E.S. Van Vleet

Lipid composition of twenty-two species of Antarctic midwater zooplankton and fish

Total lipids, hydrocarbons, wax esters, triacylglycerols, and phospholipids were determined for 22 major biomass species of zooplankton and fish in an Antarctic mesopelagic community that were collected in 1982 and 1983. Lipid levels were similar to levels in more temperate mesopelagic species. Total lipid concentration was depth related, with all lipid-rich species being collected at depths greater than 230 m. Wax ester content in copepods (60 to 70% of the total lipid) was generally higher than in subtropical species. Lipids indicated three predator-prey relationships (Parandania boecki-Atolla wyvillei, Thysanoessa macrura-Calanoides acutus andEurythenes gryllus-Atolla wyvillei). These were confirmed by gut content analyses. The mesopelagic fishBathylagus antarcticus, Pleuragramma antarcticum, andProtomyctophum bolini stored most lipid intramuscularly, whereasElectrona antarctica andGymnoscopelus nicholsi contained extensive stores in subcutaneous lipid sacs. The intramuscular lipids inP. antarcticum and the subcutaneous lipid sacs ofE. antarctica were primarily wax esters, possibly used for increased buoyancy or long-term energy storage. Unlike the odd-carbon preference of aliphatic hydrocarbons which typifies terrestrial plants and temperate marine organisms, even-carbon chain-length paraffins predominate in 80% of the Antarctic species analyzed. Although the source of these even-carbon n-alkanes cannot be determined from our data, their dominance in the species analyzed suggests that an unusual biochemical pathway may be responsible for their synthesis in this ecosystem.

Coprostanol (5β-cholestan-3β-ol) in lagoonal sediments and mussels of Venice, Italy

Coprostanol, a fecal sterol indicative of mammalian waste, was analysed in sediments and mussels collected from 25 stations in the canals and lagoon of Venice, Italy, to investigate dispersal and accumulation of untreated sewage. Concentrations of sedimentary coprostanol ranged from 0.2 μg g−1 in a reference station in the northern Adriatic Sea to 41 μg g−1 in an interior canal of Venice. These values made up 4% to 44% of the total sterols, and indicated which areas of the lagoon had the greatest contribution from sewage discharge. Coprostanol concentrations found in mussels were lower and less variable than in sediments, indicating that sedimentary coprostanol concentrations are a better indicator of sewage discharge in the lagoon. Areas with high sedimentary coprostanol concentrations either lacked mussels entirely or contained mussels showing severe environmental stress. Data suggest that sedimentary coprostanol concentrations appear to be a useful indicator of potential ecological problems in the lagoon and canals of Venice due to the direct input of untreated waste.

Clam Transplantation and Stress-Related Biomarkers as Useful Tools for Assessing Water Quality in Coastal Environments

In this study, the Active BioMonitoring (ABM) approach has been investigated using species of indigenous (from a pristine site) and transplanted (to a polluted area) hard clam Mercenaria mercenaria as an indicator organism of water/sediment pollution in Tampa Bay, Florida, a highly urbanized and industrialized subtropical estuary. A range of possible induced stress indices was selected and used on the basis of potential pollutant toxicity mechanisms including specific enzymatic responses (MFO as BPH and NADPH cytochrome c reductase, antioxidant enzymes as SOD and caltalase, PDH) and general cellular damage (lysosomal latency, histopathological lesions). The organic sediment contamination compared to the animal body burden revealed bioaccumulation activity in transplanted clams. The marked increases of BPH and catalase activities, together with the significant reduction of lysosomal membrane stability in transplanted animals, suggested their potential for application as biomarkers in subtropical coastal pollution monitoring.

Simulated degradation of glyceryl ethers by hydrous and flash pyrolysis

Abstract Hydrous and flash pyrolysis were carried out on phytanyl ethers isolated from a methanogen (Methanosarcina barkeri), a haloalkaphile (Haloalkaphile sp.) and a thermoacidophile (Sulfolobus sulfotaricus). No thermal alteration products of the intact ether lipids were observed below 150°C. From 150–300°C, slight pyrolysis of the intact glyceryl ethers was observed, although recovery of the parent compounds averaged >95%. As pyrolysis temperature increased, the alcohol and aldehyde were the first products formed following direct cleavage of the ether bond. At 600°C, the corresponding alkene also became a dominant flash pyrolysis product. With increases in pyrolysis temperature to 900°C, increasing amounts of volatile alkenes were produced. Based on the observed fragmentation patterns, we suggest that phytanol is first cleaved from the intact glyceryl ethers, followed by degradation of the phytanol to the corresponding alkanes or shorter chain components. In addition, as shown by other investigators, the alteration products may also be directly incorporated into higher molecular weight fractions.

Distribution, sources and fates of floating oil residues in the Eastern Gulf of Mexico

Abstract Pelagic tar was monitored over a two-year period in the Eastern Gulf of Mexico. A total of 416 surface and subsurface samples were collected during monthly cruises. Concentrations of pelagic tar found in the Eastern Gulf of Mexico were substantially higher than values reported for other areas around the world. Tar is primarily associated with the Gulf Loop Current, whereas continental shelf areas are relatively uncontaminated. Grounding of significant amounts of tar occurs primarily along the south-east coast of Florida, between Key West and Fort Pierce. Approximately 10–50% of the tar in the eastern Gulf is transported in from the Caribbean Sea via the Yucatan Straits. The remainder originates within the Gulf. Approximately half of the pelagic tar samples collected during the study appeared to have originated from tanker operations.

