Partitioning of metals in the tissues and cytosolic fraction of Cerastoderma edule.

The concentrations of Cd, Cu and Zn have been determined in the tissues and the cytosolic fraction of the common cockle, Cerastoderma edule, collected from sediments in the Tamar, Plym and Avon estuaries (South West, England). Metal concentrations in the tissues of C. edule from the Avon were lower than those from the Tamar and Plym, except for Cu in the digestive gland. Significant statistical relationships were only obtained between the total sedimentary metal concentrations and Cd in the body of C. edule and Cu in the digestive gland. The cytosolic fraction was extracted from each of the tissues and separated for protein analysis thereby allowing determination of the metal contents in high molecular weight (HMW) compounds, metallothionein-like proteins (MTLP) and very low molecular weight (VLMW) compounds. The digestive glands of C. edule from the Avon had relatively low concentrations of MTLP, whereas MTLP concentrations in the digestive gland of cockles from the Tamar and Plym were higher. The cytosolic fraction of C. edule had relatively low total Cd and Cu concentrations associated with MTLP, whereas Zn was preferentially associated with the HMW and the VLMW components. The results are relevant to metal distributions in C. edule and the role of cytosols in the management of metals by C. edule and other invertebrates.

Pleistocene expansion, anthropogenic pressure and ocean currents: Disentangling the past and ongoing evolutionary history of Patella aspera Röding, 1798 in the archipelago of Madeira.

AIMS: Rising sea-level following the Last Glacial Maximum lead to fragmentation of coastal limpet populations between islands of the Archipelago of Madeira. This fragmentation is reinforced by recent heavy exploitation reducing effective population size on Madeira Island. We use the limpet P. aspera to understand how the role of processes at different time scales (i.e. changes in the sea level and overexploitation) can influence the genetic composition of an extant species, relating these processes to reproductive phenology and seasonal shifts in ocean currents. LOCATION: Madeira Island, Porto Santo and Desertas (Archipelago of Madeira, NE Atlantic Ocean). TAXON: The limpet Patella aspera. METHODS: Twelve microsatellite genetic markers were used. A power analysis was used to evaluate the power of the microsatellite markers to detect a signal of population differentiation. Long-term past migrations were assessed using a Bayesian Markov Montecarlo approach in the software MIGRATE-n to estimate mutation-scaled migration rates (M = m/µ; m, probability of a lineage immigrating per generation; µ, mutation rate). Two scenarios were evaluated using an Approximate Bayesian Computation (ABC) in the software DIYABC 2.1 (i) Scenario 1: considered a population scenario from a reduced Ne at time t3 to a higher Ne at time t2; and (ii) Scenario 2 considering a reduction of Ne from a time t3 to a time t2. RESULTS: Colonization of the archipelago by Portuguese settlers six centuries ago probably led to an important decrease in the genetic diversity of the species (Ne). Contemporary gene flow strongly support a pattern of high asymmetric connectivity explained by the reproductive phenology of the species and spatio-temporal seasonal changes in the ocean currents. Spatio-temporal reconstructions using Bayesian methods, including coalescent and Approximate Bayesian Computation (ABC) approaches, suggest changes in the migration patterns from highly symmetric to highly asymmetric connectivity with subtle population differentiation as consequence of post-glacial maximum sea level rise during the Holocene. MAIN CONCLUSIONS: Our results suggest that anthropogenic activity could have had serious effects on the genetic diversity of heavily exploited littoral species since the end of the Pleistocene, probably accelerating in recent years.

Recovery of an urbanised estuary: Clean-up, de-industrialisation and restoration of redundant dock-basins in the Mersey.

For much of the 20th century, the Mersey in North West England was one of the worst polluted estuaries in Europe. Water from a range of polluting industries plus domestic sewage was discharged into the Mersey Catchment and Estuary. Recovery came through a concerted clean-up campaign and tightening environmental regulations, partly driven by European Commission Directives, coupled with de-industrialisation from the 1970s onward. Recovery of oxygen levels in the Estuary led to the return of a productive ecosystem. This led to conservation designations, but also concerns about transfer of pollutants to higher trophic levels in fish, birds and humans. As part of urban renewal, ecosystems in disused dock basins were restored using mussel biofiltration and artificial de-stratification, facilitating commercial redevelopment and creation of a tourist destination. The degradation and recovery of the Mersey from peak-pollution in the mid-20th century is put in the context of wider environmental change and briefly compared to other systems to develop a hysteresis model of degradation and recovery, often to novel ecosystems.

