The effect of oil pollution on the reproduction and feeding behaviour of the sea anemone Actinia equina

The effects of oil pollution on the sea anemone Actinia equina were investigated. Chronic pollution with 2.5 ml.l^?1 crude oil resulted, for about seven weeks, in ejection of increased numbers of the young which are normally brooded within the gastric cavity. Subsequently the numbers of surviving young being produced fell to zero, and the ovaries were found to be regressed and lacking ova. The anemones were also more frequently observed with tentacles expanded and mouth open, but the response to food offered to the tentacles was slow or absent. In separate tests it was found that crude oil presented on filter paper to the anemones could act as a feeding inducer, but that it interfered with or diluted the action of natural feeding inducers present in fish muscle extract. These effects are comparable with those which oil pollution has been found by other workers to have upon other anthozoans—the corals.     

Effects of oil on water filtration by exposed sandy beaches

The most important natural function of exposed sandy beaches is the filtration of large volumes of sea water which are flushed through the interstitial pore system by the actions of tides and waves. In this process organic material is mineralized by the interstitial fauna and nutrients returned to the sea. This paper examines the physical effects of oil in blocking or reducing this filtration. Reduced filtration of sea water may be caused by prevention or retardation of interstitial water flow and/or decrease in pore space. The magnitude of the effects depends on the volume of oil, its state of weathering, its location on the beach and its degree of admixture with sand. It appears that under all but the heaviest conditions of pollution these effects are relatively small and only become significant in situ when discrete layers of weathered oil occur near the surface in the upper intertidal zone where maximum water input normally occurs.     

Impaired osmoregulation in the shrimp Palaemon adspersus exposed to crude oil extract

Palaemon adspersus is a hyper- and hypo-osmoregulating shallow-water shrimp. For a maximum period of 34 days P. adspersus were exposed to 20, 70, 100 and 200 ppb WSF of North Sea crude oil. The osmotic concentration of the haemolymph was measured by freezing point depression once a week. The ability to maintain hyper-osmolality was significantly decreased (p<0.05) after one, two and three weeks exposure to 200, 70 and 100 ppb, respectively. No effect was observed in 20 ppb. After an accidental exposure of shrimps to 24 h acute oil pollution, they were placed in pure sea water. The ability to maintain hyper-osmolality was reduced one week after the accidental oil exposure, but was regained within three weeks.     

Killing of marine larvae by diesel oil

Fourteen species (five phyla) of pelagic larvae, when exposed to 0.5% of No. 2 diesel oil in sea water, survived from 3 to 72 hours excepting the larvae of the echinoderm Crossaster which lived for 8 days.     

Dissolved/dispersed hydrocarbons,tarballs and the surface microlayer: Experiences from an IOC/UNEP Workshop in Bermuda,December, 1984

An intercomparison exercise was conducted at the Bermuda Biological Station for Research, Inc, Bermuda on 1–15 December 1984. It primarily involved the testing of the IOC Manual for monitoring oil and dissolved/dispersed petroleum hydrocarbons (DDPH) in marine waters and on beaches (IOC, Manuals and Guides, No. 13). An additional exercise sought to intercompare methodologies for the collection of sea surface microlayer samples.DDPH measurements in the inshore waters of Bermuda resulted in a mean concentration of 0.057 μg l⁻¹ of (n = 30) chrysene equivalents with a 60% relative standard deviation (RSD). Open ocean samples yielded a mean concentration of 0.011 μg l⁻¹ (n = 44) with a 65% RSD. These concentrations are extremely low and the results indicate that the method described in the Manual is sufficiently sensitive for the detection of ‘hot spots’The collection of beach tar using the method outlined in the Manual indicated that the data, when expresed as per metre of linear beach length, are an extremely good measure of oil contamination. The mean of 42 collections was 23.1 ± 14.4 g m⁻¹ in the first sampling period and the mean of 39 transects was 40.6 ± 17.7 g m⁻¹ on the second sampling period. Although 14 individuals took part in the sampling the results of individuals were consistent enough to demonstrate that beach tar collections are indeed valuable tools for monitoring contamination by petroleum in the marine environment.The operational manual for the sampling of the sea surface microlayer (IOC Manuals and Guides, No. 15), was also tested. The results indicated that this method collects reproduceable volumes of elevated concentrations of materials from the sea surface suitable at least for qualitative analyses. However, the spatial distribution and stability of surface films may render quantitative analyses less meaningful.     

