Macroinvertebrates as indicators of human disturbances on sandy beaches: A global review

Published in Ecological Indicators,118, 106764
Authors

Costa, L., Zalmon, I., Fanini, L., & Defeo, O.
Publication year 2020
DOI https://doi.org/10.1016/j.ecolind.2020.106764
Affiliations
  • Universidade Estadual do Norte Fluminense Darcy Ribeiro, Laboratório de Ciências Ambientais, Campos dos Goytacazes, Brazil
  • Hellenic Centre for Marine Research, Institute of Marine Biology, Biotechnology and Aquaculture (IMBBC), Heraklion, Greece
  • Facultad de Ciencias, Unidad de Ciencias del Mar. Montevideo, Uruguay
IAI Program
  • SMALL GRANTS PROGRAM: THE ROLE OF ECOSYSTEM SERVICES IN ADAPTATION TO GLOBAL CHANGE FOR HUMAN WELLBEING (SGP-HW)
IAI Project 1645887
Keywords
Bioindicator
Biomonitor
Ecological indicator
Human impact
Invertebrates
Monitoring
Meta-analysis

Highlights

  • The use of beach macroinvertebrates as indicators of human impacts was reviewed.
  • Response ratios of multiple metrics to disturbances were applied on a global scale.
  • Single-species responses performed better than aggregate descriptors in detecting impacts.
  • Reliable response ratios to specific impacts was difficult to reveal by single taxa.
  • Impact assessments must rely on the use of several indicator species and metrics.

Abstract

Sandy beaches are ecosystems under increasing human pressure that require efficient management and conservation strategies. Resident macroinvertebrates usually respond to disturbances by changing their behaviour and abundance, and therefore they may be used as indicator species using simple and low-cost monitoring strategies. We synthesize information from the scientific literature on the use of sandy beach macroinvertebrates as indicators of human disturbances operating at local scales. Response ratios were applied to perform a meta-analysis supported by empirical data to objectively assess the magnitude of human disturbances on beach fauna. The &ldquocompare and contrast&rdquo approach represented some 80% of the studies. Gradient assessments were performed by 16% of the studies, though without determining thresholds of disturbance. Long-term monitoring (encompassing more than two years) was the general approach used in studies about harvesting, but it was not used when assessing other type of disturbances. Causality relationships and mechanisms underlying impacts were rarely assessed. Useful indicators to specific human disturbances were: 1) ghost crabs, which indicate the negative effects of vehicle traffic and nourishment 2) talitrids as indicators of trampling and mechanical cleaning and 3) clams as indicators of harvesting. As beaches are affected by multiple stressors acting simultaneously, the relative importance of each one has been difficult to reveal. It remains a priority to identify how different human disturbances are affecting macroinvertebrates under a range of diffuse impacts. Such results would allow for the depiction of patterns and future studies should prioritize gradient analyses and manipulative experiments to provide thresholds of specific stressors and mechanisms of impacts.