Congener-specific analysis of the accumulation of polychlorinated biphenyls (PCBs) by aquatic organisms in the maximum turbidity zone of the St. Lawrence estuary, Québec, Canada.

The polychlorinated biphenyl (PCB) contamination of the biota of the St. Lawrence estuary maximum turbidity zone (MTZ) was investigated. The species analyzed consist of zooplankton (mostly Neomysis americana), larval smelt (Osmerus mordax), juvenile smelt, juvenile tomcod (Microgadus tomcod) and adult smelt, tomcod and capelin (Mallotus villosus). A significant increase in total PCB contamination from zooplankton to all fish developmental stages indicates that the St. Lawrence MTZ is a site of significant PCB contamination. The total PCB contamination of adult smelt and tomcod sampled in the St. Lawrence MTZ was greater than the limit of 0.1 ppm set by the International Joint Commission for the protection of predators. For zooplankton, tomcod and capelin, significant correlations were found between lipid content and PCB contamination. The congener-specific analyses showed that the bioconcentration factor of the individual congeners varied with the species involved and with the molecular structure of the congener. It was found that the chlorine atoms in positions 2, 4 and 5 on at least one phenyl ring of the PCB molecule was a dominant factor causing accumulation of PCBs in aquatic organisms. The pattern of PCB congeners found in beluga (Delphinapterus leucas) whale tissues is similar to the PCB pattern found in the St. Lawrence estuary MTZ biota.

[Effect of storage and handling on the fatty acid composition of the Antarctic krill Euphausia superba]. / Vliianie khraneniia i teplovoi obrabotki na sostav zhirnykh kislot lipidov antarkticheskogo krilia Euphausia superba.

Gas liquid chromatography and chromato-mass-spectrometry were used to study and compare the fatty acid composition of lipids from the Antarctic krill Euphausia superba shortly after catch and after storage for 6 months in the frozen form or thermally treated and then frozen. Fatty acid lipids were found to contain acids having a methyl group in the 2d position, and acids having an OH group in the 2d and 3d positions, which had not been reported before. The technological treatment did not produce any changes in fatty acid composition which might affect the biological value of the product under consideration.

Preliminary observations on californium-252 behaviour in sea water, sediments and zooplankton.

We carried out radiotracer experiments on the behaviour of 252Cf in the marine environment. The particulate fraction of californium in sea water approached 45% after four days. Californium rapidly adsorbed onto marine coastal and deep-sea sediments with Kd values from 1.4 X 10(4) to greater than or equal to 1 X 10(5). The concentration of 252Cf in euphausiids reached near-equilibrium factors of 3 X 10(2) in water after one week; in contrast, the assimilation from food was very low. Excreted fecal pellets, molts and zooplankton carcasses are potentially important vectors for californium re-distribution in the oceans.

[Hg, Pb and Cd in zooplankton from an area of the Adriatic opposite the Romagna coast line]. / Hg, Pb e Cd in zooplancton di un'area dell'Adriatico antistante il litorale Romagnolo.

The concentrations of heavy metals Hg, Pb and Cd found in zooplankton samples collected in two stations off Cesenatico (Northern Adriatic Sea) from March 1978 to January 1979, have been reported. The Hg, Pb and Cd concentrations showed large variations which did not seem to be correlated with taxonomic composition. The detected levels of metals were higher at the offshore than the nearshore station, accordingly with the sediment pattern. The high concentration of Hg were apparently associated with sources of local industrial pollution.

Some new data on the distribution of benzo (a) pyrene in fresh water and seawater.

Data on the content of benzo(a)pyrene (BP) in various bodies of water in the Estonian SSR including lakes of agricultural regions, lakes and rivers in industrial areas, bodies of water in the National Park and nature protection areas used for drinking water supply, sea gulfs and bays used for recreation are reviewed. Some data on the distribution of BP in bottom sediments and biota of the aqueous medium as well as the accumulation of BP in various organs and tissues of different species of fish are reported. It has been found that the BP level in the bodies of water of the Estonian SSR is relatively low, the highest BP content has been found in seawater, but even there the average concentration of BP was below the safety limit for BP in bodies of water (0.005 microgram/l). Bottom sediments, algae, higher waterplants, zooplankton and fish accumulate BP where its content is about 1,000-100,000 times higher than in water.

