A vessel collision report for Bryde's whales (Balaenoptera brydei) off the northern coast of Sao Paulo, Brazil

Vessel collisions are an important threat to several cetacean species, both large and small. In addition to negatively affecting the animals themselves, collisions can also damage or sink vessels, threatening both human safety and marine industry economics.Larger cetaceans seem to be the most affected by vessel collisions, and vessel strikes with Bryde's whales (Balaenoptera brydei/Balaenoptera edeni) have been reported worldwide.Long-term photo-identification research on Bryde's whales off the northern coast of the state of Sao Paulo, Brazil, has been continuing since 2016. Of the 67 individuals that were photo-identified between 2004 and January 2022, three (4%) presented scars compatible with injuries from vessel propellers. These data contribute towards an understanding of the long-term effects of collision injuries on the behaviour and survival of Bryde's whales.This report is intended to help inform the future evaluation of the conservation status of B. brydei off Brazil.

Automated summary

Vessel collisions pose a significant threat to various species of cetaceans, including both large and small ones. In addition to harming the animals themselves, collisions can also cause damage or sinking of vessels, thereby endangering human safety and marine industry economics. Bryde's whales appear to be particularly vulnerable to vessel strikes, and cases of such collisions have been reported worldwide. Long-term photo-identification research conducted in Sao Paulo, Brazil since 2016 revealed that 4% of the 67 Bryde's whales identified between 2004 and January 2022 exhibited scars consistent with propeller injuries from vessel collisions. These findings contribute to understanding the long-term impacts of collision injuries on the behavior and survival of Bryde's whales. The report aims to support future assessments of the conservation status of B. brydei in Brazil.