We set out to understand how urbanization affects streams in Ushuaia, Tierra del Fuego. Paired ttests and linear regressions were used to compare physico-chemical stream habitat variables (i.e., temperature, turbidity, conductivity, dissolved oxygen and pH) and benthic macroinvertebrate community structure (i.e., density, taxonomic richness, Shannon-Weiner diversity) and function (functional feeding groups [FFG]) in four watersheds with urban and reference sites. We then calculated indices of biotic integrity for habitat (rapid visual assessment protocol [RVAP]) and benthos (Ephemeroptera, Plecoptera, Trichoptera richness [EPT], family biotic index [FBI], rapid bioassessment protocol [RBP] and biotic monitoring Patagonian streams [BMPS]). Results indicated that urbanization negatively impacted these streams' underlying ecological condition, decreasing benthic biodiversity and dissolved oxygen, while increasing conductivity and turbidity. FFG assemblage was similar between both sites, but urbanization increased the existing dominance of collector-gatherers. Additionally, urban sites presented lower values in three of the benthic macroinvertebrate indices (EPT, RBP, BMPS, but not FBI) and also for habitat (RVAP). These data fill an existing gap in stream ecology for southern Patagonia and are useful to create monitoring tools. By incorporating urbanization as a driver of ecosystem change, managers and planners will be better able to confront the issue of sustainable development in this region, which is considered one of the most pristine wilderness areas remaining on the planet but whose human population is concentrated in a few densely populated urban areas.
The last nine years have seen major change in the Mexican educational system as sweeping reforms across all levels have been implemented. In particular the early years of education have become the focus of legislation to increase quality, open access, and improve curriculum. How technology shaped these sweeping reform efforts will change the future of Mexico in a global community. Early childhood education must support the use of technology if the population is to move into a techno-society.
Wetlands in arid regions are characterized by their great heterogeneity, often including endemic species that contribute to regional aquatic biodiversity. In the Patagonian steppe, most lakes are naturally fishless and sustain a rich aquatic biodiversity, including endemics; however, many of these lakes have been stocked with Oncorhynchus mykiss (rainbow trout) during recent decades. The introduction of predatory fish into aquatic ecosystems naturally devoid of these organisms can produce profound alterations in the structure of the original communities and in the configuration of their biotic assemblages.
Aquatic invertebrates play important roles in both the structure and functioning of freshwater ecosystems, including their contribution to global biodiversity and their cascading effects across ecosystem boundaries.
The aim of this study was to assess the effect of introduced non‐native fish on the pleustonic macroinvertebrate assemblage. Samples were taken from 10 shallow Patagonian lakes (five fishless and five stocked with fish) in two consecutive warm periods.
Lakes with fish had higher conductivity and phosphate values. Higher inter‐annual differences were also observed in lakes with fish for phytoplanktonic chlorophyll a, nitrate, phosphate, conductivity, and water temperature.
The community structure (relative abundance of different taxa, species composition, and diversity index) was affected by the presence of rainbow trout, with the differences mainly driven by the relative abundance of Ostracoda, Hyalella, Chironomidae, and Haliplus species.
This approach can be used to assess the required conservation actions in shallow Patagonian steppe lakes, which have been listed as priority areas for waterbird conservation. Specifically, this study provides a baseline for monitoring future trends of the macroinvertebrate communities and for evaluating conservation and management efforts over time.
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