Short-term effects of visitor trampling on macroinvertebrates in karst streams in an ecotourism region

Abstract

In order to evaluate the potential risks of human visitation on macroinvertebrate communities in streams, we investigated the effect of trampling using two short-term experiments conducted in a Brazilian ecotourism karst region. We asked three questions: (a) Does trampling increase the drift rate of aquatic macroinvertebrates and organic matter? (b) Does trampling change the macroinvertebrate community organization? (c) If trampling alters the community structure, is a short time (5 days, a between weekends interval - peaks of tourism activities) sufficient for community restructuring? Analysis of variance of richness, total abundance, abundance of the most abundant genus (e.g., Simothraulopsis and Callibaetis), and community composition showed that trampling immediately affects macroinvertebrate community and that the intervals between the peaks of visitation (5 days) are not sufficient to complete community restructuring. Considering that bathing areas receive thousands of visitors every year and that intervals of time without visitation are nearly nonexistent, we suspect that the negative effects on the macroinvertebrate community occur in a cumulative way. Finally, we discuss some simple procedures that could potentially be used for reducing trampling impacts in lotic environments.

Watch your step: insect mortality on hiking trails

“…In the case of threatened or endangered species that typically do not have large adult populations, fast reproduction rates or rapid recolonisation rates, mortality induced by human activities is likely to have significant population consequences (Escarpinati et al, 2014;Baxter-Gilbert et al, 2015). Moreover, insects are usually small and difficult to detect, so the number of trail-killed insects may well be underestimated.…”

“…sandy beaches, coastal dunes, karst streams) may lead to far-reaching changes in habitats occupied by invertebrates (Gheskiere et al, 2005;Comor et al, 2008;Escarpinati et al, 2014). sandy beaches, coastal dunes, karst streams) may lead to far-reaching changes in habitats occupied by invertebrates (Gheskiere et al, 2005;Comor et al, 2008;Escarpinati et al, 2014).…”

“…Frequent visits to places which people find attractive (e.g. sandy beaches, coastal dunes, karst streams) may lead to far-reaching changes in habitats occupied by invertebrates (Gheskiere et al, 2005;Comor et al, 2008;Escarpinati et al, 2014). The negative impact of tourists' activities may be due to direct causes such as active physical pursuits on trails, the destruction of habitats/vegetation adjacent to trails, the trampling of 'shortcuts' in places not intended for use by hikers, the large amounts of rubbish left alongside trails and near mountain hostels and the burning of leaf litter in unauthorised places.…”

Effects of Student-Induced Trampling on Aquatic Macroinvertebrates in Agricultural Headwater Streams

“…Trampling due to human recreational use of natural areas is a distinct form of anthropogenic disturbance and one that has become the focus of research in recent years. For instance, experimental simulations of trampling on stream macroinvertebrates in Australia and Brazil indicated that changes in macroinvertebrate taxa composition and declines in taxa richness and abundance occurred immediately after trampling [13,14]. These experimental simulations also indicated that it would take more than five days for macroinvertebrate community structure to recover from trampling [13,14].…”

“…For instance, experimental simulations of trampling on stream macroinvertebrates in Australia and Brazil indicated that changes in macroinvertebrate taxa composition and declines in taxa richness and abundance occurred immediately after trampling [13,14]. These experimental simulations also indicated that it would take more than five days for macroinvertebrate community structure to recover from trampling [13,14]. Field studies evaluating the impacts of instream hiking (i.e., trampling throughout the stream, typically upstream and downstream) and stream crossings (i.e., cross-channel trampling) by hikers, horseback riders and other recreationists in the United States have documented mixed macroinvertebrate responses.…”