WSP05781 - Laserfiche WebLink

Home Browse Search

3. Methods This review was organized mainly by contaminant source, as sources primarily defme the more substantial studies discussed herein. The RESULTS section begins with background information concerning San Juan River fish, disease, and standards, that is important to understanding the discussions that follow. Background information is included elsewhere in the RESULTS section where pertinent. Raw data from studies are generally located in a separately bound volume of appendices 01 illume II, Appendices 4-16), while discussion of the data is found in the body of this review under RESULTS. The review attempts to give a reader who has little or no prior knowledge of contaminants the tools necessary for a basic evaluation of the data that have been included. Few studies have collected data from the entire San Juan basin, with the vast majority of research stopping at state boundaries. An attempt was made to obtain parallel information for each of the three states, but in many cases this was not possible; therefore, the quality of information varies for a given category and in some instances was not available for one or more states. Additionally, little information was available for the Indian reservations. As the pwpose of the report was to identifY gaps in information, these discontinuities are only a problem insomuch as it makes an overall evaluation of the basin difficult for a given contaminant or contaminant source. Maps were included liberally in this review to facilitate evalul\tion of where geographic gaps in data exist. An attempt was made to convert units of measurement to standard forms to simplifY the comparison of data, but in many cases such conversions were not possible. For example, tissue sample analyses measure the concentrations of contaminants in either wet or dry weight, but to convert one to the other involves the use of a mathematical formula which requires the percent moisture of the samples. The percent moisture of samples is often not collected at the analytical laboratory, and when collected it is usually not included in the data set. Additionally, some older reports do not specifY the type of measurement; in these cases, the data were selectively included. To facilitate other data comparisons, a conversion table listing the concentrations of various unit measurements has been provided (Appendix 3). Within the text, conversions have been supplied.between English and metric units. The number given first is that which appeared in the reference cited; the number in parentheses is the conversion. Similarly, when available, both common and scientific names are given for species. The first time a species is mentioned its scientific name is given in parenthesis, and thereafter only the common name is used. Because surface water quality is a function not only of direct inputs but also of groundwater, soils, and even air quality, the volume of information regarding the basin is quite large. Therefore, for this review it was necessary to prioritize information according to its potential importance to San Juan basin native fishes. The highest priority was given to water quality, sediment, and biota studies from the San Juan River and its tributaries. Secondary priority was assigned to groundwater and soils if there was evidence that they affected surface water quality in the river or its tributaries. Studies on reservoirs were considered accordingto their applicability to San Juan basin water quality. Proposed projects such as the Animas-La Plata Project, although as yet undeveloped, received fairly high priority because of the magnitude of their potential effects on the basin's water quality. More recent information was given priority over older documents, but in many cases the only available information was a decade or more old. If the information was not obviously outdated, it was incorporated into the review. Conversely, only the most recent water quality data were included based on the assumption that older information would not normally be pertinent to the health of present-day fish populations. Research for this review has made use of as many types of documents as possible. Using CD- ROMs, the federal government documents depository at UNM was searched for pertinent items, while the general library holdings were used to provide background information on various topics. The depository contained only published documents, but there was also a wealth of unpublished information on contaminants and water quality. For this information, government agencies were visited and, where possible, unpublished data and communications were obtained for use in this review. These agencies included the Bureau of Indian Affairs, Farmington; Bureau of Reclamation, Durango; and Fish and Wildlife Service Ecological Services in Albuquerque, Grand Junction, and Salt Lake City. Other offices, 14