The 4-metre (13-foot) orca, identified as a male, was first
spotted at the mouth of the Seine on May 16 between the port of Le Havre and
the town of Honfleur in Normandy, before it swam dozens of miles upstream to
reach west of the city of Rouen.
Following a meeting with national and international
scientists, including marine mammal specialists, the local prefecture tried on
Saturday to guide the whale back to the sea with a drone while emitting orca
But the whale responded “erratically” and
“incoherently” to the sound stimuli, the prefecture of the Seine
maritime area said in a statement. Sound recording of the whale captured what
they said was akin to distress calls by the animal.
“The attempt to bring back the whale to sea having
failed, and to prevent adding to it stress levels, a decision was made to stop
the intervention in the evening,” it said.
Scientists reviewed pictures and data from the intervention
and concluded that the animal was suffering from mucormycosis, or black fungus,
a disease seen in whales in North America but that had not been observed in
After infecting the skin of weakened animals, the disease
can spread to the heart, lungs and brain, which explained the whale’s
disorientated behaviour, the prefecture said. It added that the disease seemed
very advanced in this case and was probably causing the whale major suffering.
“In these conditions, the expert group concluded
unanimously that the only possible solution was to euthanise the animal to end
his suffering and, also, to carry out advanced analysis of the disease it is
carrying,” the prefecture added.
Experts from the French office for biodiversity (OFB) as
well as the Sea Shepherd NGO were among the specialists involved in the failed