A typology of North Sea oil and gas platforms.

Since the commercial exploitation of marine oil and gas reserves began in the middle of the twentieth century, extensive networks of offshore infrastructure have been installed globally. Many of the structures are now nearing the end of their operational lives and will soon require decommissioning, generating renewed interest in their environmental impacts and in the ecological consequences of their removal. However, such work requires selection of a subsample of assets for surveying; censuses of the entire 'population' in any given jurisdiction are practically impossible due to their sheer number. It is important, therefore, that the selected sample is sufficiently representative of the population to draw generalized conclusions. Here, a formal clustering methodology, partitioning around medoids, was used to produce a typology of surface-piercing oil and gas platforms in the North Sea. The variables used for clustering were hydrocarbon product, operational state, platform design and material, and substructure weight. Assessing intra-cluster variability identified 13 clusters as the optimum number. The most important distinguishing variable was platform type, isolating floating platforms first, then concrete gravity-based and then fixed steel. Following clustering, a geographic trend was evident, with oil production more prevalent in the north and gas in the south. The typology allows a representative subset of North Sea oil and gas platforms to be selected when designing a survey, or an assessment of the representativeness of a previously selected subset of platforms. This will facilitate the efficient use of the limited funding available for such studies.

Impact of ocean warming on sustainable fisheries management informs the Ecosystem Approach to Fisheries.

An integrated ecosystem model including fishing and the impact of rising temperatures, relative to species' thermal ranges, was used to assess the cumulative effect of future climate change and sustainable levels of fishing pressure on selected target species. Historically, important stocks of cod and whiting showed declining trends caused by high fisheries exploitation and strong top-down control by their main predators (grey seals and saithe). In a no-change climate scenario these stocks recovered under sustainable management scenarios due to the cumulative effect of reduced fishing and predation mortalities cascading through the food-web. However, rising temperature jeopardised boreal stenothermal species: causing severe declines in grey seals, cod, herring and haddock, while eurythermal species were not affected. The positive effect of a higher optimum temperature for whiting, in parallel with declines of its predators such as seals and cod, resulted in a strong increase for this stock under rising temperature scenarios, indicating a possible change in the contribution of stocks to the overall catch by the end of the century. These results highlight the importance of including environmental change in the ecosystem approach to achieve sustainable fisheries management.

Rosuvastatin promotes benefits on induced periodontitis in hypertensive rats.

BACKGROUND AND OBJECTIVE: The potential benefits of statins in modulating periodontal disease is supported by in vitro and clinical studies showing statins can induce a lower expression of proinflammatory cytokines and matrix metalloproteinases. The aim of this study was to evaluate the effects of rosuvastatin (ST) on ligature-induced periodontitis in spontaneously hypertensive rats (SHR). MATERIAL AND METHODS: Fifty-four adult male rats were divided into three groups: SHR-C, SHR-L and SHR-L-ST (C, control; L, ligature groups). In the SHR-L-ST group, animals were treated with daily 2 mg/kg ST administration. In L groups, a ligature remained around mandibular first molars for 10 d. Each group was divided for killing at 10 or 21 d postoperatively. Microtomographic and histometric analyses were performed. Osteoclastogenesis was evaluated by tartrate-resistant acid phosphatase assay and gene expression of 84 proinflammatory mediators by polymerase chain reaction array. RESULTS: The SHR-L-ST group showed reduced bone loss and attachment loss in comparison with the SHR-L group at both 10 and 21 d postoperatively (p < 0.05). ST decreased the amount of tartrate-resistant acid phosphatase-positive cells compared with the SHR-L group at both 10 and 21 d (p < 0.05). The SHR-L-ST group presented 14 genes differentially expressed when compared with SHR-L group, featuring a downregulated gene profile at 10 d. CONCLUSION: Statin therapy may promote a protective effect against alveolar bone and connective tissue attachment losses attributable to periodontitis in hypertensive rats through inflammatory gene profile modulation.

A visual survey technique for deep-water fishes: estimating anglerfish Lophius spp. abundance in closed areas.

A visual survey technique was employed to estimate the abundance and distribution of anglerfish Lophius spp. in areas where destructive sampling methods, such as trawling, are unacceptable. To enable visual surveying at depths of over 300 m, a deep towed vehicle was developed equipped with video, lights and other sensors and was towed at speeds of up to 1·5 m s⁻¹ and altitudes of up to 10 m (from the seabed) to survey large areas of the seabed around the Rockall Bank in the north-west Atlantic Ocean. The system allowed for areas up to 125 000 m² to be surveyed, a substantial area comparable to that surveyed by demersal-trawl sampling. Lophius spp. densities ranged from 15 to 736 fish km⁻²; these are comparable to estimated Lophius spp. densities determined by trawl surveys in adjacent areas. Estimates of Lophius spp. abundance in the closed areas ranged between 99,855 and 176,887 for the time series considered (2007-2011).

Depth-dependent swimbladder compression in herring Clupea harengus observed using magnetic resonance imaging.

Changes in swimbladder morphology in an Atlantic herring Clupea harengus with pressure were examined by magnetic resonance imaging of a dead fish in a purpose-built pressure chamber. Swimbladder volume changed with pressure according to Boyle's Law, but compression in the lateral aspect was greater than in the dorsal aspect. This uneven compression has a reduced effect on acoustic backscattering than symmetrical compression and would elicit less pronounced effects of depth on acoustic biomass estimates of C. harengus.