The formulation of an effective demulsifier for oil spill emulsions

The formation of stable sea water-in-crude oil emulsions after an oil spill was first reported after the Torrey Canyon wreck in 1967. The problem of handling this stable water (65%)-in-oil (35%) emulsion rather than oil is evidenced in the additional expensive on-site storage requirement as well as the handling difficulty with the viscous semi-solid emulsion. This paper details the results of an R&D program that has established the mechanism for the formation of this emulsion. This insight enabled a specific effective chemical demulsifier to be formulated. A treatment technique was devised that entails injecting the demulsifier into the oil spill emulsion as it is skimmed from the water surface. The emulsion is then rapidly separated into water-free oil and a clean-water phase that can be decanted back into the sea. Full-scale tests were successfully conducted by JBF Scientific Corp. using two types of commercial JBF DIP skimmers in a small concrete lined pond.     

Analysis of community structure of a microbial consortium capable of degrading benzo(a)pyrene by DGGE

A microbial consortium was obtained by enrichment culture of sea water samples collected from Botan oil port in Xiamen, China, using the persistent high concentration of a mixture of polycyclic aromatic hydrocarbons enrichment strategy. Denaturing gradient gel electrophoresis (DGGE) was used to investigate the bacterial composition and community dynamic changes based on PCR amplification of 16S rRNA genes during batch culture enrichment. Using the spray-plate method, three bacteria, designated as BL01, BL02 and BL03, which corresponded to the dominant bands in the DGGE profiles, were isolated from the consortium. Sequence analysis showed that BL01, BL02 and BL03 were phylogenetically close to Ochrobactrum sp., Stenotrophomonas maltophilia and Pseudomonas fluorescens, respectively. The degradation of benzo(a)pyrene (BaP), a model high-molecular-weight polycyclic aromatic hydrocarbon (HMW PAH) compound was investigated using individual isolates, a mixture of the three isolates, and the microbial consortium (BL) originally isolated from the oil port sea water. Results showed that the order of degradative ability was BL > the mixture of the three isolates > individual isolates. BL degraded 44.07% of the 10 ppm BaP after 14 days incubation, which showed the highest capability for HMW PAH compound degradation.Our results revealed that this high selective pressure strategy was feasible and effective in enriching the HMW PAH-degraders from the original sea water samples.     

The Arctic is no longer put on ice: Evaluation of Polar cod (Boreogadussaida) as a monitoring species of oil pollution in cold waters

The withdrawing Arctic ice edge will facilitate future sea transport and exploration activities in the area, which calls for the establishment of relevant cold water monitoring species. The present study presents first results of field baseline levels for core oil pollution biomarkers in Polar cod (Boreogadussaida) sampled from pristine, Arctic waters. Furthermore, biomarker response levels were characterized in controlled laboratory exposure experiments running over 2 weeks. Fish exposed to a simulated petrogenic spill (1 ppm dispersed, crude oil) exhibited elevated hepatic EROD activity, bile PAH-metabolites, and hepatic DNA-adducts, whereas male individuals exposed to simulated produced water (30 ppb nonylphenol) exhibited a strong induction of plasma vitellogenin. In conclusion, the results demonstrated low and robust biomarker baseline levels that were clearly different from exposure responses. In combination with its high abundance and circumpolar distribution, the Polar cod seems well qualified for oil pollution monitoring in Arctic waters.     

Are sea otters being exposed to subsurface intertidal oil residues from the Exxon Valdez oil spill?

Twenty years after the Exxon Valdez oil spill, scattered patches of subsurface oil residues (SSOR) can still be found in intertidal sediments at a small number of shoreline locations in Prince William Sound, Alaska. Some scientists hypothesize that sea otters continue to be exposed to SSOR by direct contact when otters dig pits in search of clams. This hypothesis is examined through site-specific examinations where SSOR and otter-dug pits co-occur. Surveys documented the exact sediment characteristics and locations on the shore at the only three subdivisions where both SSOR and otter pits were found after 2000. Shoreline characteristics and tidal heights where SSOR have persisted are not suitable habitat for sea otters to dig pits during foraging. There is clear separation between areas containing SSOR and otter foraging pits. The evidence allows us to reject the hypothesis that sea otters encounter and are being exposed by direct contact to SSOR.     

