Modelling the responses of wildlife to human disturbance: An evaluation of alternative management scenarios for black-crowned night-herons

The impact of anthropogenic disturbance on wildlife is increasing becoming a source of concern as the popularity of outdoor recreation rises. There is now more pressure on site managers to simultaneously ensure the continued persistence of wildlife and provide recreational opportunities. Using ‘Simulation of Disturbance Activities’, a model designed to investigate the impact of recreational disturbance on wildlife, we demonstrate how a simulation modelling approach can effectively inform such management decisions. As an example, we explored the implications of various design and management options for a proposed recreational area containing a historic breeding bird colony. By manipulating the proximity, orientation and intensity of recreation, we were able to evaluate the impact of recreational activities on the behaviour of black-crowned night-heron nestlings (Nycticorax nycticorax). Using a classification and regression tree (CART) procedure to analyse simulation output, we explored the dynamics of multiple strategies in concert. Our analysis revealed that there are inherent advantages in implementing multiple strategies as opposed to any single strategy. Nestlings were not disturbed by recreation when bird-watching facility placement (proximity and orientation) and type were considered in combination. In comparison, proximity alone only led to a <10% reduction in disturbance. Thus we demonstrate how simulation models based on customised empirical data can bridge the gap between field studies and active management, enabling users to test novel management scenarios that are otherwise logistically difficult. Furthermore, such models potentially have broad application in understanding human-wildlife interactions (e.g. exploring the implications of roads on wildlife, probability of bird strikes around airports, etc.). They therefore represent a valuable decision-making tool in the ecological design of urban infrastructures.     

The Importance of Place Names in the Search for Ecosystem-Like Concepts in Indigenous Societies: An Example from the Bolivian Andes

This paper aims to deepen the search for ecosystem-like concepts in indigenous societies by highlighting the importance of place names used by Quechua indigenous farmers from the central Bolivian Andes. Villagers from two communities in the Tunari Mountain Range were asked to list, describe, map and categorize the places they knew on their community’s territory. Results show that place names capture spatially explicit units which integrate biotic and abiotic nature and humans, and that there is an emphasis on topographic terms, highlighting the importance of geodiversity. Farmers’ perspectives differ from the classical view of ecosystems because they ‘humanize’ places, considering them as living beings with agency. Consequently, they do not make a distinction between natural and cultural heritage. Their perspective of the environment is that of a personalized, dynamic relationship with the elements of the natural world that are perceived as living entities. A practical implication of the findings for sustainable development is that since places names make the links between people and the elements of the landscape, toponymy is a tool for ecosystem management rooted in indigenous knowledge. Because place names refer to holistic units linked with people’s experience and spatially explicit, they can be used as an entry point to implement an intercultural dialogue for more sustainable land management.     

A model for estimating the impact of the domino effect on accident frequencies in quantitative risk assessments of storage facilities

It is well known that the domino effect can have a major impact on accidents in storage facilities, as it can increase the consequences of an initial event considerably. However, quantitative risk assessments (QRAs) do not usually take the domino effect into account in a detailed, systematic way, mostly because of its complexity and the difficulties involved in its incorporation. We have developed a simple method to include the domino effect in QRAs of storage facilities, by estimating the frequency with which new accidents will occur due to this phenomenon. The method has been programmed and implemented in two case studies. The results show that it can indeed be used to include the possibility of domino effect occurrence in a QRA. Furthermore, depending on the design of a facility, the domino effect can have a significant effect on the associated risk.     

Study on PCDDs/PCDFs and co-PCBs content in food samples from Catalonia (Spain)

The results of a surveillance programme on polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and co-planar polychlorinated biphenyls (co-PCBs) determination in 70 foodstuffs samples produced all over the four provinces of Catalonia is presented. The study included the analyses of raw milk, pure virgin olive oil, butter, chicken, pork and mussel samples collected between November 1999 and January 2000. Milk, virgin oil, pork or butter presented a variable dioxin and co-PCBs content, even though the limits proposed in the draft of the EC Regulation for its commercialization in the European countries were not reached. The levels of PCDDs/PCDFs and co-PCBs determined in chicken samples varied between 0.36–3.59 pg I-TEQ/g fat chicken (0.4–3.8 WHO-TEQ/g fat). Just one case presented remarkable content of dioxins (about 30 pg I-TEQ/g fat) with a complex congener-specific profile which indicates the presence of an external contamination. On the other hand, a congener-specific profile dominated by 2,3,7,8-TCDF and OCDD was observed in mussel samples from Catalonia. This fact was also observed in mussel samples from other sites in Spain.     