Distinguishing globally-driven changes from regional- and local-scale impacts: The case for long-term and broad-scale studies of recovery from pollution.

Marine ecosystems are subject to anthropogenic change at global, regional and local scales. Global drivers interact with regional- and local-scale impacts of both a chronic and acute nature. Natural fluctuations and those driven by climate change need to be understood to diagnose local- and regional-scale impacts, and to inform assessments of recovery. Three case studies are used to illustrate the need for long-term studies: (i) separation of the influence of fishing pressure from climate change on bottom fish in the English Channel; (ii) recovery of rocky shore assemblages from the Torrey Canyon oil spill in the southwest of England; (iii) interaction of climate change and chronic Tributyltin pollution affecting recovery of rocky shore populations following the Torrey Canyon oil spill. We emphasize that "baselines" or "reference states" are better viewed as envelopes that are dependent on the time window of observation. Recommendations are made for adaptive management in a rapidly changing world.

The role of sustained observations in tracking impacts of environmental change on marine biodiversity and ecosystems.

Marine biodiversity currently faces unprecedented threats from multiple pressures arising from human activities. Global drivers such as climate change and ocean acidification interact with regional eutrophication, exploitation of commercial fish stocks and localized pressures including pollution, coastal development and the extraction of aggregates and fuel, causing alteration and degradation of habitats and communities. Segregating natural from anthropogenically induced change in marine ecosystems requires long-term, sustained observations of marine biota. In this review, we outline the history of biological recording in the coastal and shelf seas of the UK and Ireland and highlight where sustained observations have contributed new understanding of how anthropogenic activities have impacted on marine biodiversity. The contributions of sustained observations, from those collected at observatories, single station platforms and multiple-site programmes to the emergent field of multiple stressor impacts research, are discussed, along with implications for management and sustainable governance of marine resources in an era of unprecedented use of the marine environment.

New polymorphic microsatellite markers for the limpet Patella rustica and cross-priming testing in four Patella species.

Eighteen microsatellite markers have been characterized from the Patella rustica genome. An average of 10 alleles per locus and an expected heterozygosity ranging from 0.054 to 0.937 were observed in a sample of 32 wild individuals from Viana do Castelo, Portugal. Distinct cross-priming amplification rates were recovered on four additional Patella species. Three monomorphic P. rustica loci were polymorphic in other Patella species. The microsatellites developed herein could be a useful intraspecific genetic tool to undertake fine population studies in the genus Patella.

Diagnostic monitoring of a changing environment: an alternative UK perspective.

Adaptive management of the marine environment requires an understanding of the complex interactions within it. Establishing levels of natural variability within and between marine ecosystems is a necessary prerequisite to this process and requires a monitoring programme which takes account of the issues of time, space and scale. In this paper, we argue that an ecosystem approach to managing the marine environment should take direct account of climate change indicators at a regional level if it is to cope with the unprecedented change expected as a result of human impacts on the earth climate system. We discuss the purpose of environmental monitoring and the importance of maintaining long-term time series. Recommendations are made on the use of these data in conjunction with modern extrapolation and integration tools (e.g. ecosystem models, remote sensing) to provide a diagnostic approach to the management of marine ecosystems, based on adaptive indicators and dynamic baselines.

Development of an electrochemical assay for 2,6-dinitrotoluene, based on a screen-printed carbon electrode, and its potential application in bioanalysis, occupational and public health.

Screen-printed carbon electrodes (SPCEs) have been successfully exploited as disposable sensors for the measurement of 2,6-dinitrotoluene (2,6-DNT) using a stripping voltammetric method. Initial investigations were undertaken using cyclic voltammetry (CV) to characterise the redox behaviour at the SPCEs. Further studies were then performed to deduce the optimum applied potential and accumulation time for the stripping voltammetric procedure. In addition, a study was carried out to ascertain whether small volumes of samples could be reliably used for analysis. From these studies it was shown that a 100 microl aliquot of sample could be analysed and the calibration plot was linear from 161 ng ml(-1) to 137 microg ml(-1) (R(2)=0.9991), the former concentration being the detection limit. The effects of the major components of human saliva at concentrations normally present were investigated. Of the individual components tested, only Cl(-) and albumen were found to interfere. The presence of the latter could be easily overcome by the addition of (NH(4))(2)SO(4). An interference study was also carried out on some inorganic and organic species that may be present in water samples. The sensors were evaluated by carrying out 2,6-DNT determinations on spiked and unspiked human saliva, dust wipe and potable water samples. Mean recoveries of 47.5, 73.4 and 102.4% were obtained; coefficients of variation of 7.88, 6.63 and 6.42% were calculated for a concentration of 9.1 microg ml(-1) in water, 10.6 microg ml(-1) saliva samples, and 141.1 ng cm(-2) for dust wipe samples, respectively. The performance characteristics show that the method holds promise and reliable data may be obtained for 2,6-DNT in bioanalysis and public health.

