Multidisciplinary approach to a study of water and bottom sediment quality of streams associated with mixed land uses: Case study Del Gato Stream, La Plata (Argentina)

Abstract

Surface water bodies receive a basin's wide diversity of pollutants, especially when there are mixed land uses. Among the many environmental tools to assess a body water quality, most studies use only a few. In addition these studies, usually, are focused only on a set of pollutants and an environmental matrix. The Del Gato Stream a surface watercourse within of more populated area of Argentinaexemplifies the typically contrasting land uses around this area's streams. The predominant land uses along of the stream are agricultural in the upper, urban and industrial the middle, and animal husbandry in the lower subbasin. The aim of this study was to use a multidisciplinary approach to evaluate the environmental quality of that stream as a model of surface-water bodies within mixed-land-use regions in the Buenos-Aires metropolitan area. At each of the sampling sitesdistributed along the stream as follows: 3 in the upper, 4 in the middle, 3 in the lower subbasingeneral water parameters were measured; water and sediment samples taken for physical, chemical, microbiological, and ecotoxicological analysis; and the variables in each environmental matrix, analyzed separately and jointly. The stream presented a significant general deterioration, the middle subbasin with urban-industrial land use being the most impacted, where metals and metalloids recorded highest levels, and the rest of the measured parameters were also found at high levels. The upper subbasin had the highest quality, and the lower subbasin proved poor quality regarding microbiological variables, nutrients, and general water parameters. The tests included in the toxicity battery did not reflect a common pattern of toxicity along the watercourse. However, when they were integrated in the EDAR index, the middle subbasin was the most affected sector of the stream. Although, the usefulness of each analysis tool must be evaluated taking into account the objective of the study, if the aim is to know the general environmental quality of a stream, the multiple-factor analysis proved to be the most effective means in complex systems under the influence of great diversity of pollution sources. This study provides relevant information about the ecological quality of a stream representative of a region with scarce environmental information.

Fish Assemblages in Pampean Streams (Buenos Aires, Argentina): Relationship to Abiotic and Anthropic Variables

“…MI while C. decemmaculatus takes advantage of the higher dissolved oxygen concentration in the uppermost layer of the water without needing to alter its swimming posture as a result of an upward orientation of its mouth and a flattening of its head (Lewis 1970, Kramer & Mehegan 1981. Rimoldi et al (2018) reported mortalities of up to 60% for C. decemmaculatus in laboratory exposures to the urban El Gato Stream water. Furthermore, several other contaminants have been determined in the El Gato Stream, such as metals.…”

Horticulture affects macroinvertebrate assemblages in adjacent streams (Buenos Aires, Argentina)

“…The information on pesticide concentrations in horticulture watersheds is scarce (Kreuger et al, 2008;Allinson et al, 2014;Mottes et al, 2017). Only few studies have monitored the levels of those xenobiotic and the consequent toxicity to aquatic organisms in the La Plata horticultural belt (Mac Loughlin et al, 2017;Rimoldi et al, 2018). Solis et al (2018) compared the assemblage composition in streams influenced by agriculture or livestock and within a reserve.…”

Distribution, Source and Risk Assessment of Heavy Metal(oid)s in Water, Sediments, and Corbicula Fluminea of Xijiang River, China

“…The released metals/metalloids can pose serious and long-lasting threats to the environment due to the associated adverse health effect, environmental persistence, and bioaccumulation in biotas and human body. While trace amounts of metals/metalloids can originate from natural sources, such as weathering of rocks and minerals and volcanic activities, human activities account for the most input into the aquatic systems, including mining and mineral processing [5,6], metal smelting [7,8], domestic and industrial effluents [9,10], urban surface runoff [11,12], agriculture and animal husbandry activities [13,14], fossil fuel combustion and atmospheric depositions [15,16], and ship dumping [17].…”