Ocean warming is changing the migratory habits of these predators, which are now more prevalent near the Australian coast.
A recent study reveals that bull sharks are significantly extending their stay off Sydney’s beaches. These normally migratory animals traditionally left the region when sea temperatures dropped below 19°C in winter, preferring the warmer waters of Queensland. Acoustic data collected over fifteen years from 92 tagged specimens now show an extension of their summer presence by approximately two weeks compared to 2009.
The researchers highlight the potential implications of this change. Increased use of these predators near swimming areas could alter interactions with human activities. Although attacks remain rare in Australia, this species is one of the three responsible for the majority of serious incidents, alongside great whites and tiger sharks.
Furthermore, climate change appears to be influencing the reproductive cycles of these animals. Preliminary observations indicate the appearance of juveniles in southern rivers, an unusual phenomenon. At the same time, great white sharks, attracted to cold waters, are seeing their summering grounds shrink in northern New South Wales and Queensland. These ecological upheavals could eventually lead to a permanent presence of bull sharks in Sydney waters.
Animals