Recovery of polluted ecosystems: the case for long-term studies.

Recovery of marine ecosystems from pollution has tended to receive less attention than the study of new or continuing impacts, but such studies are important in charting recovery from acute incidents and following legislation to deal with chronic contamination. Recovery is inevitably a long-term process, and where such studies have been made they are often too short-lived. Interest quickly wanes following an acute incident and governmental bodies rapidly switch to new legislative priorities for chronic inputs. We review three case studies: recovery of dogwhelk populations after local extinction by tributyl tin leachates from anti-fouling paints; recovery of rocky shore communities from oil spills; and recovery of estuarine ecosystems from industrial and urban development. We then make some generalisations about recovery processes before making a plea for long-term studies of polluted areas.

Timing of squid migration reflects North Atlantic climate variability.

The environmental and biotic conditions affecting fisheries for cephalopods are only partially understood. A problem central to this is how climate change may influence population movements by altering the availability of thermal resources. In this study we investigate the links between climate and sea-temperature changes and squid arrival time off southwestern England over a 20-year period. We show that veined squid (Loligo forbesi) migrate eastward in the English Channel earlier when water in the preceding months is warmer, and that higher temperatures and early arrival correspond with warm (positive) phases of the North Atlantic oscillation (NAO). The timing of squid peak abundance advanced by 120-150 days in the warmest years ('early' years) compared with the coldest ('late' years). Furthermore, sea-bottom temperature was closely linked to the extent of squid movement. Temperature increases over the five months prior to and during the month of peak squid abundance did not differ between early and late years, indicating squid responded to temperature changes independently of time of year. We conclude that the temporal variation in peak abundance of squid seen off Plymouth represents temperature-dependent movement, which is in turn mediated by climatic changes associated with the NAO. Such climate-mediated movement may be a widespread characteristic of cephalopod populations worldwide, and may have implications for future fisheries management because global warming may alter both the timing and location of peak population abundance.

Clinical and laboratory effects of nifedipine in Raynaud's phenomenon.

The calcium channel blocking drug nifedipine was shown to be more effective than placebo as a treatment for Raynaud's phenomenon. Given in a dose of 10 mg four times a day it was well tolerated and reduced both the frequency and the severity of vasospastic attacks. There was, however, a large individual variation in response and while approximately half the patients showed marked improvement others showed no improvement at all. Patients with idiopathic Raynaud's phenomenon responded more favourably than those with systemic sclerosis. Nifedipine was shown to inhibit mitogen-induced lymphocyte proliferation but only in patients who responded to the drug clinically. Calcium channel blocking drugs may therefore have potential as immunoregulatory agents.

Limited joint mobility in diabetes mellitus.

The relationship of limited joint mobility and finger joint contractures in diabetics to age of onset, duration, and control of diabetes has not been established. We measured the mobility of metacarpophalangeal, wrist, elbow, and ankle joints and assessed the prevalence of finger joint contractures in 254 young diabetics and 110 controls. The presence of microvascular disease was assessed by ophthalmoscopy and urine analysis for proteinuria. An estimate of long-term diabetic control was obtained from a postal questionnaire. A generalised reduction in joint mobility was present in diabetics of all ages two years after diagnosis. The reduction in joint mobility in controls between the ages of 12 and 13 was exaggerated in the diabetics. Diabetics diagnosed before puberty were more severely affected than those with a postpubertal onset, independent of duration of diabetes. Finger joint contractures were a significant feature of longstanding diabetics (nine years or more duration) only.

Putative sense organs on the pallial tentacles of the limpet, Patella vulgata (L.).

The structure and ultrastructure of ciliary tufts on the pallial tentacles of the limpet Patella vulgata (L.) are described. The tip of each tentacle is covered by a dense crown of tufts and additional tufts can be seen scattered evenly across the surface of each tentacle. The cilia are nonmotile and nerve fibres run from the base of the ciliated cells suggesting a sensory function. Comparisons are made with ciliary tufts found in a Pacific species of limpet, Acmaea scutum, and other molluscan sensory structures.