Robert W. Risebrough

PCB and PCT contamination in Winter Quarters Bay, Antarctica

Winter Quarters Bay at McMurdo Station in Antarctica provides docking facilities to visiting ships and is adjacent to a former dump site. Sediments are heavily contaminated with a tarry material and contain a moderately high level of chlorinated biphenyls, in the range of 100–1400 ng g−1 dry wt. Composition in most samples is identical to that of Aroclor 1260, with no evidence of partial degradation, indicating a dominant point source of contamination. Chlorinated terphenyls, also with a 60% chlorine composition, are present at levels in the order of 30–1200 ng g−1. Outside Winter Quarters Bay, PCB levels decrease sharply, by two orders of magnitude over 1 km, and four orders of magnitude at stations 9 and 15 km distant. A substantial modification of the congener composition is evident at the distant stations, but the McMurdo PCB ‘signature’ nevertheless dominates over the ‘global’ signature characteristic of PCBs in the global atmospheric circulation.

Identification of tris(chlorophenyl)methanol in blubber of harbor seals from Puget Sound

Abstract A compound detected in extracts of blubber of harbor seals, Phoca vitulina , found dead in Puget Sound in the north-western United States over the period 1972–1982 was identified as tris (chlorophenyl)methanol from its mass spectral characteristics and by synthesis. Concentrations in harbor seal blubber ranged from 23 to 750 ng/g of the lipid weight and showed no evident changes over the time interval of the study. Concentrations were highly correlated with those of most of the other organochlorines detected in the harbor seal extracts, indicating a similar pattern of uptake and accumulation. The compound is used in the manufacture of optically active polymers, which appear to be a plausible source.

Estimated inputs of organochlorines from the River Ebro into the northwestern Mediterranean

Abstract Measurements of organochlorines in the particulate and dissolved phases of water of the River Ebro in northeastern Spain, sampled at the mouth at four periods over 1982–1983, are combined with data on daily flows to produce estimates of the inputs of these compounds into the northwestern Mediterranean from this source. Hexachlorobenzene (HCB) was the most abundant of the compounds detected, with an estimated yearly input of 30 kg, followed by PCBs, with a yearly input on the order of 12 kg. The HCB and PCBs are attributed principally to a manufacturing facility on the river. Other estimated yearly inputs are 8 kg of total DDTs, 1 kg each of dieldrin, endrin, and endosulfan, and 2 kg of the total of the several chlordane compounds. Relatively high levels of p,p′-DDT among the DDT compounds indicated recent use or mobilization of DDT. These estimates of river inputs of these contaminants are substantially lower than those used or derived in several recent reviews of contamination problems in the Mediterranean; they support the conclusions of other studies that the principal dispersal pathway of the organochlorines is the atmosphere.

Red-Pelaged Harbor Seals of the San Francisco Bay Region

Harbor seals of San Francisco Bay, California, have a higher incidence of red pelage (range, 4–32% of the total count) than is observed along the outer eastern-Pacific coast or elsewhere in the world. Red pelage was observed among all sex and age classes, except for pups. The pattern of red coloration on the body varied; most seals had red hair extending from the head down to the shoulder. Elemental analyses of hair samples revealed that red coloration was from deposition of iron oxide precipitates on the hair shaft. We postulate that the particular conditions within San Francisco Bay, including large areas of shallow water and strong summer winds with resuspension of sediments, bring sufficient quantities of ferrous iron from the sediments into the water column where it may serve as a principal source of the ferric oxide deposited on pelage of seals.

Southern California Outer Continental Shelf Baseline Studies: Intercalibration of Participating Hydrocarbon Laboratories

As part of the Bureau of Land Managements Outer Continental Shelf Baseline Program in the Southern California Bight, a total of five different Hydrocarbon laboratories were involved in the analytical effort to measure petroleum hydrocarbons in marine samples. In this paper, we present the results of intra and inter-laboratory calibration exercises. These data demonstrate that comparable results can be generated by different environmental laboratories through careful adherence to established and controlled laboratory protocol and diligent efforts to intercalibrate the laboratories through varied sample exchange. Clearly, continued attention must be paid toward developing improved methodology for pollutant monitoring; however, our data illustrate a significant improvement in intra and inter-laboratory precision over other OCS programs to date.