Effects of human presence on reef fish interspecific interactions: influence of visitation levels and reef complexity in tropical and subtropical reefs

Abstract

Recreational diving has been growing in the last decades, becoming one of the most popular recreational uses of the marine environment. The activity provides an important source of income for coastal communities and to the management of marine protected areas. The damage caused to benthic sessile organisms by recreational diving has been a matter of worldwide concern. However, the effects of human presence on interspecific interactions remain poorly known. Through this proposal, we hope to advance the knowledge on how diver presence affects reef fish assemblages on both tropical coral reefs and subtropical rocky reefs. Results of this project will support management initiatives aiming to mitigate the impacts of recreational diving on reef fish and consequently ecosystem dynamics. In addition to the experimental sampling comparing visited reefs in both hemispheres, in this proposal, the post-doc intend to improve his analytical skills by conducting data analyses in collaboration with Dr. Elizabeth Madin. For more than a decade, Dr. Madin research has been focused on the intersection of human impacts and animal behaviour and how this can lead to cascading effects through food webs in marine habitats, while Dr. Pereira-Filho has been dedicated to identifying environmental drivers of benthic diversity in South Atlantic Reefs. For 5 years, the Laboratório de Ecologia e Conservação Marinha da Unifesp (LABECMar) has been spending efforts to monitoring benthic and reef fish assemblages of Alcatrazes Wildlife Refuge. The data was collected using the before-after control-impact approach, before and after the area be allowed to diving visits. This proposal will concatenate the background of the supervisors and lab members in advanced statistics and studies investigating spatial ecology and human effects on reef environments and fishes. This opportunity will be determinant to improve the skills of the post-doc in these topics and the quality of the manuscripts. During the BEPE, the postdoc intends to write two manuscripts integrating the Hawaiian and Brazilian datasets. Finally, it is important mention that during the #2017/22273-0 grant execution, Dr. Giglio has already authored six scientific papers and three scientific communication issues related with the grant topic.