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T.P. Boyle

Publications and source records attributed to T.P. Boyle.

10 recordsLinked to original sources

Landsat TM inventory and assessment of waterbird habitat in the southern altiplano of South America

The diverse set of wetlands in southern altiplano of South America supports a number of endemic and migratory waterbirds. These species include endangered endemic flamingos and shorebirds that nest in North America and winter in the altiplano . This research developed maps from nine Landsat Thematic Mapper (TM) images (254,300 km 2 ) to provide an inventory of aquatic waterbird habitats. Image processing software was used to produce a map with a classification of wetlands according to the habitat requirements of different types of waterbirds. A hierarchical procedure was used to, first, isolate the bodies of water within the TM image; second, execute an unsupervised classification on the subsetted image to produce 300 signatures of cover types, which were further subdivided as necessary. Third, each of the classifications was examined in the light of field data and personal experience for relevance to the determination of the various habitat types. Finally, the signatures were applied to the entire image and other adjacent images to yield a map depicting the location of the various waterbird habitats in the southern altiplano . The data sets referenced with a global positioning system receiver were used to test the classification system. Multivariate analysis of the bird communities censused at each lake by individual habitats indicated a salinity gradient, and then the depth of the water separated the birds. Multivariate analysis of the chemical and physical data from the lakes showed that the variation in lakes were significantly associated with difference in depth, transparency, latitude, elevation, and pH. The presence of gravel bottoms was also one of the qualities distinguishing a group of lakes. This information will be directly useful to the Flamingo Census Project and serve as an element for risk assessment for future development.

Wetlands Ecology and Management

Natural and anthropogenic factors affecting the structure of the benthic macroinvertebrate community in an effluent-dominated reach of the Santa Cruz River, AZ

This study provides an assessment of the ecological conditions of a 46-km effluent-dominated stream section of the Santa Cruz River in the vicinity of the International Waste Water Treatment Plant, Nogales, AZ. We associated changes in the structure of the macroinvertebrate community to natural and anthropogenic chemical and physical variables using multivariate analysis. The analysis shows that biological criteria for effluent-dominated streams can be established using macroinvertebrate community attributes only with an understanding of the contribution of three classes of variables on the community structure: (1) low flow hydrological discharge as affected by groundwater withdrawals, treatment plant discharge, and subsurface geomorphology; (2) chemical composition of the treatment plant discharge and natural dilution; and (3) naturally produced floods resulting from seasonality of precipitation. ?? 2003 Elsevier Science Ltd. All rights reserved.

Ecological Indicators

The status of the macroinvertebrate community in the St. Croix River, Minnesota and Wisconsin: An examination of ecological health using techniques of multivariate analysis

A statistical procedure that integrates physical, chemical and biological data is used to operationally define and analyze ecological health. Benthic macroinvertebrates collected from May through September from eight locations along the St. Croix River in Minnesota and Wisconsin were analyzed by canonical correspondence analyses. A sequential multivariate analysis procedure was developed that included: 1) determining which environmental variables explained the most variation in the taxonomic data, individually and collectively, 2) running canonical correspondence analyses on the taxonomic data along with environmental variables chosen from a stepwise forward selection procedure, 3) performing a cluster analysis of the taxonomic data in sampling times to determine artificial biological seasons, and 4) analyzing the seasonal data (three time intervals) separately, as in steps 1 and 2. Changes in community structure were significantly associated with changes in environmental factors (physical and chemical) that varied in time and space. The variables found to be significant were largely those expected to be associated with the variations in the structure of benthic macroinvertebrate community in an unimpacted river. A slight influence of nitrogen could be detected in agricultural areas.

Minnesota, Wisconsin

An approach for assessment of water quality using semipermeable membrane devices (SPMDs) and bioindicator tests

As an integral part of our continued development of water quality assessment approaches, we combined integrative sampling, instrumental analysis of widely occurring anthropogenic contaminants, and the application of a suite of bioindicator tests as a specific part of a broader survey of ecological conditions, species diversity, and habitat quality in the Santa Cruz River in Arizona, USA. Lipid-containing semipermeable membrane devices (SPMDs) were employed to sequester waterborne hydrophobic chemicals. Instrumental analysis and a suite of bioindicator tests were used to determine the presence and potential toxicological relevance of mixtures of bioavailable chemicals in two major water sources of the Santa Cruz River. The SPMDs were deployed at two sites; the effluent weir of the International Wastewater Treatment Plant (IWWTP) and the Nogales Wash. Both of these systems empty into the Santa Cruz River and the IWWTP effluent is a potential source of water for a constructed wetland complex. Analysis of the SPMD sample extracts revealed the presence of organochlorine pesticides (OCs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). The bioindicator tests demonstrated increased liver enzyme activity, perturbation of neurotransmitter systems and potential endocrine disrupting effects (vitellogenin induction) in fish exposed to the extracts. With increasing global demands on limited water resources, the approach described herein provides an assessment paradigm applicable to determining the quality of water in a broad range of aquatic systems.

Chemosphere

Use of risk assessment to evaluate effects and plan remediation of abandoned mines

A framework of risk assessment is elaborated for the evaluation of the effects of abandoned mines and mills. Steps in this process include environmental description, identification and characterization of sources, assessment of exposure, assessment of effects, risk characterization, and risk management of remediation. The development and use of ecological end-points for remediation is discussed in terms of the chemical constituents, toxicity tests and the biological community.

Conference Paper