A pair of humpback whales were observed traveling between Australia’s eastern shores and breeding grounds in Brazil, according to research published on Wednesday. The findings reveal that these journeys represent the longest ever recorded for this species.
One whale was first spotted off Queensland in 2007 before reappearing near Sao Paulo in 2019 – a distance of approximately 8,823 miles across oceans. Another was seen off the coast of Bahia in Brazil and then sighted 22 years later in Hervey Bay, Australia, about 9,383 miles away.
These movements, while rare, are significant for maintaining genetic diversity within whale populations and potentially spreading new song styles between regions, researchers noted. The study utilized nearly 20,000 photos from both eastern Australia and Latin America over four decades to identify these whales.
The research underscores the importance of citizen science in such studies, with every photo contributing valuable data about whale biology. Additionally, it supports a theory known as the “Southern Ocean Exchange,” which suggests humpback whales sometimes travel to Antarctic feeding grounds but then return via a different route to new breeding areas. This could be due to climate-driven changes affecting their habitat and prey distribution.
Currently, four of the 14 distinct population segments of humpback whales are listed as endangered by NOAA, with one classified as threatened. Commercial whaling had led to this decline, although a moratorium on commercial whaling was established in 1985.