Lees D.,Center for Environment
Food and Environmental Virology | Year: 2010
The viruses primarily associated with shellfish-borne illness are norovirus, causing gastroenteritis and hepatitis A virus (HAV). Recent years have seen a proliferation of publications on methods for detection of these viruses in shellfish using polymerase chain reaction (PCR). However, currently no standard harmonised procedures have been published. Standardisation is necessary before virus methods can be considered for adoption within a regulatory framework. A European standardisation working group is developing a two-part (quantitative and qualitative) standard method for virus detection in foodstuffs, including shellfish, which has the potential to be incorporated into EU legislation as a reference method. This article describes the development of the standard method and outlines the key methodology principles adopted, the controls and other quality assurance measures supporting the method and future necessary developments in the area. © 2010 Her Majesty the Queen.
Bolam S.G.,Center for Environment
Environmental Monitoring and Assessment | Year: 2011
In many coastal regions, the disposal of dredged material constitutes the largest (albeit often localised) anthropogenic disturbance to the seabed. Impacts can be minimised by reducing the amount of sediment overburden on the bed at any one time allowing short-term recovery to proceed via the vertical migration of resident species. However, there is currently a limited understanding of the ability of such species to successfully vertically migrate. This study presents the findings of a field experiment to investigate the vertical migratory capability of temperate macroinvertebrate species following the placement of simulated dredged material. The relationships between vertical migration success with sediment characteristics (organic carbon and sand content) and placement depth were explicitly examined. While the polychaete worms Tharyx sp. A. and Streblospio shrubsolii showed poor vertical migration with only 6 cm of sediment overburden, the oligochaete Tubif icoides benedii showed some recovery while the gastropod mollusc Hydrobiaulvae exhibited good migratory success, even with 16 cm of sediment overburden. While increases in sand content from 16% to 38% had no noticeable effect on vertical migration, increased sediment organic content from 0.8% to 3.3% detrimentally affected vertical migratory activity. The results support the theory that species' survival following sediment burial is trophic group-related. The relevance of these findings with respect to dredged material disposal management is discussed. © Springer Science+Business Media B.V. 2011.
Bolam S.G.,Center for Environment
Marine Environmental Research | Year: 2014
There is a growing need to understand the functional implications of anthropogenic pressures, such as those following coastal disposal of dredged material. Current assessments, based on taxonomic structure of benthic organisms, only provide a limited capacity to determine functional impacts or recovery. This study assesses recovery of two intertidal dredged material recharge schemes, comparing results obtained based on taxonomic structure (univariate and multivariate approaches) and function (biological trait composition, functional diversity, secondary production) of the benthic assemblages.The assemblages recolonising both schemes were consistently less speciose, less densely-populated and exhibited multivariate community structures that differed from those of the reference areas. However, for both schemes metrics of functionality converged to those of reference areas, although some differences in trait composition persisted for up to 3 years.These data support the proposition that impacts of, and recovery from, anthropogenic disturbance should be assessed using a combination of both functional and taxonomic structural approaches. © 2014.
Scott A.P.,Center for Environment
Steroids | Year: 2013
In assessing the evidence as to whether vertebrate sex steroids (e.g. testosterone, estradiol, progesterone) have hormonal actions in mollusks, ca. 85% of research papers report at least one biological effect; and 18 out of 21 review papers (published between 1970 and 2012) express a positive view. However, just under half of the research studies can be rejected on the grounds that they did not actually test steroids, but compounds or mixtures that were only presumed to behave as steroids (or modulators of steroids) on the basis of their effects in vertebrates (e.g. Bisphenol-A, nonylphenol and sewage treatment effluents). Of the remaining 55 papers, some can be criticized for having no statistical analysis; some for using only a single dose of steroid; others for having irregular dose-response curves; 40 out of the 55 for not replicating the treatments; and 50 out of 55 for having no within-study repetition. Furthermore, most studies had very low effect sizes in comparison to fish-based bioassays for steroids (i.e. they had a very weak 'signal-to-noise' ratio). When these facts are combined with the fact that none of the studies were conducted with rigorous randomization or 'blinding' procedures (implying the possibility of 'operator bias') one must conclude that there is no indisputable bioassay evidence that vertebrate sex steroids have endocrinological or reproductive roles in mollusks. The only observation that has been independently validated is the ability of estradiol to trigger rapid (1-5 min) lysosomal membrane breakdown in hemocytes of Mytilus spp. This is a typical 'inflammatory' response, however, and is not proof that estradiol is a hormone-especially when taken in conjunction with the evidence (discussed in a previous review) that mollusks have neither the enzymes necessary to synthesize vertebrate steroids nor nuclear receptors with which to respond to them. © 2012 Elsevier Inc. All rights reserved.
Schratzberger M.,Center for Environment
Marine Pollution Bulletin | Year: 2012
The need for scientific advice to manage the aquatic environment in an ecosystem context has never been greater. Many assessments of ecosystem state and change use inadequate data on non-conspicuous, non-target organisms. These include meiofauna, a diverse group of small-sized organisms (<1. mm) that live in a range of terrestrial and aquatic environments. Meiobenthic research published between 2007 and 2011 has failed to underpin ecosystem management and conservation practices. This is partly because of the belief amongst decision-makers and the public that microscopic organisms beyond our normal range of perception are ecologically unimportant. Methodological limitations related to the taxonomic identification of small-sized organisms and the narrow scope of many contemporary meiofauna studies are also to blame. This article explores ways in which meiobenthologists can improve the impact and uptake of their research. © 2012 .