Movement generated by interactions between the dense material at the ends of microtubles and non-actin-containing microfilaments in Sticholonche zanclea.

Axopods of the planktonic protozoan, Sticholonche, are used as oars to propel the organism through seawater. Within each axopod is an orgainzed array of microtubules which inserts into a dense material that assumes the form of the head of a hip joint. This material, in turn, articulates on the surface of the nucleus. Microfilaments, 20-30 A in diameter, connect the dense material associated with the microtubules to the surface of the nucleus, and they move the axopod by their contractions. The active phase of the movement may take as little as about 0.04 s and the recovery phase may take between 0.2 and 0.4 s. The microfilaments are not actin, as based on: (a) their small diameter, (b) the lack of decoration with heavy meromyosin, and (c) their ability to coil, spiral or fold during contraction. By the use of Thorotrast, we were able to demonstrate that the cell surface is deeply infolded, extending all the way to the hip joint. Here, there is a specialized membrane system that resembles the diad in skeletal muscle. From cytochemical tests and the use of ionophores and chelators, there is some evidence that the motile process may be controlled by calcium. This study demonstrates that, in at least one system, microtubules can be moves by contractile microfilaments attached to the dense material at there tips.

Residues of PCB's and DDT in the western Lake Superior ecosystem.

Fish from western Lake Superior (1972-73) contained DDT and PCB residues at concentrations greater than o.1 ppm. The most predominant PCB's were those containing 3 to 6 chlorine atoms per molecule, and GLC data indicated that the mixtures were most like the commercial product Aroclor 1254(2). Other chlorinated contiminants identified by GC/MS analyses and occurring at concentrations less than 0.1 ppm were hexachlorobenzene (C6Cl6), chlordane, nonaclor, and dieldrin. Lindane, which has been previously reported in Lake Superior, was below the detection limit of approximately 0.01 ppm. The relationship between the size of lake trout and the concentration of total DDT in the fish was compared to measurements reported in previous studies. The comparison suggests that DDT residues have declined since 1968. The concentration of PCBs was estimated to be 0.8 ng/L in Lake Superior water and 0.1 ppm in large zooplankton. The apparent bioconcentration factor for PCBs in Lake Superior fish ranged from 10(5) to 10(6). The concentration of total DDT and PCBs in the larger Lake Superior fish exceeded the 5 ppm tolerance level established by the U.S. Food and Drug Administration for these chemicals in fish tbe used for human consumption.

Trace metal concentrations and partitioning in zooplankton, neuston, and benthos from the south Texas outer continental shelf.

A variety of marine biota, including zooplankton, sargassum, surface plankton, squid, shrimp, and fish collected along the south Texas Outer Continental Shelf, were analyzed for Cu, Zn, Cd, Pb, Cr, Ni, Fe, and Mn. Although there is a great deal of variation in the chemical content of the various samples, both within species and between species, the variations all fall within the range of values published for similar organisms collected elsewhere. An increase in Pb concentration from north to south, and an increase in Cd concentration from nearshore to further offshore in the zooplankton mirrors the sediment patterns. Statistical analysis of the chemical and biological data for these samples indicates that relatively small percentages of the biological makeup of the sample can markedly affect the concentrations of Pb, Cd, Ni, and Zn. This is particularly true for the larvacea, ostracoda, and mollusca. Chemical analyses of the exoskeletons of shrimp and the skin of both squid and fish indicate that they generally contain higher metal levels in comparison with the flesh from the same organism. This is probably the result of either adsorption from seawater and/or an internal detoxification procedure employed by the organism. The analysis of a composite sample of squid 'pens' indicates that they contain enriched Cu, Cd, Zn, Pb, and Fe levels in comparison with the skin and flesh. These elevated levels are probably the result of an internal detoxification procedure and/or may represent a means of storing necessary metabolites, at least in the case of Cu and Zn, but can not be attributed to adsorption as the chitinous 'pen' is imbedded in tissue and is not directly exposed to seawater.