An evaluation of the applicability of microarrays for monitoring toxic algae in Irish coastal waters

The applicability of microarrays to monitor harmful algae across a broad range of ecological niches and toxic species responsible for harmful algal events has been one of the key tasks in the EU Seventh Framework Programme (FP7)-funded Microarrays for the Detection of Toxic Algae project. The technique has a strong potential for improving speed and accuracy of the identification of harmful algae and their toxins to assist monitoring programmes. Water samples were collected from a number of coastal sites around Ireland, including several that are used in the Irish National Phytoplankton and Biotoxin Monitoring Programme. Ribosomal RNA was extracted from filtered field samples, labelled with a fluorescent dye, and hybridised to probes spotted in a microarray format on a glass slide. The fluorescent signal intensity of the hybridisation to >120 probes on the chip was analysed and compared with actual field counts. There was a general agreement between cell counts and microarray signal. Results are presented for field samples taken from a range of stations along the Irish coastline known for harmful algal events during the first field trial (July 2009–April 2010).     

Mustached males in a tropical poeciliid fish: emerging female preference selects for a novel male trait

One possible mechanism for the (co-)evolution of seemingly novel male traits and female preferences for them is that males exploit pre-existing female biases, and livebearing fishes (Poeciliidae) have been at the forefront of this research for almost two decades. Here, using 13 poeciliid species from four different genera, we tested whether mustache-like rostral filaments found in males of some Mexican molly (Poecilia sphenops) populations could have evolved due to exploitation of a pre-existing female bias. While Mexican mollies were the only species with a significant female association preference for mustached males, we also did not find any species exhibiting significant aversion for mustached males; rather, variance in female preference scores was large throughout. For example, more than 25% of females spent twice as much time with the mustached male compared to the non-mustached male in most species, but even 31% of Mexican molly females spent more time near the non-mustached male. Hence, a comparison of the strength of preference was inconclusive. We discuss the possibility that the female preference of P. sphenops for mustached males could be due to a female pre-existing bias (sensu lato), even if population means were not significant for species other than P. sphenops. This highlights the importance of distinguishing between population means and individual preferences when interpreting mate choice, and thus, adds depth to the concept of mating preferences as a motor for evolutionary change.     

Review of submarine groundwater discharge (SGD) in coastal zones of the Southeast and Gulf Coast regions of the United States with management implications

Groundwater serves as the primary drinking water source for over half of the coastal populations of the Southeast and Gulf Coast regions, two of the fastest growing regions in the United States. Increased demand for this resource has exceeded sustainable yields in many areas and induced saltwater intrusion of coastal aquifers. A process associated with coastal groundwater, submarine groundwater discharge (SGD), has been documented as a source of subsurface fluids to coastal ocean environments throughout the Southeast and Gulf Coast regions and is potentially a significant contributor to nearshore water and geochemical budgets (i.e., nutrients, carbon, trace metals) in many coastal regions. The importance of groundwater as a drinking water source for coastal populations and the influences of submarine groundwater discharge to the coastal ocean warrant increased research and management of this resource. This paper highlights findings from recent SGD studies on three hydrogeologically different continental margins (Onslow Bay, NC, southern Florida, and the Louisiana margin), provides background on the common methods of assessing SGD, and suggests a regional management plan for coastal groundwater resources. Suggested strategies call for assessments of SGD in areas of potentially significant discharge, development of new monitoring networks, and the incorporation of a regional coastal groundwater resources council.     

Evaluating Aggregate Terrestrial Impacts of Road Construction Projects for Advanced Regional Mitigation

This study presents a GIS-based database framework used to assess aggregate terrestrial habitat impacts from multiple highway construction projects in California, USA. Transportation planners need such impact assessment tools to effectively address additive biological mitigation obligations. Such assessments can reduce costly delays due to protracted environmental review. This project incorporated the best available statewide natural resource data into early project planning and preliminary environmental assessments for single and multiple highway construction projects, and provides an assessment of the 10-year state-wide mitigation obligations for the California Department of Transportation. Incorporation of these assessments will facilitate early and more strategic identification of mitigation opportunities, for single-project and regional mitigation efforts. The data architecture format uses eight spatial scales: six nested watersheds, counties, and transportation planning districts, which were intersected. This resulted in 8058 map planning units statewide, which were used to summarize all subsequent analyses. Range maps and georeferenced locations of federally and state-listed plants and animals and a 55-class landcover map were spatially intersected with the planning units and the buffered spatial footprint of 967 funded projects. Projected impacts were summarized and output to the database. Queries written in the database can sum expected impacts and provide summaries by individual construction project, or by watershed, county, transportation district or highway. The data architecture allows easy incorporation of new information and results in a tool usable without GIS by a wide variety of agency biologists and planners. The data architecture format would be useful for other types of regional planning.     

