Four decades of pinniped records on the coast of São Paulo state, Southeastern Brazil (1981–2023)

Authors

  • Renata Balsamo Dias Instituto de Pesquisas Cananéia (IPeC)
  • Camila Carvalho de Carvalho Associação de Pesquisa e Preservação de Ecossistemas Aquáticos (AQUASIS)
  • Renan Costa de Lima Laboratório de Ecologia da Megafauna Marinha (ECOMEGA)
  • Henrique Chupil Instituto de Pesquisas Cananéia (IPeC)
  • Fernando Siqueira Alvarenga Mineral Engenharia e Meio Ambiente
  • Andrea Maranho GREMAR
  • Rosane Fernanda Farah GREMAR
  • Carolina Pacheco Bertozzi Instituto de Biociências, Universidade Estadual Paulista
  • Carla Beatriz Barbosa Instituto Argonauta para a Conservação Costeira e Marinha
  • Hugo Gallo Neto Aquário de Ubatuba

DOI:

https://doi.org/10.5597/lajam00357

Abstract

Beach monitoring is an essential method for documenting marine mammal strandings, and gathering valuable information on individual and population dynamics. This study reports occurrences of pinniped strandings along the coast of São Paulo state (23-25° S), Southeastern Brazil, with the aim of updating species records, analyzing seasonal, annual, and spatial stranding patterns and identifying the sex and maturity class of the individuals. Data were collected between 1980 and 2023, initially through sporadic records and non-systematic monitoring. From 2015 onward, data were systematically collected via daily monitoring conducted by the Santos Basin Beach Monitoring Project (PMP-BS). Throughout the study period, a total of seven species were recorded in the state, representing both the Otariidae and Phocidae families: South American sea lion (Otaria flavescens), South American fur seal (Arctocephalus australis), Subantarctic fur seal (Arctocephalus tropicalis), Antarctic fur seal (Arctocephalus gazella), southern elephant seal (Mirounga leonina), leopard seal (Hydrurga leptonyx), and crabeater seal (Lobodon carcinophaga). The findings revealed that immature males of South American fur seal and mature males of Subantarctic fur seal were the most frequently encountered individuals. Strandings occurred year-round, with the highest number of occurrences observed in winter, the only season during which all listed species were recorded. Furthermore, the southern coast of São Paulo state exhibited the highest concentration of strandings. This study represents the first detailed account of pinniped records along the São Paulo coast.

A pod of four orcas surface close to shore in the Gulf of California, Mexico.

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Published

2025-10-31

How to Cite

Balsamo Dias, R., Carvalho de Carvalho , C., Costa de Lima, R., Chupil, H., Siqueira Alvarenga, F., Maranho, A., Farah, R. F., Pacheco Bertozzi, C., Barbosa, C. B., & Gallo Neto, H. . (2025). Four decades of pinniped records on the coast of São Paulo state, Southeastern Brazil (1981–2023). Latin American Journal of Aquatic Mammals, 20(2), 103-113. https://doi.org/10.5597/lajam00357

Issue

Vol. 20 No. 2 (2025)

Section

Articles

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