Europe’s biggest aquarium faces legal action over the deaths of 30 hammerhead sharks, which a marine conservation group alleges were mistreated. Sea Shepherd France announced at the weekend that it would file a lawsuit on Monday against the Nausicaá aquarium in the French port of Boulogne, near Calais. The last of the 30 sharks, which were introduced into the aquarium in 2011 and 2018, died on Thursday.
Sea Shepherd accuses the aquarium of “serious mistreatment” of the sharks and “breaches of environmental law”.
Philippe Vallette, the manager of Nausicaá, rejected the allegations and the claim that they died because they were kept in captivity. He said the hammerheads died from “a fungus, latent in the organism of sharks, which spreads when they are in a weakened state”.
Mr Vallette said hammerheads were prone to fungal infection even in the wild. “A female has 600 to 700 young during her life and the survival rate of a hammerhead shark is one for every two or three hundred.”
But shark experts say hammerheads die earlier when placed in captivity. Nicolas Ziani, an ichthyologist, said their life expectancy decreased from 30 to about 12 years.
Hammerheads are an endangered species, notably because of the practice of ‘shark-finning’ in which their fins are removed. Unable to swim properly, they sink to the sea bottom and die. Fishing of hammerheads is regulated under the CITES international treaty.
Twenty of the sharks were transported to the aquarium after being captured off Australia in 2011. Last year Nausicaá bought another 10 baby sharks.
Many of the sharks, weakened by the fungal infection, reportedly attacked and killed each other.
Their deaths are hugely embarrassing for the aquarium, which has been known for protecting fish and marine animals and championing environmental causes for three decades. “We were the victims of our own ambitions,” Mr Vallette said.
The deaths also represent a major financial loss for Nausicaá, which opened a new basin for the hammerheads last year. The size of four Olympic swimming pools, it contains 600,000 litres of water and tries to recreate the ecosystem of the open sea.
It cost the aquarium more than £2 million to build the basin on the Channel coast, in addition to more than £1.3 million to capture and transport the sharks.
The scalloped hammerhead is one of the most difficult sharks to raise in captivity and Nausicaá has been accused by a French animal protection society, the Trente Millions d’Amis foundation, of “sacrificing animal lives for the sole purpose of entertaining the public”.
Mr Vallette said: “The purpose of keeping animals in captivity is so that researchers can observe their behaviour.”
In a statement, the aquarium said: “The presence of the hammerheads at Nausicaá was intended to make our visitors acquainted with the beatty and fragility of this animal, to get to know it better and observe its behaviour in order to learn to protect it better in its natural environment.”