An ocean conservation group said Monday it had filed suit against a French aquarium over the premature deaths of 30 endangered hammerhead sharks.
The move came after the Nausicaa aquarium in the northern French port city of Boulogne-sur-Mer said on Thursday that its last hammerhead, acquired in Australian waters eight years ago, had died from a fungus infection.
It had stopped feeding three weeks earlier and been placed under observation.
The shark died from the same fungus that caused the deaths of 29 other hammerheads at the aquarium since it acquired and began exhibiting them in 2011.
Nausicaa, which bills itself as the largest public aquarium in Europe, said it was still investigating the causes for the early deaths of a shark that scientists say can live 20 to 30 years in the wild.
But the international non-profit group Sea Shepherd on Monday called for an investigation into the techniques used to obtain the sharks and the conditions of their captivity.
"Only greed, coupled with incompetence and flagrant irresponsibility, can explain this slaughter," it said.
The distinctive shark, which can reach four metres in length, is on the Red List of endangered species at the International Union for Conservation of Nature.
Nausicaa has defended its collection of the hammerheads, saying it is vital for protecting an animal at high risk of extinction.
"100 million (sharks) are killed each year for their fins," which are a prized delicacy in much of Asia, aquarium director Philippe Vallette said last week.
"If we want to increase our knowledge, we have to be able to observe them 24 hours a day. You can't do that in the ocean," he said.
The claim was dismissed by Sea Shepherd, which called on the authorities to investigate a site that gets millions of euros in public funding.
"If Nausicaa really wants to help protect the hammerhead... the three million euros of public funds spent on this project should have been invested in the fight against poaching," it said.