Urban streams in Latin America: Current conditions and research needs

Abstract

Introduction: Latin America is a highly urbanized region, with most of its population living in cities and urban centers. While information about urban streams in Latin America is rather limited, streams are expected to experience similar environmental impacts and conservation issues as urban streams in parts of the globe, including habitat loss, channelization, sewage discharge, trash, and loss of riparian habitats. Objective: We surveyed a network of researchers from approximately 80% of the countries in Latin America to obtain information on the condition, state of knowledge, and threats to urban streams in the region. Methods: Most participants were reached via the Macrolatinos@ network (www.macrolatinos.net). Results: We obtained 104 responses from researchers in 18 of the 23 Latin American countries. Most urban streams are impacted or degraded, and inputs of contaminants and wastewater discharges were considered major drivers of stream degradation. Most respondents indicated that stream channelization is common, with some streams completely channelized or buried. Sewage and rainfall runoff management were identified as a major factor degrading streams, with most respondents suggesting that streams are a primary destination for wastewater discharge, much of which is untreated. Major limitations to urban stream conservation in Latin America are the result of limited ecological knowledge, lack of citizen interest or political will to protect them. There are isolated efforts to restore urban streams and riparian zones, but these are initial steps that need further development. Conclusions: Our research network of Latin American scientists proved to be a valuable tool to assess a large number of urban rivers in a relatively understudied region. Urban streams in Latin America face a diversity of stressors and management challenges, and we propose three areas that would benefit from further research to improve our understanding and management of these systems: (1) Studies should focus on the watershed, rather than isolated reaches, (2) researchers should strive to attain a better understanding of ecosystem function and the services provided by urban streams to justify management and restoration efforts, and (3) studies that integrate economic models where downstream users pay for upstream protection and restoration could prove beneficial for many Latin American cities in attempting to address water conservation issues.

Aquatic macroinvertebrate trophic guilds, functional feeding groups, and water quality of an andean urban river

“…Changes in environmental variables affect organism assemblages, as is the case of macroinvertebrates in the present study, reducing the diversity, richness, and abundance of most taxa (except for the most tolerant taxa) (Correa-Araneda et al, 2010;Piano et al, 2020;Walteros and Ramírez, 2020). This effect was also reflected in the values of the indices estimated from the information obtained.…”

Systematic challenges and opportunities in insect monitoring: a Global South perspective

“…South America, home to diverse ecosystems like the Amazon Basin and páramos, confronts threats from urbanization, mining, agriculture and deforestation [ 29 ]. In Latin America, the fastest urbanizing region of the world [ 30 ], where urban population has surpassed rural since the 1980s [ 24 ], inadequate urban planning and sanitation practices (common direct disposal of sewage into natural waterways in the area, [ 31 ]) pose significant risks to both human populations and ecosystems supporting rich insect diversity [ 32 ]. Colombia, despite overcoming internal conflict, faces challenges in biodiversity exploration.…”

From the Forest to the City: the Arrival of Dragonflies and Damselflies to the Urban Jungle

“…The massive growth of urbanization has driven one of the most substantial transformations in water bodies among other habitats for a number of reasons (Goertzen and Suhling, 2019;Johansson et al, 2019;Meland et al, 2019). In general, urban streams are subjected to toxins, temperature change, siltation, organic pollutants, and the replacement of riparian vegetation for concrete, which limits rainfall in ltration, modi es ow regimes and increases runoff and ooding risk (Bogan et al, 2020;Walteros and Ramírez, 2020).…”