In a first-of-its-kind experiment, researchers in Australia had the opportunity to tag a dead whale to see how the carcass moved through the ocean and where it fell to the seafloor.
With an increase in whale strandings in Australia, understanding how remains travel with ocean currents is important when making decisions about disposing of carcasses.
"As we’ve seen more and more whales stranding on Australian beaches in past years, the effective, safe and culturally sensitive removal of whale remains near or on public beaches has become a major issue,” says Olaf Meynecke, from Griffith University’s Whales and Climate Research Program, who led the study.
Current disposal methods, which include leaving the carcass on the beach, exploding it or sending it to landfill, can be difficult, expensive and pose public health risks.
In July 2023, they found a dead humpback whale floating off the coast of Noosa Heads, Queensland. The 14m female was probably killed by a ship strike. The researchers took this opportunity to test disposal at sea: a solution that could benefit the environment and members of the public.
Meynecke and his team moved the whale 18.5 miles (30km) offshore, added a satellite tag and tracked its location for six days until it fell to the seabed. This allowed them to develop and test a method to predict where the whale would drift with the wind and currents – a scientific first.
“Our study shows that forecasting of where whale remains might end up when floating at sea is possible with surprisingly high accuracy,” says Meynecke.
Whales that died from strandings have previously been towed out to deeper waters but some ended up in shipping lanes or back on shore. Being able to accurately predict where they will drift could give authorities a safe and cost-effective way of disposing of carcasses.
If a dead whale is returned to the ocean, it also benefits animals that feed on it – from tiger sharks to deep-sea scavengers – and returns its nutrients to the ocean.
“Strategically placing whale remains offshore can enhance nutrient cycling and foster biodiversity, contribute to carbon removal and marine floor enrichment for up to seven years,” says Meynecke.
There are lots of factors that should be considered when deciding how to handle whale remains, says Meynecke, but scientific research “can enhance our ability to predict and effectively manage the drift of whale remains, ensuring that ecological benefits are maximised while minimising adverse impacts.”
More about whales
