Identification of environmentally vulnerable areas with priority for prevention and management of pipeline crude oil spills

The oil industry is one of the main productive activities in Mexico and has a huge infrastructure, including a wide pipeline network that crosses urban, industrial, agricultural and natural areas. The threat of crude oil spills is greatest in those regions with a high concentration of oil extraction and refining activities, as in the case of the Coatzacoalcos and Tonalá Rivers Low Basin. This study ranked the geosystems of the basin in terms of vulnerability to pipeline crude oil spills. Very high vulnerability (level I) was assigned to the water bodies (lakes and rivers) and their margins of influence, including surfaces that flood during normal hydraulic load. High vulnerability areas (level II) comprised surfaces that can flood during extraordinary hydraulic load related with extreme hydrometeorological events. The remaining three vulnerability levels were defined for areas with low or negligible flooding potential, these were ranked according to physical (slope, relief and permeability), biological (richness, singularity and integrity) and socio-economic (social marginalization index and economic activities index) conditions. These results are presented on a map for better visualization and interpretation. This study will be useful to establish preventive and effective emergency management actions in order to reduce remediation costs and adverse effects on wild species. It also can help local and national authorities, oil industry and civil protection corps to better protect ecosystems, natural resources and human activities and goods.     

Monitoring ammonia in urban, inner alpine and pre-alpine ambient air

Passive samplers were used to monitor ammonia concentrations at rural inner alpine and pre-alpine, as well as urban, sites in Austria and Bavaria. Elevated concentrations were measured both at farms (up to 36 microg NH3 m(-3)) and at urban locations (up to 28 microg NH3 m(-3)). At urban locations a linear relationship between the traffic density and the NH3 concentration was found, but there was no marked seasonal trend. The highest ammonia concentrations were measured in a traffic tunnel (up to 78 microg NH3 m(-3)). The presence of livestock breeding or small scale alpine pastures resulted in elevated concentrations at the rural sites (8.1-12 and 2.5-4.6 microg NH3 m(-3), respectively), compared to the surrounding areas (3.1 and 0.9 microg NH3 m(-3)). Agriculture related sources are usually limited either spatially or seasonally. As the emissions were moderate in our case, a rapid removal and dilution of ammonia was possible and therefore the NH3 burden was only local. Sources related to traffic are more evenly distributed both geographically and seasonally. The WHO guideline, annual average concentration of 8 microg m(-3) for the protection of vegetation, was only exceeded at farms, at the urban station with the heaviest traffic and in the Tauerntunnel.     

Dominance in feeding territories relates to foraging success and offspring growth in brown skuas <Emphasis Type="Italic">Catharacta antarctica lonnbergi</Emphasis>

Territoriality should lead to strict dominance, as territory holders typically control access to resources and exclude others from their use. In feeding territories, dominance should be reflected in foraging success and ultimately in reproduction differences; however, these successive links have rarely been made explicit. Therefore, we investigated a population of brown skuas Catharacta antarctica lonnbergi, in which only part of the breeding population occupied feeding territories within penguin colonies. We identified the dominance hierarchy and determined the foraging success of the participants in fights for access to penguin carcasses within the territories. Furthermore, we monitored offspring growth from parents with and without feeding territories. Our results indicated a clear dominance hierarchy with territorial birds in their own territory dominating over territorial breeders from other territories, non-territorial breeders and non-breeding birds. However, territory owners could not completely exclude others from access to food. Foraging success was positively related to dominance scores: The dominant territory owners received 63% of a carcass, whereas non-territorial pairs could get less than 10%. The link between foraging success and offspring development was less clear: Although male chicks of non-territorial parents suffered from lower growth rates and, thus, delayed fledging, there were no such differences in female chicks. Territoriality in skuas did not imply a complete occupation of food, but guaranteed optimal growth conditions for offspring. Non-territorial individuals were forced to search for alternative resources, and the restricted access to the preferred food resulted in inferior conditions for offspring development, making this foraging strategy less rewarding.     

