Bruce W. Tripp

Hydrocarbons in western North Atlantic surface sediments

High concentrations of hydrocarbons (500–3000 μg/g dry weight) together with a complex and wide molecular weight range of composition, and low 14C activity of δ14C = −833 ± 50%. strongly indicate that fossil fuel hydrocarbons make up the bulk of hydrocarbons in and near the New York Bight dump site areas. The composition and concentrations of hydrocarbons in Hudson Channel sediments suggest some transport of dump site hydrocarbons to areas in the channel midway to the edge of the continental shelf. Sediments at 16 stations in other areas of the continental shelf, continental slope and abyssal plain have hydrocarbon concentrations and compositions indicating that no more than 1 μg/g dry weight of fossil fuel hydrocarbons are present. N-alkanes from land sources were among the most predominant hydrocarbons in all samples except those in the New York Bight region. Their presence in abyssal plain surface sediments documents transport of some land derived organic matter to these deep ocean areas. Two 25-carbon cycloalkenes are among the more predominant hydrocarbons in continental shelf surface sediments except for the dump site areas. These two compounds are present in lower concentrations in slope sediments and are not detected in abyssal plain sediments.

Trace organic contamination in the Americas: An overview of the US National Status & Trends and the International ‘Mussel Watch’ programmes

Abstract The National Status & Trends (NS&T, 1986–1993) and the International Mussel Watch (IMW, 1991–1992) programmes provide a good coverage of a broad range of environmental conditions along the North, Central and South American coasts. Total concentrations of DDTs, chlordane-related compounds, PCBs and PAHs present fairly homogeneous distributions along the northern Gulf of Mexico coast, with very few sites showing extremely high or low concentrations. In contrast, a larger variability in the geographical distribution of some of these organic contaminants was observed for IMW sites. For example, high concentrations of DDT and its metabolites, DDD and DDE, were generally found in tropical and subtropical areas as compared to more temperate zones of South America. ‘Industrial’ contaminants, such as PCBs and PAHs, have similar distributions with the highest concentrations encountered generally along the southern South Atlantic coast. An overall comparison of the concentrations of these organic contaminants measured at NS&T and IMW sites indicates that contamination is significantly higher along the northern coast of the Gulf of Mexico.

Organic matter fluxes from sediment traps in the equatorial Atlantic Ocean

The vertical flux of particulate organic matter to the ocean floor is controlled by complex remineralization and transport processes. Rapidly sinking, large (>32 µm) particles may account for most of the vertical mass flux1–3. Experiments involving collection of sedimenting particles in traps deployed at varying depths in the water column provide a way of assessing these processes directly2–12. Measurement of organic carbon content of trap material may lead to a general understanding of the flux of particulate organic matter to the sea floor3,8–10. However, details of the transport and transformation phenomena involving sinking particulate organic material can be elucidated only by determining distributions of specific organic compounds associated with the particles11,12. We report here direct flux measurements and composition of lipids obtained by organic geochemical studies of particulate material collected in a deep-sea moored sediment trap experiment in the equatorial Atlantic Ocean.

Hydrocarbons in cores of northwestern Atlantic coastal and continental margin sediments

Abstract The concentrations and composition of hydrocarbons in sections from a 210 Pb dated core from Buzzards Bay, Massachusetts are reported. Terrigenous n -alkane concentrations remain constant throughout the 62 cm and 195 years sampled. Gas Chromatographic analysis on SCOT columns revealed an unresolved complex mixture of alkanes and cycloalkanes which decreases in concentration with increasing depth. Phenanthrene and C 1 and C 2 substituted phenanthrene concentrations also decreased with increasing depth and the relative abundance of C 1 and C 2 homologs compared to phenanthrene suggest a pyrolytic origin for these aromatic hydrocarbons. The various sources of hydrocarbons in surface sediments and the processes which could govern their distribution are discussed. The most likely source of the phenanthrenes and the unresolved complex mixture of alkanes and cycloalkanes in the upper core sections circa 1900 to the present seems to be urban air fallout. A depth distribution of alkanes and cycloalkanes similar to the Buzzards Bay core was found for a second area of Buzzards Bay and for cores from sediments of the Gulf of Maine and Hudson Canyon. Two C 25 cycloalkenes were identified as major hydrocarbons in the sediments. Their concentrations decrease with increasing depth in the cores. Mass spectra of these compounds and their hydrogenation products are reported.