Neutral lipid components of eleven species of Caribbean sharks

Eleven species of sharks collected in the Caribbean Sea contained, on a dry weight basis, 21-95% lipid in their livers and 0.4-11% lipid on their muscle tissues. Based upon theoretical calculations, two species of shark (Centrophorus granulosa and Dalatias licha) contained sufficient lipids to allow neutral buoyancy in seawater. In both of the above species, wax esters comprised the major lipid class. Triacylglycerols and hydrocarbons were present in lower concentrations. Deep water sharks generally possessed larger livers containing higher percentages of total lipids and unsaturated hydrocarbons than more shallow dwelling species.

Distribution of coprostanol, petroleum hydrocarbons, and chlorinated hydrocarbons in sediments from canals and coastal waters of Venice, Italy

Abstract In order to evaluate the degree of organic pollution in canals and surrounding coastal waters of Venice, Italy, fecal sterols, petroleum hydrocarbons and chlorinated hydrocarbons were analyzed in twenty-five sediment samples collected from Venetian canals, the surrounding Veneto Lagoon, the industrialized area of Porto Marghera, and the Northern Adriatic Sea. Although the main Venetian canals are at least partially flushed by tides, most canals still have mud bottoms which are ideal for preservation of chemical pollutants. The fecal sterol, coprostanol, was analyzed to evaluate the accumulation and dispersal of untreated waste from the city of Venice. Coprostanol “hotspots” gave indications of where health hazards may exist for local populations. Petroleum hydrocarbon contamination was observed in essentially all areas except the Northern Adriatic. Highest hydrocarbon concentrations were found near Porto Marghera followed by decreasing concentrations in the Venetian Canals and Veneto Lagoon. Based upon alkylated homolog distributions of polycyclic aromatic hydrocarbons, fossil fuel combustion appears to be the major source of these hydrocarbons. Chlorinated hydrocarbons were present in a wide range of concentrations. The spatial distribution of these compounds (HCB, HCH, DDT, and PCB) could be clearly correlated with local inputs.

Sedimentary hydrocarbons from a subtropical marine estuary

Petrogenic, pyrogenic, and biogenic hydrocarbons were determined in sediments from 48 sites around Charlotte Harbor, a relatively undeveloped subtropical marine estuary along the south-west coast of Florida. Hydrocarbon concentrations generally ranged from 1 to 5 μg g−1, which are lower than hydrocarbon values reported for most temperature estuarine sediments, but agree well with values reported for sediments from more highly impacted subtropical estuarine systems. Little evidence of petrogenic or pyrogenic inputs was observed except for certain “hot spots” associated with marina, land development and industrial activities. Sediments collected during the summer showed enhanced hydrocarbon concentrations over winter samples, reflecting increased biogenic input from both marine and terrestrial sources. Data obtained in this, and similar, studies suggests that in these subtropical areas, a steady state is established between hydrocarbon inputs and microbial degradation.

Comparison of anthropogenic hydrocarbon inputs to two subtropical marine estuaries

Abstract Anthropogenic and biogenic hydrocarbons have been determined in approximately 160 sediments, organisms and water samples from Tampa Bay, Florida, a highly urbanized and industrialized subtropical estuary. Results are compared with data from a similar study in Charlotte Harbor, Florida, a relatively unimpacted estuary 93 km south of Tampa Bay. Sedimentary hydrocarbon concentrations in both summer (5–30 μg/g) and winter (0–5 μg/g) are similar in the two estuaries, although levels in both subtropical systems are generally much lower than in most temperate estuaries. We postulate that this difference is the result of both larger average grain size and higher annual temperatures in the subtropical estuaries. “Hot-spots” of localized anthropogenic inputs were observed in both subtropical systems but decreased rapidly both vertically and laterally in the sediments.

Inputs and fates of petroleum hydrocarbons in a subtropical marine estuary

Abstract Inputs and fates of petroleum from a higly urbanized area to a subtropical marine estuary were investigated by measuring hydrocarbon concentrations in municipal wastewater treatment plants, urban stormwater drains, sediments, and benthic organisms in and around Tampa Bay, FL. The concentrations of petroleum hydrocarbons discharged from secondary and tertiary treatment plants in this area were lower than concentrations previously reported for other treatment plants in temperate regions. Samples collected from urban storm drains under base flow conditions were also low. The generally low levels of petroleum hydrocarbons in the sediments and organisms throughout Tampa Bay suggest that the bay is relatively pristine with respect to petroleum hydrocarbon contamination. Since it is unlikely that the anthropogenic input of hydrocarbons to this estuary is significantly lower than in other urbanized areas, we suggest that elevated annual temperatures in this subtropical system result in increased metabolic rates of microorganisms and more rapid degradation or metabolism of the petroleum hydrocarbons.