Correlation of dispersant effectiveness and toxicity of oil dispersants towards the alga Chlamydomonas reinhardti

Using synchronous cultures of the unicellular green alga Chlamydomonas reinhardti, the toxicities of mixtures of Ekofisk crude oil and oil dispersants were measured. Sixteen so-called concentrates and 10 solvent-based dispersants were tested. The dispersing effectiveness of these compounds with respect to the Ekofisk crude oil was also measured. The concentrates were tested undiluted as well as diluted using algal growth medium (2‰ salinity) and artificial sea water (33‰ salinity) as dispersing liquid. The solvent-based compounds were tested in algal medium. For all compounds we found significant correlations between their toxicity and their effectiveness in dispersing the Ekofisk oil, such that the more effective the compound, the more toxic it was.     

Role of glacial Arctic Ocean ice sheets in Pleistocene oxygen isotope and sea level records

A comparison of the oxygen isotope signal in deep-sea benthic foraminifera with the record of glacio-eustatic sea level for the last 160,000 years reveals that the amplitude of the benthic δ¹⁸O records predicts more continental ice volume than appears to be reflected in lowered sea level stands. These differences between the benthic δ¹⁸O ice volume estimates and radiometrically-dated records of eustatic sea level are consistent with the presence of a large floating Arctic Ocean ice mass during glacial intervals. The presence of an Arctic Ocean ice sheet during glacial intervals may account for the two climatic modes observed in oxygen isotope records which span the entire Pleistocene. The early Pleistocene (1.8 to 0.9 Myr B.P.) interval is characterized by low-amplitude, high-frequency δ¹⁸O fluctuations between glacial and interglacial periods, while the late Pleistocene (0.9 Myr B.P. to present) is characterized by large-amplitude, low-frequency δ¹⁸O changes. These two climatic modes can be explained by the initiation of earth orbital conditions favoring the co-occurrence of glacial period Arctic Ocean ice sheets and large continental ice sheets approximately 900,000 years before present.     

PCB exposure in sea otters and harlequin ducks in relation to history of contamination by the Exxon Valdez oil spill

Exposure to contaminants other than petroleum hydrocarbons could confound interpretation of Exxon Valdez oil spill effects on biota at Prince William Sound, Alaska. Hence, we investigated polychlorinated biphenyls (PCBs) in blood of sea otters and harlequin ducks sampled during 1998. PCB concentrations characterized by lower chlorinated congeners were highest in sea otters from the unoiled area, whereas concentrations were similar among harlequin ducks from the oiled and unoiled area. Blood enzymes often elevated by xenobiotics were not related to PCB concentrations in sea otters. Only sea otters from the unoiled area had estimated risk from PCBs, and PCB composition or concentrations did not correspond to reported lower measures of population performance in sea otters or harlequin ducks from the oiled area. PCBs probably did not influence limited sea otter or harlequin duck recovery in the oiled area a decade after the spill.     

On recording sea surface elevation with accelerometer buoys: lessons from ITOP (2010)

Measurements of significant wave height are made routinely throughout the world’s oceans, but a record of the sea surface elevation (η) is rarely kept. This is mostly due to memory limitations on data, but also, it is thought that buoy measurements of sea surface elevation are not as accurate as wave gauges mounted on stationary platforms. Accurate records of η which contain rogue waves (defined here as an individual wave at least twice the significant wave height) are of great interest to scientists and engineers. Using field data, procedures for tilt correcting and double integrating accelerometer data to produce a consistent record of η are given in this study. The data in this study are from experimental buoys deployed in the recent Impact of Typhoons on the Ocean in the Pacific (ITOP) field experiment which occurred in 2010. The statistics from the ITOP buoys is under that predicted by Rayleigh theory, but matches the distributions of Boccotti and others (Tayfun and Fedele) (Ocean Eng 34:1631-1649, 2007). Rogue waves were recorded throughout the experiment under various sea state conditions. Recommendations, as a result of lessons learned during ITOP, are made for the routine recording of η which may not add significantly to the existing data burden. The hope is that we might one day collect a worldwide database of rogue waves from the existing buoy network, which would progress our understanding of the rogue wave phenomenon and make work at sea safer.     

