Intersex in the clam Scrobicularia plana: a sign of endocrine disruption in estuaries?

The phenomenon of endocrine disruption is currently a source of growing concern. Feminization of male fish in UK rivers has been shown to occur extensively and has been linked with exposure to endocrine-disrupting compounds present in the environment. Much less is known of the extent and scale of endocrine disruption in estuarine and marine ecosystems, particularly in invertebrates. We present evidence that intersex, in the form of ovotestis, is occurring in the common estuarine bivalve Scrobicularia plana, which is considered to be inherently gonochoristic. We report varying degrees in the severity of ovotestis in male S. plana, and have adopted and developed a grading method to assess the extent of this intersex condition. These findings indicate that S. plana offers potential for widespread screening and investigation of endocrine disruption, helping to focus remediatory strategy

Partitioning, bioavailability and effects of oestrogens and xenoestrogens in the aquatic environment

This review provides insights into the distribution and impact of oestrogens and xeno-oestrogens in the aquatic environment and highlights some significant knowledge gaps in our understanding of endocrine disrupting chemicals. Key areas of uncertainty in the assessment of risk include the role of estuarine sediments in mediating the fate and bioavailability of environmental (xeno)oestrogens (notably their transfer to benthic organisms and estuarine food chains), together with evidence for endocrine disruption in invertebrate populations. Emphasis is placed on using published information to interpret the behaviour and effects of a small number of ‘model compounds’ thought to contribute to oestrogenic effects in nature; namely, the natural steroid 17β-oestradiol (E2) and the synthetic hormone 17α-ethinyloestradiol (EE2), together with the alkylphenols octyl- and nonyl-phenol (OP, NP) as oestrogen mimics. Individual sections of the review are devoted to sources and concentrations of (xeno)oestrogens in waterways, sediment partitioning and persistence, bioaccumulation rates and routes, assays and biomarkers of oestrogenicity, and, finally, a synopsis of reproductive and ecological effects in aquatic species

Characterisation of the European Marine Sites in South West England: The Fal and Helford Candidate Special Area of Conservation (cSAC)

The Conservation (Natural Habitats, & c.) Regulations 1994 which implement the Habitats Directive (Council Directive 92/43/EEC) and Birds Directive (79/409/EEC) in the UK include a number of provisions for the protection of European Marine Sites (marine candidate Special Areas of Conservation (cSAC) and Special Protection Areas (SPAs)), including the requirement for competent authorities to assess the effects of new and existing consents, permissions and authorisations to ensure that they are not having an adverse effect on the integrity of the site (Regulations 48 and 50). In England and Wales site characterisation, a process which involves the collation, integration and critical evaluation of existing site knowledge, is seen by the Environment Agency (EA) and the nature conservation bodies (English Nature – EN, and the Countryside Council for Wales – CCW) as an important step towards evaluating the effects of consented discharges and activities on the interest features of EMS, and is fundamental to the development of ecosystem-based management. An on-going project, led by the Marine Biological Association of the United Kingdom (part of the Plymouth Marine Science Partnership) in collaboration with EA, EN and CCW, sets out to characterise the impacts and risks associated with water and sediment quality in relation to the integrity and interest features of selected European Marine Sites in southwest England and Wales. Using published information and unpublished data-sets from regulatory agencies, conservation bodies, and research institutes, evidence is compiled on the links between potentially harmful activities, environmental quality and resultant biological effects, and includes an evaluation of long-term change. An overview of results is presented here for one of the UK marine sites studied, The Fal and Helford candidate SAC, highlighting the threats to biota from point-source and diffuse pollutants, together with major gaps in our understanding. Some of the priorities for new research and better integrated monitoring to address nature conservation objectives (to maintain and restore the system) are discussed

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 antifouling 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