Occurrence and anthropogenic-derived mortality of humpback whales (Megaptera novaeangliae) along the northern coast of Argentina, 2003–2021

ABSTRACT

Sightings and strandings of humpback whales (Megaptera novaeangliae) along the coast of Buenos Aires Province in Argentina were once sporadic but have increased by up to 640% since 2018. Here, we assess the trends and seasonality of occurrence and anthropogenic-derived mortality in this population between 2003 and 2021. Most of the humpback whales found dead were young animals, and 27% of the stranded whales showed signs of anthropogenic interactions. The information collected from Buenos Aires Province over the past two decades clearly indicates that humpback whales are becoming more frequent and growing in numbers along the Argentinean coast. For their protection, governmental regulations need to be implemented as soon as possible.

KEYWORDS:

• Humpback whale
• Argentina
• strandings
• fishery interactions
• vessel strike
• sightings

Acknowledgements

The authors are very grateful to Prefectura Naval Argentina (National Coast Guard), marine mammal trainers, technicians and professionals from the Rescue and Rehabilitation Center of Mundo Marino Foundation and Mar del Plata Aquarium, and lifeguards from Mar del Plata and Necochea, especially Federico García Canales and his team. The authors also thank Faro Querandí rangers (Carolina Faivre and Abel Escobar); Lic. Analía Belaus (Coordinator of Claromecó Node of ECOFAM and part of COA Tres Cauquene); the ranger Juan Gasverde (Secretaría de Gestión Ambiental de Tres Arroyos) and ECOFAM volunteers, especially Ricardo Doumeq and Otto Bross from Necochea; Martín Bruno (Consorcio de Gestión Puerto Quequén); Sergio Lucero and Matías Olmos (del Museo Argentino de Ciencias Naturales (MACN)); marine mammal volunteers from our laboratory, Mesa de trabajo de Ballenas Mar del Plata; Karina Arias (Estación Hidrobiológica de Puerto Quequén, MACN-CONICET), Guillermo Collini (Organismo Provincial de Desarrollo Sustentable, Gobierno de la Provincia de Buenos Aires (OPDS)) and Pablo Celli (Piscicultura Necochea); Fundación Ecológica Pinamar; and staff from Mar Chiquita Natural Reserve. Thanks also to Dr Simon Elwen, Dr Katharina J. Peters, Dr Amanda Todd and anonymous reviewers for their great and useful comments and English edition.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Stranded whale (#19) entangled in a fishing net rescued by Fundacion Mundo Marino rescuers in August 2018. http://prez.ly/HFM.

Additional information

Funding

This work was funded by many projects of Universidad Nacional de Mar del Plata, ANPCyT and CONICET and also by Fundacion Mundo Marino, Agencia Nacional de Promoción de la Investigación, el Desarrollo Tecnológico y la Innovación.