Other Aquatic Organisms

In crustaceans, Coig/Csed ratios decreased with decreasing hydrophobicity the opposite occurred in eels and is attributed to differences in uptake efficiencies and low elimination rates of lower chlorinated congeners in cmstaceans. 

A correlation exists between the concentration of hpophihc, hydrophobic, chlorinated hydrocarbons in benthic fishes and the concentration of these compounds in sediments. The correlation is affected by the solubility of the contaminants, as reflected by the octanol-water partition coefficient Kov/ and the carbon content of the sediment. One study concluded that surface sediments, which change more slowly than the water column, are useful for averaging spatial and temporal contaminant inputs however, correlations between PCB concentrations in sediment and those in non-benthic carnivores with limited home ranges are extremely variable. PCBs in a tidal creek in Georgia were traced to Aroclor 1268 used at a former chloralkali plant near the creek. Sediment-ingesting forage fishes, such as the striped mullet (Mugil cephalus), efficiently accumulate PCBs and are an important link in the food web transfer of sediment-associated contaminants. 

Variations in PCB concentrations in sediment and water in the Great Lakes can largely account for the variability in fish PCB residues between different bodies of water. 

The upper Hudson River was massively contaminated with PCBs from an industrial plant for several decades prior to 1975. All fishing in this section in 1976 was harmed because of PCB contamination. The prohibition is still in effect because, in part, of measurable PCB residues in caged fishes from this area. Striped bass Morons saxatilis) collected near Troy and Albany, New York, contained higher concentrations in muscle of PCB 77 (37.0 xg/kg FW) and PCB 126 (8.0 xg/kg FW) than con-specifics from other locations in New York. Almost all (99%) the PCB toxicity in muscle of striped bass was attributed to PCBs 77,105 (62.0 xg/kg FW), and 126. 

Concentrations of PCBs in female northern pike (Esox lucius) from a Scandinavian lake 

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There are several species of fish and other aquatic organisms susceptible of being used as pollution sentinels in the Ebro River (Table Species). However, none of them is present in all sites shown in Fig. 1, at least in enough abundance. From Barbastro to Flix (including the Riba-roja dam), barbel and bleak were preferred for chemical and pollution marker analyses whereas carp (Cyprinus carpio), European catfish (Silurus glanis), and roach (Rutilus rutilus) were the main species sampled in... 

Endrin released to water will adsorb to sediments or bioaccumulate in fish and other aquatic organisms. Both bioaccumulation and biomagnification of endrin were reported to occur in an aquatic laboratory microcosm system (Metcalf et al. 1973). In terrestrial ecosystems, endrin transformation products (endrin ketone, endrin aldehyde, and endrin alcohol) have been measured in plants grown on endrin-treated soil (Beall et al. 1972 Nash and Harris 1973). 

A number of methods can he used to control thermal pollution. Many environmentalists point out that one approach is for consumers and industries simply to reduce the amount of electricity they use and waste, allowing power plants to reduce the amount of electricity they generate. Another approach is to discharge heated water in places that are less ecologically sensitive, that is, bodies of water that contain fewer hsh, shellhsh, and other aquatic organisms that are affected by heated water. For example, heated water can he used to heat homes, office buildings, and other structures. 

The second example includes the influence of sorption and sediment-water interaction, processes which were not relevant for the case of chloroform. We choose the real case of a chemical pollution of the River Rhine. On November 1, 1986, a fire destroyed a storehouse at Schweizerhalle near Basel (Switzerland). During the fighting of the fire, several tons of various pesticides and other chemicals were flushed into the River Rhine (Wanner et al., 1989). One of the major constituents discharged into the river was disulfoton, an insecticide. An estimated quantity of 3.3 metric tons reached the river within a time period of about 12 hours leading to a massive killing of fish and other aquatic organisms. 

DISOLVED OXYGEN (DO). One t>r the- most important indicators of the condition of a water supply for biological, chemical, and sanitary investigations. Adequate dissolved oxygen is necessary for the life of fish and other aquatic organisms, and is an indicator of corrosivity or water, photosynlhctie activity, septieity. etc. 

Food Chain Bioaccumulation. The data available indicate that silver can bioconcentrate to a limited extent in algae, mussels, clams, and other aquatic organisms. However, many of the studies that were performed do not conform to the current state of the art in terms of sample size, duration, and analysis of contaminant levels in aquaria. Reliable data would be useful in determining the possibility of biomagnification and in defining pathways for general population exposure, as well as in estimating exposures from NPL site contamination. 

A few studies (Kukkonen et al., 1989 Kukkonen and Oikari, 1991 Muir et al., 1994) have reported an enhancement of organic contaminant bioavailability to various organisms. In all cases this occurred at low DOM concentrations (< 10 mg/L carbon). Currently, a specific mechanism has not been determined, but Muir and co-workers (1994) have suggested that organic mucus in fish can act in a manner similar to that of DOM and bind contaminants. They observed lower than expected bioaccumulation of pyretheroids in control studies followed by an enhancement with the addition of small amounts of DOM. Nonetheless, this does not explain the enhanced bioaccumulation observed for other aquatic organisms. 

The mean assimilation quotient as regards fish and other aquatic organisms is 0.8 (Vinberg, 1956). It was and still is widely used for calculating consumption or assimilation of food. 

Cangiano, T., Dellagreca, M., Fiorentino, A., Isidori, M., Monaco, P. and Zarrelli, A. (2002) Effect of ent-labdane diterpenes from Potamogetonaceae on Selenastrum capricornutum and other aquatic organisms, Journal of Chemical Ecology 28 (6), 1091-1102. 

The results obtained from the phytochemical study of P. natans and R. maritima suggest that the high concentrations of the bioactive diterpenes found in these plants could interfere with other aquatic organisms, thus playing a role in the equilibrium of the aquatic systems. 

The speciation of Hg in all kinds of environmental matrices (air, water, sediment, and seafood/fish) has been studied for several years now and it is still a hot topic in ongoing studies. Different environmental compartments show different ratios between the abundance of species for example, for natural waters the abundance of Me-Hg and Hg2+ depends on the geological origin and the pretreatment (filtered or not filtered). From less than 1 percent [13] to around 5 percent [14, 15], especially for unfiltered seawater, Hg as Me-Hg has been reported. While phytoplankton contains around 15 percent, in zooplankton around 20 percent of total Hg is present in the form of Me-Hg [15, 16]. In foods they can occur as different species, normally in trace amounts. The level of Hg in the environment is generally low, but there are some species with a greater tendency to accumulate. The accumulation of Hg species is higher in fish than in any other aquatic organisms. The contribution of Me-Hg increases in herbivorous fish to approximately 70 percent [17], while in predatory fish a maximum of nearly 100 percent... 

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