Parasite tags in ecological studies of terrestrial hosts: a study on ptarmigan (Lagopus spp.) dispersal

The spatial distributions of parasites may provide valuable information in studies on host ecology. This study was conducted in Troms County, Northern Norway, and focussed on the spatial and temporal variation in abundance of two nematode parasites, Ascaridia compar and Trichostrongylus tenuis, infecting the gastrointestinal tract of Willow Ptarmi-gan (Lagopus lagopus) and Rock Ptarmigan (Lagopus mutus). In an inland area preva-lence of A. compar varied between 52.2–78.1% in September during 6 years of sampling, and in a coastal area that was sampled for 10 years, the prevalence of T. tenuis ranged be-tween 25.0–75.4%. Both nematodes attained significantly higher prevalences in willow ptarmigan than in Rock Ptarmigan. The nematodes showed marked differences in geo-graphical distributions in September, where A. compar was common at inland localities while T. tenuis only was found in hosts at coastal islands. Practical use of these parasites as biological tags suggested a coast to inland winter dispersal in Rock Ptarmigan, especially among juvenile hens, but no dispersal was recorded in Willow Ptarmigan. The use of bio-logical tags in general and the use of nematodes as indicators of ptarmigan dispersal are discussed

Site characterisation of a basin-scale CO(2) geological storage system: Gippsland Basin, southeast Australia

Geological storage of CO in the offshore Gippsland Basin, Australia, is being investigated by the Cooperative Research Centre for Greenhouse Gas Technologies (CO2CRC) as a possible method for storing the very large volumes of CO emissions from the nearby Latrobe Valley area. A storage capacity of about 50 million tonnes of CO per annum for a 40-year injection period is required, which will necessitate several individual storage sites to be used both sequentially and simultaneously, but timed such that existing hydrocarbon assets will not be compromised. Detailed characterisation focussed on the Kingfish Field area as the first site to be potentially used, in the anticipation that this oil field will be depleted within the period 2015-2025. The potential injection targets are the interbedded sandstones of the Paleocene-Eocene upper Latrobe Group, regionally sealed by the Lakes Entrance Formation. The research identified several features to the offshore Gippsland Basin that make it particularly favourable for CO storage. These include: a complex stratigraphic architecture that provides baffles which slow vertical migration and increase residual gas trapping and dissolution; non-reactive reservoir units that have high injectivity; a thin, suitably reactive, lower permeability marginal reservoir just below the regional seal providing mineral trapping; several depleted oil fields that provide storage capacity coupled with a transient production-induced flow regime that enhances containment; and long migration pathways beneath a competent regional seal. This study has shown that the Gippsland Basin has sufficient capacity to store very large volumes of CO. It may provide a solution to the problem of substantially reducing greenhouse gas emissions from future coal developments in the Latrobe Valley