Suitability of the vegetation types in Mexico's Tamaulipas state for the siting of hazardous waste treatment plants

A land suitability study was carried out by applying a multiple-criteria technique to 12 different vegetation types in Mexico's Tamaulipas state to help select potentially suitable sites for hazardous waste treatment plants. Species richness, spatial distribution, and uniqueness were selected as the criteria for estimating a vegetation type's suitability. Using the analytical hierarchy process, we ranked and mapped vegetation types, then compared the results with rankings of the same vegetation types based only on their number of endemic species. The suitabilities of the various vegetation types were ordered in more or less the same way by both methods, except in two cases for which the results were very different. The method proved to be a useful tool despite the availability of only partial (mostly qualitative) information; under such circumstances, expert experience can be incorporated in the evaluation process to a limited degree. The technique described in this paper has a high potential to aid decisions when many opinions and options must be considered simultaneously.     

Declining populations of freshwater pearl mussels (Margaritifera margaritifera) are burdened with heavy metals and DDT/DDE

Many aquatic mollusks, such as the freshwater pearl mussel (Margaritifera margaritifera), are in decline throughout Europe. The reasons are largely unknown; factors that have been suggested to contribute are river bed compaction due to agricultural practices, eutrophication, or pollutants of various natures. Brittle shells of recently deceased pearl mussels from northern Bavaria with weak calcium incrustations point to the possibility that calcium metabolism is affected. It is known that certain persistent organic pollutants and some heavy metals may induce calcium deficiency in wildlife. Elevated levels of the organochlorine insecticide DDT and its metabolite DDE, as well as of cadmium and some other heavy metals, have been found in pearl mussels. Both classes of environmental pollutants are known to potentially interfere with calcium homeostasis.     

Bill color, not badge size, indicates testosterone-related information in house sparrows

The honesty of ornamental signals of quality is often argued to be enforced via costs associated with testosterone. It is still poorly understood, however, how seasonal variation of testosterone within individuals is related to the timing and extent of ornament development. Here, we studied inter- and intra-individual variability of plasma testosterone levels in a population of 150 captive male house sparrows (Passer domesticus) through the course of a full year. We further analyzed the relationship between plasma testosterone levels and two sexually dimorphic ornaments: badge size and bill coloration. Also, because of a known negative relation between molt and circulating testosterone levels, we analyzed the relationship between ornamentation and molt status during the fall. We found that testosterone levels increased towards the breeding season and decreased before the onset of annual molt. However, within individuals, relative testosterone titers demonstrated low repeatability between seasons. Plasma testosterone levels were not correlated with badge size in any season but were correlated strongly with bill coloration during all periods, except the breeding season when variation in bill color was low. Finally, we found that bill coloration strongly correlated with molt status during fall. Our results indicate that bill coloration, not badge size, is the best ornamental indicator of a “running average” of male testosterone in house sparrows and therefore the best potential indicator of qualities and/or behavioral strategies associated with testosterone.     

Development of an individual-based model to evaluate elk (Cervus elaphus nelsoni) movement and distribution patterns following the Cerro Grande Fire in north central New Mexico, USA

Though studies have modeled the effects of fires on elk, no studies have related the effects of post-fire landscape succession on ungulate movements and distribution using dynamic modeling techniques. The purpose of this study was to develop and test a spatially-explicit, stochastic, individual-based model (IBM) to evaluate potential movement and distribution patterns of elk (Cervus elaphus nelsoni) in relation to spatial and temporal aspects of the Cerro Grande Fire that burned north central New Mexico in May of 2000. Following extensive literature review, the SAVANNA Ecosystem Model was selected to simulate the underlying post-fire successional processes driving elk movement and distribution. Standard logisitic regression was used to analyze habitat-use patterns of ten elk from data collected using global positioning system radio collars while an additional five animals were used as an independent test set during model validation. Static variables in the form of roads, buildings, fences, and habitual use/memory were used to modify a map of impedance values based on the logistic regression of slope, aspect, and elevation. Integration with SAVANNA came through the application of a habitat suitability index (HSI), which combined movement rules written for the IBM and variables modified and produced by the dynamic ecological processes run in SAVANNA. Overall pattern analysis indicated that realistic migrational processes and habitat-use patterns emerged from movement rules incorporated into the IBM in response to advancing and receding snow when compared to the independent test set. Primary and secondary movement pathways emerged from the collective responses of simulated individuals. Using regression analyses, no significant differences between simulated animals and animals used in either model development or an independent test set revealed any differences in response to snow patterns. These considerations suggest the model was adequately corroborated based on existing data and outlined objectives.