Disruption of Sema3A expression causes abnormal neural projection in heavy oil exposed Japanese flounder larvae

It has been well known that oil spills cause serious problems in the aquatic organisms. In particular, some species of teleosts, which develop on the sea surface thought to be affected by heavy oil (HO). During the embryogenesis, the nervous system is constructed. Therefore, it is important to study the toxicological effects of HO on the developing neurons. We exposed HO to eggs of Japanese flounder (Paralichthys olivaceus) and investigated the neural disorder. In larvae exposed by HO at the concentration of 8.75 mg/L, the facial and lateral line nerves partially entered into the incorrect region and the bundle was defasciculated. Furthermore, in the HO-exposed larvae, Sema3A, a kind of axon guidance molecule, was broadly expressed in second pharyngeal arch, a target region of facial nerve. Taken together, we suggested the possibility that the abnormal expression of Sema3A affected by HO exposure causes disruption of facial nerve scaffolding.     

Acute toxicity of inorganic mercury to Capitella

The polychaete worm Capitella capitata is shown to be fairly resistant to high concentrations of inorganic mercury. Survival of adults compared with those of the polychaete Ophryotrocha labronica shows that C. capitata can withstand 1 ppm Hg²⁺ for several days whilst O. labronica succombs to 0.5 ppm Hg²⁺ in 2 h.     

Increase of litter at the Arctic deep-sea observatory HAUSGARTEN

Although recent research has shown that marine litter has made it even to the remotest parts of our planet, little information is available about temporal trends on the deep ocean floor. To quantify litter on the deep seafloor over time, we analysed images from the HAUSGARTEN observatory (79°N) taken in 2002, 2004, 2007, 2008 and 2011 (2500 m depth). Our results indicate that litter increased from 3635 to 7710 items km⁻² between 2002 and 2011 and reached densities similar to those reported from a canyon near the Portuguese capital Lisboa. Plastic constituted the majority of litter (59%) followed by a black fabric (11%) and cardboard/paper (7%). Sixty-seven percent of the litter was entangled or colonised by invertebrates such as sponges (41%) or sea anemones (15%). The changes in litter could be an indirect consequence of the receding sea ice, which opens the Arctic Ocean to the impacts of man’s activities.     

Marine debris ingestion by coastal dolphins: What drives differences between sympatric species?

This study compared marine debris ingestion of the coastal dolphins Pontoporia blainvillei and Sotalia guianensis in a sympatric area in Atlantic Ocean. Among the 89 stomach contents samples of P. blainvillei, 14 (15.7%) contained marine debris. For S. guianensis, 77 stomach contents samples were analyzed and only one of which (1.30%) contained marine debris. The debris recovered was plastic material: nylon yarns and flexible plastics. Differences in feeding habits between the coastal dolphins were found to drive their differences regarding marine debris ingestion. The feeding activity of P. blainvillei is mainly near the sea bottom, which increases its chances of ingesting debris deposited on the seabed. In contrast, S. guianensis has a near-surface feeding habit. In the study area, the seabed is the main zone of accumulation of debris, and species with some degree of association with the sea bottom may be local bioindicators of marine debris pollution.     

The Urquiola oil spill,La Coruña,Spain: Case history and discussion of methods of control and clean-up

A massive oil spill affected approximately 215 km of coastline as a result of the grounding and subsequent explosion of the supertanker Urquiola at the entrance to the harbour at La Coruña, Spain, on 12 May 1976. A total of 99–100 000 tons of Persian Gulf crude oil was lost, most of which burned, but an estimated 25–30 000 tons washed ashore. Over 2000 tons of dispersants were applied to the oil at sea. Land-based clean-up and control methods were largely inadequate to combat the spread of oil, and were ineffective at preventing large scale environmental damage.     

Phase distribution of hydrocarbons in the water column after a pelagic deep ocean oil spill

Spills from wrecks are a potential major source of pollution in the deep ocean. However, not much is known about the fate of a spill at several kilometers depth, beyond the oceans continental shelves. Here, we report the phase distribution of hydrocarbons released from the wrecks of the Prestige tanker, several years after it sank in November 2002 to depths between 3500 and 3800 m. The released oil reached the surface waters above the wrecks without any signs of weathering and leaving an homogenous signature throughout the water column. At depths of several kilometers below the sea surface, the occurrence and spread of the deep sea oil spill could be evaluated better by quantifying and characterizing the dissolved hydrocarbon signature, rather than just the investigation of hydrocarbons in the suspended particulate matter.