chains. Therefore, differenttypes of responses of phytoplankton and bivalves tosome chemicals that simultaneously occur in water(under the conditions of complex water pollution, orpollution with a mixture of chemicals) may bring aboutconsequences important to the state of the ecosystem.Because of the link between the two trophic levels,the hazards of individual chemicals that affect individ-ual trophic levels may be combine to yield the follow-ing effects: first phosphorus may stimulate the growthof phytoplankton; second, the control of phytoplankton(via its removal from water consumers) is disturbed