Paul F. Kingston

Long-term Environmental Impact of Oil Spills

Abstract Oil contamination may persist in the marine environment for many years after an oil spill and, in exceptional cases such as salt marshes and mangrove swamps, the effects may be measurable for decades after the event. However, in most cases, environmental recovery is relatively swift and is complete within 2–10 years. Where oil has been eliminated from the scene, the long-term environmental impacts are generally confined to community structure anomalies that persist because of the longevity of the component species.

The impact of the Braer oil spill on the macrobenthic infauna of the sediments off the Shetland Islands

Following the wreck of the oil tanker Braer, a study of the benthic fauna in areas of sea-bed contaminated by oil was carried out. The results showed that no significant changes in benthic community structure, as characterized by species richness, individual abundance and diversity could be related to the areas of sea-bed affected by the Braer oil spill. The major factors determining the distribution of species in the affected areas appeared to be primarily related to the nature of the sediments, and not the degree of oil contamination. However, the levels of petroleum hydrocarbons in the most heavily contaminated sediments were sufficiently high to have eliminated sensitive groups such as the Amphipoda and encourage species associated with oil pollution, but the overall numbers of species involved and their abundances were too small to significantly affect community structure. There is no evidence from the analysis of species abundance distributions that mass mortality of the benthos took place at any time after the Braer oil spill, although there are indications that a few species may have been eliminated and were recruiting at the time of the survey. The lack of evidence of major impact from the spill indicates that either the Braer oil was of such low toxicity as to not significantly disrupt benthic community structure, or that the sampling programme was carried out too soon after the spill to enable the full effects of its impact to be detected.

Observations on the effects of barite on the gill tissues of the suspension feeder Cerastoderma edule (Linné) and the deposit feeder Macoma balthica (Linné).

Barite, an important component of offshore drilling muds, is shown to adversely affect the ctenidia of the suspension feeding bivalve, Cerastoderma edule and the deposit feeder, Macoma balthica. SEM observations showed that exposure to barite caused cilia to shorten and coagulate, and, in some extreme cases, cause the disintegration of the gill structure itself. Using a simple ciliary condition index (CCI) the impact of the barite was quantified and damage rates expressed. The bivalves were treated with daily doses of 1, 2, and 3-mm depth equivalents of barite. In all treatments significant damage to the gills was recorded although, in the case of the 1-mm dose rate, this did not occur for 4 days. In the other two treatments, damage was apparent within a day of exposure with 100% mortality occurring within 12 days. Macoma balthica appeared slightly more tolerant of exposure to barite than C. edule.

The sublittoral benthic fauna of the estuary and Firth of Forth, Scotland

The structure of the sublittoral benthic macro-invertebrate populations of the Forth estuary and firth, Scotland, is described, giving the species richness, abundance and biomass for the area from the freshwater tidal limit to the North Sea boundary. Eight faunal associations have been defined, which include classical Petersen communities in the marine area and transition associations within the estuary. The spatial distributions of the associations are predominantly the result of the physical environment, but superimposed on the effects of salinity, sediment type and bathymetry are the effects of urbanisation, industrialisation, dredging and spoil disposal and thermal discharges. The benthos of the major part of the firth has been little affected, although that of the peripheral and estuarine areas does show anthropogenic effects. The water column-benthos and fisheries-benthos interactions are also discussed. Elevated levels of nutrients in the water column may be the cause of enriched benthic populations in the firth and an assessment of the fish-benthos coupling indicates an estuarine functioning similar to other northwestern European areas.

Data integration for European marine biodiversity research: creating a database on benthos and plankton to study large-scale patterns and long-term changes.

The general aim of setting up a central database on benthos and plankton was to integrate long-, medium- and short-term datasets on marine biodiversity. Such a database makes it possible to analyse species assemblages and their changes on spatial and temporal scales across Europe. Data collation lasted from early 2007 until August 2008, during which 67 datasets were collected covering three divergent habitats (rocky shores, soft bottoms and the pelagic environment). The database contains a total of 4,525 distinct taxa, 17,117 unique sampling locations and over 45,500 collected samples, representing almost 542,000 distribution records. The database geographically covers the North Sea (221,452 distribution records), the North-East Atlantic (98,796 distribution records) and furthermore the Baltic Sea, the Arctic and the Mediterranean. Data from 1858 to 2008 are presented in the database, with the longest time-series from the Baltic Sea soft bottom benthos. Each delivered dataset was subjected to certain quality control procedures, especially on the level of taxonomy. The standardisation procedure enables pan-European analyses without the hazard of taxonomic artefacts resulting from different determination skills. A case study on rocky shore and pelagic data in different geographical regions shows a general overestimation of biodiversity when making use of data before quality control compared to the same estimations after quality control. These results prove that the contribution of a misspelled name or the use of an obsolete synonym is comparable to the introduction of a rare species, having adverse effects on further diversity calculations. The quality checked data source is now ready to test geographical and temporal hypotheses on a large scale.

Oil contamination of sedimentary shores of the Galápagos islands following the wreck of the Jessica

Sediment samples were collected from sandy beaches at a variety of sites in the southern Galápagos Archipelago to assess levels of hydrocarbon contamination following the wreck of the oil tanker Jessica. Hydrocarbon levels in sediments were generally very low by international standards ranging between 0.4 and 48.9 ppm, with contamination attributable to the Jessica only detected at three sites Santa Fe, Playa Estación (Puerto Ayora, Santa Cruz) and Long Beach (Isabela). There was evidence of residual hydrocarbon contamination from sources other than the wreck of the Jessica.

Octobranchus floriceps sp. nov. (Polychaeta: Trichobranchidae) from the northern North Sea with a reexamination of O. antarcticus Monro

Abstract Octobranchus floriceps sp. nov., the first record of the genus Octobranchus Marion & Bobretzky, 1875 in northern European waters, is described from between 145 and 370 m depth. Following re-examination of Octobranchus antarcticus Monro, 1936, and a proposal that the genus Novobranchus Berkeley & Berkeley, 1954, be considered a synonym of Octobranchus, the characteristics of all 6 members of the genus are discussed. O. floriceps appears most closely related to 0. antarcticus.