Mercury bioaccumulation and phytotoxicity in two wild plant species of Almadén area

Mercury is a widely distributed environmental pollutant, able to induce toxicity in living organisms, including higher plants. Some plant species are able to grow in mine sites, like the Almadén zone in Spain. Our study focus on two of these plant species, Rumex induratus and Marrubium vulgare and their responses to natural Hg exposure. Total Hg concentration in the soil below the plants could be classified as toxic, although the available fraction was low. Hg availability was higher for the M. vulgare than for the R. induratus plot. Hg concentrations in field plants of R. induratus and M. vulgare grown on these soils can be considered as phytotoxic, although no symptoms of Hg toxicity were observed in any of them. According to the BAF ([Hg]_tissue/[Hg]_avail), R. induratus showed a higher ability in Hg uptake and translocation to shoots, as well as higher concentrations of MDA and –SH:Hg ratios, so that this plant is more sensitive to Hg than M. vulgare. The resistance to Hg and the capability to extract Hg from the soil make both M. vulgare and R. induratus good candidates for Hg phytoremediation of contaminated soils.     

Natural attenuation of residual heavy metal contamination in soils affected by the Aznalcóllar mine spill, SW Spain

Non-amended soils affected by pyritic sludge residues were monitored for 7 years to assess the long-term natural attenuation ability of these soils. The decrease in both the total concentration of elements (particularly As) and (NH(4))(2)SO(4)-extractable fractions of Mn, and Zn, below the maximum permissible levels indicate a successful natural ability to attenuate soil pollution. Soil acidification by pyrite oxidation and rainfall-enhanced leaching were the largest contributors to the reduction of metals of high (Mn, Cu, Zn and Cd) and low (Fe, Al, and As) availability. Periodic use of correlation and spatial distribution analysis was useful in monitoring elemental dispersion and soil property/element relationships.     

The key role played by the Augusta basin (southern Italy) in the mercury contamination of the Mediterranean Sea

The Augusta basin, located in SE Sicily (southern Italy), is a semi-enclosed marine area, labelled as a highly contaminated site. The release of mercury into the harbour seawater and its dispersion to the blue water, make the Augusta basin a potential source of anthropogenic pollution for the Mediterranean Sea. A mass balance was implemented to calculate the HgT budget in the Augusta basin. Results suggest that an average of ～0.073 kmol of HgT is released, by diffusion, on a yearly basis, from sediments to the seawater, with a consequent output of 0.162 kmol y(-1) to coastal and offshore waters; this makes the Augusta area an important contributor of mercury to the Mediterranean Sea. Owing to the geographical location of the Augusta basin, its outflowing shelf-waters are immediately intercepted by the surface Atlantic Ionian Stream (AIS) and mixed with the main gyres of the eastern Mediterranean Sea, thus representing a risk for the large-scale marine system.     

Surveillance programme on dioxin levels in ambient air sites in Catalonia (Spain)

As part of a survey programme conducted by the Environment Department of the Autonomous Government of Catalonia in collaboration with the Spanish Council for Scientific Research (CSIC), dioxin concentrations in ambient air were measured in the four provinces of Catalonia (Spain). The study was also performed with the intention of providing data as a basis for future monitoring and evaluation of temporal trends in ambient air. Thus, 91 samples were collected in 25 different sites (rural, urban, suburban and industrial) between 1994 and 2000. The levels revealed a variable content of PCDDs/PCDFs depending both on the area and the contamination source. In particular, industrial areas presented levels ranging from 18 to 954 fg I-TEQ/m3. However, findings in urban and suburban sites varied between 13 and 357 fg I-TEQ/m3. As expected, the lowest levels were found in rural areas with levels between 5 and 125 fg I-TEQ/m3.     

Hazardous air pollutants from mobile sources in the Metropolitan Area of Mexico City

Environmental agencies are currently in the process of implementing a new air management program, which includes the improvement of fuel quality. In this work, exhaust emissions data and estimated relative risk for various fuels testing in-use vehicles, equipped with three different exhaust emission control technologies, are presented. Aromatics, sulfur, and olefins contents; type of oxygenated compound; and Reid vapor pressure were varied. The aim also includes calculating the ozone (O3) forming potential and a relative cancer risk of emissions from current and formulated gasoline blends in Mexico. The proposed gasoline decreases carbon monoxide, total hydrocarbons (THC), and nitrogen oxides emissions by 18 and 14%, respectively, when compared with gasoline sold in the rest of the country and within ozone nonattainment metropolitan areas in Mexico, respectively.