Synecology in soft sediment bivalves: the influence of parasites, physiological processes, and environmental stressors on health and disease

Ecosystem goods and services provided by estuarine and near coastal regions are being increasingly recognised for their immense value, as is the biodiversity in these areas and these near coastal communities have been identified as sentinels of climate change also. Population structure and reproductive biology of two bivalve molluscs, Cerastoderma edule and, Mytilus edulis were assessed at two study sites over a 16-month study period. Following an anomalously harsh winter, advancement of spawning time was observed in both species. Throughout Ireland and Europe the cockle has experienced mass surfacings in geographically distinct regions, and a concurrent study of cockles was undertaken to explore this phenomenon. Surfaced and buried cockles were collected on a monthly basis and their health compared. Age was highlighted as a source of variation between dying and healthy animals with a parasite threshold being reached possibly around age three. Local factors dominated when looking at the cause of surfacing at each site. The health of mussels was explored too on a temporal and seasonal basis in an attempt to assess what constitutes a healthy organism. In essence external drivers can tip the balance between “acceptable” levels of infection where the mussel can still function physiologically and “unacceptable” where prevalence and intensity of infection can result in physiological impairment at the individual and population level. Synecological studies of intertidal ecosystems are lacking, so all bivalves encountered during the sampling were assessed in terms of population structure, reproduction, and health. It became clear, that some parasites might specialize on one host species while others are not so specific in host choice. Furthermore the population genetics of the cockle, its parasite Meiogymnophallus minutus, and its hyperparasite Unikaryon legeri were examined too. A small nucleotide polymorphism was detected upon comparison of Ireland and Morocco.

Biodiversity change in the Irish uplands - the effects of grazing management

As a prominent form of land use across much of upland Europe, extensive livestock grazing may hold the key to the sustainable management of these landscapes. Recent agricultural policy reform, however, has resulted in a decline in upland sheep numbers, prompting concern for the biodiversity value of these areas. This study quantifies the effects of varying levels of grazing management on plant, ground beetle and breeding bird diversity and assemblage in the uplands and lowlands of hill sheep farms in County Kerry, Ireland. Farms represent a continuum of light to heavy grazing, measured using a series of field indicators across several habitats, such as the internationally important blanket bog, home to the ground beetle, Carabus clatratus. Linear mixed effects modelling and non-metric multidimensional scaling are employed to disentangle the most influential management and environmental factors. Grazing state may be determined by the presence of Molinia caerulea or Nardus stricta, and variables such as % traditional ewes, % vegetation litter and % scrub prove valuable indicators of diversity. Measures of ecosystem functioning, e.g. plant biomass (nutrient cycling) and % vegetation cover (erosion rates) are influenced by plant diversity, which is influenced by grazing management. Levels of the ecosystem service, soil organic carbon, vary with ground beetle abundance and diversity, potentially influencing carbon sequestration and thereby climate change. The majority of species from all three taxa are found in the lowlands, with the exception of birds such as meadow pipit and skylark. The scale of measurement should be determined by the size and mobility of the species in question. The challenge is to manage these high nature value landscapes using agri-environment schemes which enhance biodiversity by maintaining structural heterogeneity across a range of scales, altitudes and habitats whilst integrating the decisions of people living and working in these marginal areas.

ENVIRON 2011: 21st Irish Environmental Researchers Colloquium

The theme of this year’s colloquium is “Towards 2020: Environmental challenges and opportunities for the next decade” which reflects the many environmental targets that have been set for the year 2020 in areas of climate change, renewable energy, water protection and biodiversity. In relation to the latter, we are delighted to have Professor Michael Depledge (Former Chairman of UK Science Advisory Committee on the Environment & Climate Change) at ENVIRON 2011 to deliver the colloquium keynote address on “Health and the Value of Nature”. The colloquium plenary session has a number of high profile speakers who will address the colloquium theme of environmental challenges and opportunities for the next decade including Professor John Sweeney (NUI Maynooth), Ms Laura Burke (Director of EPA’s Office of Climate, Licensing Research and Resource Use) and Mr John Mullins (CEO of Bord Gais). The research programme has 95 oral presentations and 60 poster presentations in the themes of water quality, energy and climate change, marine and coastal research, environmental management, environmental technologies, environment and health, and biodiversity and ecosystems. In addition, for the first year, poster presenters have the opportunity to make a 1 minute oral presentation on their poster during the oral sessions in the relevant theme. The 2011 colloquium also sees an increase the number of workshops and seminars accompanying the programme with an emphasis on training and development for postgraduates in the environmental area. We are particularly pleased to have a link with the Environment Graduate Programme in the “Ocean Studies Workshop” which illustrates how the ENVIRON colloquium can support and benefit from the various graduate programmes currently being developed within Universities. Finally ENVIRON 2011 and the UCC 2011 Law and the Environment symposium have been deliberately scheduled together at the same time and location to allow delegates from both conferences to benefit from each other’s programmes.