Effects of vehicle traffic and trampling on the macrobenthic community of Amazonian macrotidal sandy beaches

Abstract

We report for the first time the effects of vehicle traffic and beachgoer trampling on macrobenthic communities of Amazonian sandy beaches. Sampling was performed during four consecutive months with different beach use intensity in 2017 (before, during vacation, and two months after the vacation period) on three contrasting beaches with regard to disturbance (Urban: Atalaia; Intermediate: Farol-Velho; and Protected: Corvinas) in the intertidal zone along two equidistant transects at seven equidistant sampling stations from the high-tide water mark to the swash zone. At each sampling station, four biological and sediment samples were randomly collected. Also, in each station, the sediment compaction was determined using a manual penetrometer. Physical sediment variables remained constant over time in all beaches, whereas differences were found in sediment compaction over the months. Macrobenthic community differences in density and richness among months were observed at Atalaia and Farol-Velho beaches. In contrast, Corvinas beach remained constant throughout the study period. Furthermore, the vulnerability of the polychaetes Thoracophellia papillata, Scolelepis squamata and Paraonis sp. indicates that they might be potential indicators of recreational activity impact.

Effects of the ridge‐and‐runnel system on macrofaunal spatial distribution on a macrotidal sandy beach in the Brazilian Amazon coast

“…The absence of D. striatus in the upper intertidal of area 1 (ST: B) contrasts with the presence of this bivalve in the same station of area 2. In addition, the presence of D. striatus at the upper intertidal stations (ST: A and B) on two Amazonian beaches without runnels (Santos et al, 2022) reinforces that these microhabitats are not favourable to this bivalve.…”

“…In addition, the polychaetes T . papillata , N. simoni and S. squamata , typical of Amazonian sandy beaches, also occurred in this area (Rosa Filho et al, 2009, 2011; Santos et al, 2021, 2022; Santos & Aviz, 2018, 2020).…”

“…The presence of these larvae throughout the mid-littoral might result from their transport during tidal movements. Insects were expected to be limited to parts of the upper mid-littoral, as occurred in the area of Corvina Beach without channels and as observed on other Amazonian beaches (Rosa Filho et al, 2009Santos et al, 2021Santos et al, , 2022.…”

“…and Cyprideis sp., which had high abundance in area 1, are also deposit feeders with higher affinity to muddy sediments (Angonesi, 2005;Dean, 2001;Lana, 1986;. In addition, the polychaetes T. papillata, N. simoni and S. squamata, typical of Amazonian sandy beaches, also occurred in this area (Rosa Filho et al, 2009Santos et al, 2021Santos et al, , 2022Santos & Aviz, 2018.…”

A simple method for species identification of the ghost crabs using PCR-RFLP

“…The presence of a top predator is indicative of the presence of many species in the food web (i.e., Paine 1988, Sergio et al 2005. In addition, they are vulnerable to anthropogenic disturbances such as trampling, vehicular traffic, and excessive beach cleaning on the sandy beaches (Barros 2000, Neves & Bemvenuti 2006, Wada 2017, Costa et al 2022, Santos et al 2022). Thus, biological monitoring of ghost crabs provides important information on the ecosystem health of sandy beaches and is useful in detecting symptoms of ecosystem change.…”