An engineering-economic model of pipeline transport of CO2 with application to carbon capture and storage

Carbon dioxide capture and storage (CCS) involves the capture of CO₂ at a large industrial facility, such as a power plant, and its transport to a geological (or other) storage site where CO₂ is sequestered. Previous work has identified pipeline transport of liquid CO₂ as the most economical method of transport for large volumes of CO₂. However, there is little published work on the economics of CO₂ pipeline transport. The objective of this paper is to estimate total cost and the cost per tonne of transporting varying amounts of CO₂ over a range of distances for different regions of the continental United States. An engineering-economic model of pipeline CO₂ transport is developed for this purpose. The model incorporates a probabilistic analysis capability that can be used to quantify the sensitivity of transport cost to variability and uncertainty in the model input parameters. The results of a case study show a pipeline cost of US$ 1.16 per tonne of CO₂ transported for a 100 km pipeline constructed in the Midwest handling 5 million tonnes of CO₂ per year (the approximate output of an 800 MW coal-fired power plant with carbon capture). For the same set of assumptions, the cost of transport is US$ 0.39 per tonne lower in the Central US and US$ 0.20 per tonne higher in the Northeast US. Costs are sensitive to the design capacity of the pipeline and the pipeline length. For example, decreasing the design capacity of the Midwest US pipeline to 2 million tonnes per year increases the cost to US$ 2.23 per tonne of CO₂ for a 100 km pipeline, and US$ 4.06 per tonne CO₂ for a 200 km pipeline. An illustrative probabilistic analysis assigns uncertainty distributions to the pipeline capacity factor, pipeline inlet pressure, capital recovery factor, annual O&M cost, and escalation factors for capital cost components. The result indicates a 90% probability that the cost per tonne of CO₂ is between US$ 1.03 and US$ 2.63 per tonne of CO₂ transported in the Midwest US. In this case, the transport cost is shown to be most sensitive to the pipeline capacity factor and the capital recovery factor. The analytical model elaborated in this paper can be used to estimate pipeline costs for a broad range of potential CCS projects. It can also be used in conjunction with models producing more detailed estimates for specific projects, which requires substantially more information on site-specific factors affecting pipeline routing.     

Chromosomal mosaicism: Origins and clinical implications in preimplantation and prenatal diagnosis

The diagnosis of chromosomal mosaicism in the preimplantation and prenatal stage is fraught with uncertainty and multiple factors need to be considered in order to gauge the likely impact. The clinical effects of chromosomal mosaicism are directly linked to the type of the imbalance (size, gene content, and copy number), the timing of the initial event leading to mosaicism during embryogenesis/fetal development, the distribution of the abnormal cells throughout the various tissues within the body as well as the ratio of normal/abnormal cells within each of those tissues. Additional factors such as assay noise and culture artifacts also have an impact on the significance and management of mosaic cases. Genetic counseling is an important part of educating patients about the likelihood of having a liveborn with a chromosome abnormality and these risks differ according to the time of ascertainment and the tissue where the mosaic cells were initially discovered. Each situation needs to be assessed on a case-by-case basis and counseled accordingly. This review will discuss the clinical impact of finding mosaicism through: embryo biopsy, chorionic villus sampling, amniocentesis, and noninvasive prenatal testing using cell-free DNA.     

Habitat selection increases the isolating effect of habitat fragmentation on the gopher tortoise

Habitat selection requires choice, which differentiates it from habitat use, and choice, in turn, is dependent upon the responses of organisms to the environmental, social, and other cues that they perceive. Habitat selection by the gopher tortoise (Gopherus polyphemus) was investigated by translocating tortoises and monitoring their movements within two sites in central Florida. The first site supported a stable preponderance of high-quality habitat, and tortoises avoided areas with a dense tree canopy cover caused by fire exclusion. The second site was badly invaded by an introduced weed, and tortoises avoided areas where the weed had formed a dense monoculture. At both sites, individuals appeared to be responding to visual cues to avoid areas that were relatively dark. In landscapes with relatively large amounts of high-quality habitat, this avoidance behavior serves the gopher tortoise well by keeping individuals within the dominant habitat type. In degraded areas, high-quality habitat often becomes increasingly uncommon, and the avoidance behavior exhibited by the tortoises will result in individuals becoming confined to small patches, causing a significant reduction in fitness and hence questioning their long-term survival in such areas. The results from our study show that in order to maintain viable tortoise populations in areas increasingly subjected to human fragmentation and degradation, it is crucial not only to suppress tree canopy cover continually and prevent invasion by exotic weeds, but also to be mindful that the avoidance behavior of the gopher tortoise could prevent individuals from fully occupying a high-quality habitat in response to restoration and management efforts.