Occurrence of blue whales (Balaenoptera musculus) in offshore waters of southeastern Brazil

Abstract

At-sea sightings of blue whales, Balaenoptera musculus, in Brazil are rare. A mother-calf pair was observed in deep (2645 m) waters off southeastern Brazil (22°11′S 038°58′W); during a seismic survey in July 2014. It is unknown to which of the subspecies the animals sighted belong. The presence of a calf suggests that blue whales use deep waters off Brazil as calving or nursing grounds. The identification and conservation of wintering grounds for blue whale populations is important to promote the recovery of blue whales as their numbers were critically reduced as a result of commercial whaling.

A NORTHERN RECORD OF PANTROPICAL SPOTTED DOLPHINS (Stenella attenuata) IN SOUTHWEST ATLANTIC OCEAN

“…The scarcity of sightings of cetaceans in SWA is due to a combination of factors, including the limited cetacean-oriented survey efforts in deep waters along the Brazilian coast (Di Tullio et al, 2016;Rocha et al, 2019). Hence, most of the studies concerning the occurrence of such marine mammals in this area is based on a few localized records of strandings, accidental captures and opportunistic sightings (Rocha et al, 2019) and, so, the report of new occurrences, mainly in offshore waters, is extremely valuable to understand the distribution of cetacean species in this region.…”

“…Further studies in offshore waters along the Brazilian coast are essential for a better understanding of cetacean ecology and to confirm species distribution represented in coarse-scale maps, which are mostly represented by generalizations based on cumulative knowledge about their distribution over time, and, more recently, predicted through ecological modeling (Amaral et al, 2015;Rocha et al, 2019). Such surveys would not only Lívio Moreira de Gurjão provide a more complete description of the distribution pattern of Stenella dolphins in SWA but also might fulfill gaps on the occurrence of certain still unreported species in sites where they are suitable to be found, technically supporting ecosystem-based conservation initiatives in the region (IWC, 2016;Soares & Lucas, 2018;Giglio et al, 2018).…”

Report of the Scientific Committee

“…Other potential Antarctic blue whale wintering grounds include the greater Galápagos region (acoustic detections, Stafford et al, 2004), offshore South Africa, Namibia and Angola based (historical catches, Best, 1994), the Lau Basin off Tonga and Samoa (Balcazar et al, 2017) and recent sighting reports from Brazil (Fábio Daura Jorge, pers comm. ; Rocha et al (2019). Most locations are sufficiently remote to make surveys logistically challenging, and in some areas (e.g.…”