Sensitivity of macroinvertebrates to human impacts on sandy beaches: A case study with tiger beetles (Insecta, Cicindelidae)

Abstract

As with most sandy beach invertebrates, tiger beetles respond negatively to anthropogenic disturbances. However, impact assessments using these insects have never been conducted on tropical sandy beaches. The aim of the present study was to compare the sensitivity of tiger beetles to human impacts with other macroinvertebrates both locally and globally based on field collections and an extensive literature review. At the local scale, the abundance of Cylindera nivea (Kirby, 1818) was compared in the intertidal zone of six sandy beaches with distinct levels of human disturbances at two periods, in the low and high tourism seasons. The abundance of C. nivea was negatively (p < 0.001) related to the urbanization level, and no individuals were found on the high-impacted beaches even outside of the tourist season. Globally, tiger beetle species are usually absent from impacted areas, showing a higher sensitivity score (SH = 3.7) to human impacts compared to other beach macroinvertebrates (SH ≤ 3.2). Thus, we suggest using tiger beetles as indicator species for beach monitoring, relative to their abundance in non-impacted areas.