A juvenile humpback whale was found deceased after swimming approximately 11 kilometers upstream in the Clarence River on New South Wales’ mid-north coast, prompting authorities to issue a shark warning for nearby beaches. The whale was first spotted on Saturday afternoon near Bundjalung National Park and was later towed back out to sea on Sunday.

Officials from the NSW National Parks and Wildlife Service reported that the whale, which appeared sick, entered the river and became stranded on a sandbar in shallow water, where it died within 30 minutes. Following the incident, SharkSmart NSW advised the public to avoid activities such as swimming, surfing, and diving at surrounding beaches due to increased shark activity attracted by the whale carcass.

Marine biologist Dr. Vanessa Pirotta noted that while it is uncommon, humpback whales sometimes venture into rivers and estuaries. Such behavior may stem from curiosity, navigational error, or underlying health issues. In this case, the whale appeared “extremely unwell,” suggesting illness as a likely factor. Dr. Pirotta added that the timing was unusual since most humpbacks are currently migrating south toward Antarctica for feeding.

Similar incidents have been recorded in recent years along Australia’s east coast. In April, a whale became stranded on a sandbar in Wallis Lake, while in 2025, two humpbacks swam under Melbourne’s West Gate Bridge into the Yarra River. In 2020, three humpbacks entered the East Alligator River in Kakadu National Park, with one traveling 30 kilometers upstream before all eventually returned to open waters.

Although humpbacks can breathe air and survive temporarily in freshwater, prolonged exposure is harmful to their skin and overall health. Experts urge the public to report any sightings of whales or other marine mammals in unusual locations or distress to environmental authorities promptly.

A representative from the cetacean rescue organization Orrca emphasized that while it is rare for humpbacks to travel far into river systems, it is not unprecedented. The juvenile whale’s heavy covering of barnacles indicated it may have been suffering from a chronic illness or injury, though the exact cause of death could not be determined from visual observation alone.

Each year, around 50,000 humpback whales migrate along Australia’s east coast. Among such a large population, a small number are occasionally observed in poor condition or showing signs of health problems.

This recent event follows another involving a humpback whale carcass that washed ashore at Perth city beach less than a week prior, which attracted multiple sharks before being removed. Authorities and rescue groups remind the public to avoid entering waters near whale carcasses and to heed any local warnings due to the risk of shark encounters around scavenging sites.