Biota estuarine

Lead is toxic to all phyla of aquatic biota, but its toxic action is modified by species and physiological state, and by physical and chemical variables. Wong et al. (1978) stated that only soluble waterborne lead is toxic to aquatic biota, and that free cationic forms are more toxic than complexed forms. The biocidal properties of soluble lead are also modified significantly by water hardness as hardness increases, lead becomes less bioavailable because of precipitation increases (NRCC 1973). In salmonids, for example, the toxicity and fate of lead are influenced by the calcium status of the organism, and this relationship may account for the reduced effects of lead in hard or estuarine waters. In coho salmon (Oncorhynchus kisutch), an increase in waterborne or dietary calcium reduced uptake and retention of lead in skin and skeleton (Varanasi and Gmur 1978). 

Reported concentrations of non-ionic surfactants and their metabolites in marine and estuarine biota... 

The last include wet and dry deposition of particles and solutes and gas exchange across the air-sea interface. Because of proximity to source, coastal waters tend to be more polluted than the open ocean. A notable exception is the worldwide acidification of surface waters caused by CO2 emissions. Of all the coastal waters, estuaries tend to be the most impacted. This is due to high rates of pollutant loading and to natural processes that act to concentrate these pollutants in the local sediments and biota. This is most unfortunate as estuarine waters support the world s largest fisheries and are where recreation is concentrated. 

Pereira WE, Rostad CE, Chlou CT, et al. 1988. Contamination of estuarine water, biota, and sediment by halogenated organic compounds A field study. Environ Sci Technol 22 772-778. 

Moreover, both river induced up-welling and river discharge of nutrients create a fertile environment which enhances the primary production of organic matter in off-shore direction of estuaries. It can be predicted from these observations that heterogeneous reactions between dissolved and both mineral phase and biota will be predominant in estuaries and coastal zones. These reactions will primarily affect those elements and compounds which are located at the particulate surface. The determination of surface properties of particles appear to be an important key to understand the interactions of trace elements and organic compounds between particulate and dissolved phases in estuarine and coastal systems. 

Kannan, K., M. Kawano, Y. Kashima, M. Matsui, and J.P. Giesy. 1999. Extractable organohalogens (EOX) in sediment and biota collected at an estuarine marsh near a former chloralkali facility. Environ. Sci. Technol. 33 1004—1008. 

PROBABLE FATE photolysis, may be important, but is probably impeded by adsorption, photooxidation by U.V, in aqueous medium (Ty 90-95°C time for the formation of CO, (% of theoretical) 25% 75.3 hr, 50% 160.6 hr, 75% 297.4 hr, photooxidation half-life in air 6.81 hrs-2.i du>s, degrades quickly by photochemically produced hydroxyl radicals, with an estimated half-life of 29 hr oxidation-, chlorine and/or ozone in sufficient quantities may oxidize fluorene hydrolysis, not an important process volatilization probably not an important transport process, volatilization half-lives from a model river and a model pond 15 and 167 respectively sorption adsorption onto particles, biota, and sediments is probably the dominant transport process, half-life in soil ranges from 2-64 days biological processes bioaccumulation is short-term, metabolization and biodegradation are very important fates in estuarine waters 15pg/L, 12% adsorbed on particles after 3 hr... 

Ibelings, B.W., Havens, K.E., 2008. Cyanobacterial toxins a qualitative metaanalysis of concentrations, dosage and effects in freshwater, estuarine and marine biota In Hudnell, H.K. (Ed.), Cyanobacterial Harmful Algal Blooms State of the Science and Research Needs. Advances in experimental medicine and biology, vol. 619, Springer, New York, pp. 675-732. 

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