Cetaceans along the southeastern Brazilian coast: occurrence, distribution and niche inference at local scale

Giovanna Corrêa E Figueiredo; Karina Bohrer do Amaral; Marcos César de Oliveira Santos

doi:10.7717/peerj.10000

Cetaceans along the southeastern Brazilian coast: occurrence, distribution and niche inference at local scale

PeerJ. 2020 Oct 5:8:e10000. doi: 10.7717/peerj.10000. eCollection 2020.

Authors

Giovanna Corrêa E Figueiredo¹, Karina Bohrer do Amaral², Marcos César de Oliveira Santos¹

Affiliations

¹ Department of Biological Oceanography, Universidade de São Paulo, São Paulo, São Paulo, Brazil.
² Department of Zoology, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.

Abstract

It is deemed important to understand cetacean occurrence and distribution to comprehend their ecological roles. The geographical occurrence of species' niche can be used to better describe their potential distribution. The niche can be defined using environmental variables. Those variables are considered static and not affected by biological activities. The present study goal was to assess the occurrence and distribution of cetaceans along the southeastern Brazilian coast, as well as to define the fundamental and realized niche of each species and to investigate niche overlap at local scale. The environmental requirements for each species were also investigated throughout statistical tests. Sighting data were obtained through oceanographic surveys conducted between 2012 and 2015. The environmental variables available on MARSPEC and the software NicheA were used for the ecological niche modeling. A total of twelve cetacean species were identified and the potential distribution areas of the six commonest ones were defined. Even though the species presented different environmental preferences, most of them had partial overlap among niches and potential distribution areas. The environmental heterogeneity of the study area might support the co-occurrence of different species with different environmental requirements.

Keywords: Balaenoptera edeni; Ecological niche modeling; Niche overlap; Pontoporia blainvillei; Sotalia guianensis; Stenella frontalis; Steno bredanensis; Tursiops truncatus.

Grants and funding

This study was supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP process number 2011/51543-9). The survey at the Parque Estadual Marinho da Laje de Santos conducted between 2013 and 2015 was funded through an environmental license process issued by the Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis (IBAMA) in order to regulate the natural gas production and outflow system from the Campo de Merluza at Santos Basin under Petrobras responsibility (Process 02022.010930/2002-19). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.