Tuesday, 1 March 2011
Wildlife Suffers As Oil Spreads Along Spanish Coast
Second ship exploits disaster by washing out tanks. Fresh slicks of black, viscous oil continued to wash up on to the beaches of north-west Spain yesterday as the fuel left behind by the sunken tanker Prestige began to spread south down the coast.
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Marine iguanas hit by oil slick
The unique marine iguanas of the Galapagos islands have been devastated by the aftermath of an oil spill, scientists say, losing almost two thirds of their number on one island since a tanker ran aground in January last year.
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A chemical investigation of the transport and fate of petroleum hydrocarbons in littoral and benthic environments: The TSESIS oil spill
Received 6 February 1981.
Available online 26 March 2003.
Abstract
The fate of saturated and aromatic hydrocarbons discharged into the coastal Baltic Sea environment from the TSESIS oil spill has been studied in the acute and postacute (one year) phases of the spill. Periodic samples of Mytilus edulis (mussels) from eight littoral zone stations and Macoma balthica from nine soft bottom stations were obtained as well as sediment trap samples and surface sediment samples. Glass capillary gas chromatography and gas chromatographic mass spectrometry were used as the analytical tools to determine saturated and aromatic hydrocarbon composition and concentrations in these samples.
Sediment trap samples indicated that sizable quantities of chemically and microbially weathered oil were sedimented, and available for benthic uptake shortly after the spill. After initial uptake of sedimented oil (500 to 1000 μ/g dry weight), Macoma populations appear to have begun slow depuration through the first winter after the spill, but TSESIS oil was again introduced to the benthic stations studied during the following summer. Mytilus populations in the region were severely impacted by the oil. Initial depuration of spilled oil during the first month was rapid and nearly complete at all but the most heavily impacted stations one year after the spill. The post-spill depuration of assimilated hydrocarbons was characterised by a relative retention of alkylated dibenzothiophenes and alkylated phenanthrenes compared to their unsubstituted parent compounds and compared with the entire homologous naphthalene series.
These data suggest that petroleum hydrocarbons from the TSESIS spill have become a chronic source of degraded saturated and aromatic hydrocarbons to the soft bottom benthic communities. Petroleum hydrocarbons in the benthic environment from this spill appear to reside in the difficulty sampled and mobile flucculent layer at the sediment/water interface and may affect epifaunal communities for an extended period of time.
EFFECTS OF THE EXXON VALDEZ OIL SPILL ON MARINE BIRD COMMUNITIES IN PRINCE WILLIAM SOUND
Ecological Applications © 1996 Ecological Society of America
Abstract
The supertanker Exxon Valdez ran aground on 24 March 1989, spilling $41 \times 10^6$ L of oil into Prince William Sound, Alaska. To examine effects of this oil spill on the marine bird community, we analyzed data from 11 survey cruises between June 1989 and August 1991. Cruises were conducted in 10 study bays differing in the magnitude of initial oiling. We gauged bird responses to the spill in terms of habitat use, measured by frequency of bay occupancy and species abundances as functions of initial bay oiling. We focused on community-level measures to obtain a broader perspective than can be obtained from studies directed toward individual species of concern. Effects of the oil spill on community measures were most apparent shortly after the spill but diminished rapidly. Species richness was significantly lower in 1989 than at the same season 1-2 yr later, especially in heavily oiled bays. Species diversity (log-series $\alpha$) was also significantly reduced in more heavily oiled bays in early summer 1989 and 1990, but impacts evident in midsummer and fall 1989 were absent 1 yr later, and there were no significant relationships between diversity and bay oiling after midsummer 1990. Species occurrence in bays was more restricted immediately following the spill than 1-2 yr later, and widespread species were less abundant in early summer and fall 1989 than at the same seasons 1 yr later. This latter pattern was reversed in the midsummer surveys, perhaps because spill clean-up activities attracted large numbers of nonbreeding gulls. We used cluster analysis to define six avian guilds based on ecological characteristics of the species. Species richness of several guilds of birds feeding on or close to the shoreline was negatively related to initial oiling level until early or midsummer 1990, but not thereafter. Of these guilds, the richness of a guild of winter visitant and resident species showed the greatest negative association with initial oiling. However, the richness of guilds of solitary or colonial species that dive and/or feed on fish showed no significant relationships with oiling at any time. Correspondence analysis based on bird community composition indicated clear differences between heavily oiled and unoiled bays in 1989, but overall community composition converged between these sets of bays in subsequent years. Our analyses indicated that the Exxon Valdez oil spill had significant initial impacts on marine bird community structure, although they were not evenly distributed among ecological guilds. Even during the first survey, many species were present in the most heavily oiled bays. Although a few species continued to show spill impacts in late 1991, none of the community measures indicated continuing negative oiling effects. This suggests that, at the community level, recovery was well underway, consistent with observations that seabird habitat had apparently returned to normal in all but a few localized areas by mid-1991. Seabird communities appear to have considerable resiliency to such severe but relatively short-term perturbations, possibly because birds move over a regional scale. It may, therefore, be important to consider regional processes in
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