Managing Endangered Species Within the Use–Preservation Paradox: The Florida Manatee (Trichechus manatus latirostris) as a Tourism Attraction

A significant challenge to wildlife managers in tourism settings is to provide visitors with opportunities to observe rare and endangered wildlife while simultaneously protecting the target species from deleterious impacts. Nearly 100,000 people annually visit Crystal River, Florida, USA to observe and swim with the Florida manatee, an endangered species. This research aimed to investigate and describe human-manatee interactions in a tourism context, to understand the salient issues related to such interactions as identified by stakeholders, and to recommend a course of action to address multiple interests in the planning and management of human-manatee interactions. Five issues were identified by all stakeholder groups: water quality, harassment, density and crowding, education, and enforcement. Currently, the U.S. Fish and Wildlife Service, which is responsible for manatee management, does not have mechanisms in place to manage the tourism component of the manatee encounter. Although a regulatory approach can be taken, a better approach would be to create an organization of tour operators to establish "best practices" that reflect the goal of the managing agency to enhance manatee protection (and thus ensure their livelihood) and to enhance the visitor experience.     

Selecting suitable sites for animal waste application using a raster GIS

Rapid growth of intensive animal industries in southeast Queensland, Australia, has led to large volumes of animal waste production, which posses serious environmental problems in the Murray Darling Basin (MDB). This study presents a method of selecting sites for the safe application of animal waste as fertiliser to agricultural land. A site suitability map for the Westbrook subcatchment within the MDB was created using a geographic information system (GIS)-based weighted linear combination (WLC) model. The factors affecting the suitability of a site for animal waste application were selected, and digital data sets derived from up to 1:50,000 scale maps were acquired. After initial preprocessing, digital data sets were clipped to the size of the delineated subcatchment boundary producing input factors. These input factors were weighted using the analytical hierarchy process (AHP) that employed an objectives-oriented comparison (OOC) technique to formulate the pairwise comparison matrix. The OOC technique, which is capable of deriving factor weight independently, formulated the weight derivation process by making it more logical and systematic. The factor attributes were classified into multiple classes and weighted using the AHP. The effects of the number of input factors and factor weighting on the areal extent and the degree of site suitability were examined. Due to the presence of large nonagricultural and residential areas in the subcatchment, only 16% of the area was found suitable for animal waste application. The areal extent resulting from this site suitability assessment was found to be dependent on the areal constraints imposed on each input factor, while the degree of suitability was principally a function of the weight distribution between the factors.     

Computer Inference Of Network Of Ecological Interactions From Sampling Data

Both direct and indirect ecological interactions may occur in an ecosystem with large numbers of taxa. Traditional food web technique is a popular tool to measure the quality and health of the environment. Much of works must be done before constructing a food web for an ecosystem especially with many taxa. This food web is generally specific for some ecological interactions and fixed for a set of given species. It is therefore not an effective method for dynamic and prompt assessment of environment. Ecological interactions and their interactive intensity may be detected by sampling biological taxa in the field and by detecting various between-taxa distances or similarities. Network may clearly exhibit the complex interactions among biological taxa. Statistic tests on various distance or similarity measures and computer designs are required to infer the {network. We develop an algorithm and software to infer the network of direct or indirect ecological interactions in ecosystem. It is a prompt and effective tool in monitoring and assessment of the environment. A redundant network may be inferred and drawn by computer based on the statistic tests on sampling data or the pathway information given in HTML file. Dominant taxa may be found in the network. In total of 16 distance and similarity measures, including Euclidean distance, Manhattan distance, Pearson correlation, partial correlation, point correlation, linkage coefficients, Jaccard coefficient etc., are provided to detect taxa pairs with significant parametric or nonparametric similarities, based on randomization tests and ordinary statistic tests. Criteria to use distance and similarity measures are discussed.     

Comprehensive study on dioxin contents in binder and anti-caking agent feed additives

Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were determined in some additives widely employed as binder and anti-caking agents in feedstuffs, such as kaolin, bentonite, zeolite, etc. with an special attention on sepiolite samples. Owing to their physico-chemical properties, the little information of these materials reported in the literature, the variability of PCDDs/PCDFs found in a preliminary evaluation and the absence of reference materials highlighted further research needed. Therefore, an extensive study on the analytical procedures based on the classical methods was performed with sepiolite samples. The study includes evaluation of reproducibility and repeatibility. To this end, a series of intra-day and nine inter-day analysis were made. The methodolgy was also assessed against the sample size and series of 12.5, 25, 37.5 and 50 g were analyzed. In all cases, the results confirmed good correlation with the parameters evaluated.