The west falmouth oil spill after 20 years : fate of fuel oil compounds and effects on animals

Abstract The barge Florida spilled No. 2 fuel oil into Buzzards Bay, Massachusetts on 29 September 1969. Sediments from five of the original stations were sampled in August 1989 and analysed for fuel oil hydrocarbons. Two subtidal and one intertidal marsh station showed no evidence of fuel oil. One subtidal mud core had traces of biodegraded fuel oil at 10–15 cm. One marsh core contained 10 −6 g g −1 dry wt of weathered and biodegraded fuel oil aromatic hydrocarbons and cycloalkanes at 5–10 cm with lesser concentrations at 0–5 and 10–15 cm. Although present in trace concentrations, these hydrocarbons appear to be slightly inducing cytochrome P4501A in marsh fish ( Fundulus heteroclitus ).

Transport of sludge-derived organic pollutants to deep-sea sediments at deep water dump site 106

Linear alkylbenzenes (LABs), coprostanol and epi-co-prostanol, were detected in sediment trap and bottom sediment samples at the Deep Water Dump Site 106 located 185 km off the coast of New Jersey, in water depths from 2400 to 2900 m. These findings clearly indicate that organic pollutants derived from dumped sludge are transported through the water column and have accumulated on the deep-sea floor. No significant difference in LABs isomeric composition was observed among sludge and samples, indicating little environmental biodegradation of these compounds. LABs and coprostanol have penetrated down to a depth of 6 cm in sediment, indicating the mixing of these compounds by biological and physical processes

“Mussel Watch”—Measurements of Chemical Pollutants in Bivalves as One Indicator of Coastal Environmental Quality

The utility of the bivalve sentinel organism approach to monitoring for some chemicals of environmental concern in coastal and estuarine areas has been evaluated by regional and national programs and by smaller-scale research efforts during the past 15 years. The extent and severity of coastal contamination by chemicals such as polychlorinated biphenyls, chlorinated pesticides, trace metals, and plutonium was assessed in several bivalve sentinel organism programs. Advantages and limitations of this approach are presented and discussed briefly within the context of both national and international efforts.

Aromatic hydrocarbons in New York bight polychaetes: ultraviolet fluorescence analyses and gas chromatography/gas chromatography-mass spectrometry analyses

Polychaetes collected from New York Bight sediments near sewage sludge and harbor dredge spoil dump sites contained a series of diaromatic-tetracyclic hydrocarbons of apparent triterpenoid origin. Microbial processes in sewage sludge are a likely source of these compounds. These octahydrochrysenes were much more abundant in the polychaetes than were the fossil fuel and combustion-derived polycyclic aromatic hydrocarbons which were found in the sediments, presumably because they are more available for biological uptake. If the polychaetes had been analyzed only by the spectrofluorometric techniques often used for screening samples for petroleum contamination, then grossly inaccurate results for aromatic hydrocarbon content would have been obtained. Therefore, UV fluorescence must be used in a heirarchical approach, with more sophisticated procedures available to verify the petrogenic nature of the hydrocarbons.

Unburned coal as a source of hydrocarbons in surface sediments

Abstract The isolation and quantification of the various sources of trace levels of hydrocarbons in environmental samples is a difficult analytical task. Based on the hydrocarbon concentrations found in non-polluted surface sediment and an estimate of the amounts of coal particles found in similar areas we conclude that unburned coal can be a significant source of sediment hydrocarbons in the coastal marine environment.

Biogeochemistry of aromatic hydrocarbons in the benthos of microcosms

Investigations into the fate of petroleum compounds in the marine environment were carried out using experimental microcosms of two sizes and designs. Aromatic hydrocarbons or No. 2 fuel oil were spiked to the water of a 13 m3 continuous flow system and to a 2281 recycled flow system. The transport and alteration of this oil was traced in the sediment and benthic organisms (Glycera americana, Crepidula sp., and Nephtys incisa) of these microcosms. Measurable contamination was found in both sample types. The aromatic hydrocarbon distribution, including relative isomeric distribution (e.g., C2‐phenanthrenes) was found to be different in sediment and in organisms from that which was originally introduced to the experimental microcosm. Differences in isomer distribution between Glycera and Crepidula were also detected. Based on the experimental data: molecular weight and specific isomeric form, biochemical processes, solubility, and particle adsorption/desorption influence the fate of petroleum compounds in b...