Issues to consider when sampling the sandhopper Atlantorchestoidea brasiliensis (Dana, 1853) for impact assessments on sandy beaches

ABSTRACT

Pitfalls can trap mobile fauna during their peak surface activity, whereas sediment corer efficiently capture individuals buried in the substrate. Corer sampling is the most used method to capture the sandhopper Atlantorchestoidea brasiliensis, because of the assumption that bias related to surface activity during daylight can be controlled by a careful sampling. The objective of the present study was to evaluate the efficiency of pitfalls to sample the sandhopper A. brasiliensis on sandy beaches with distinct impact levels. We compared our results with a previous impact assessment on the same beach arc that used corer sampling. The sandhopper abundance was more than 10 times higher in the pitfalls compared to the corer samples, suggesting prevalent activity on the sediment surface during daylight and possible bias when using corer sampling to estimate population size. The conclusion of the previous impact assessment, however, was not strongly affected by sampling tools, because seasonal trampling seems to be negative for the number of buried and surface-active individuals. Our results showed that the choice of sampling tool is an important issue to be considered when using sandhoppers as indicator species on sandy beaches.

KEYWORDS:

• Corer
• indicator species
• pitfall
• sampling tool
• Talitridae
• trampling

Acknowledgements

The authors thank Marcela Costa Silva Lombardi for the support during the field survey and the Laboratory of Environmental Sciences for the logistical support and Phillipe Mota Machado and Marjorie Cremonez Suciu for providing the dataset from 2012 to 2016.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Leonardo Lopes Costa http://orcid.org/0000-0003-2318-3543

Additional information

Funding

This work was supported by the Research Foundation of Rio de Janeiro – FAPERJ under grant E-26/111.395/2012, Brazilian Agency for Research Development – CNPq under grant 470142/2013-8. Costa, L.L was supported by the Research Foundation of Rio de Janeiro – FAPERJ (E-26/200.813/2019); Conselho Nacional de Desenvolvimento Científico e Tecnológico; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior; Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro.