The three bottle-nosed dolphins Nando, Rocco and Palawas will be re-housed – ideally somewhere in Europe – by the end of the year.
The closure announcement was celebrated by animal rights activists who have often criticised Münster zoo for the enclosure being too small.
“We would have needed 20 to 30 million litres of water, instead of the two or three million litres we have in the tank now,” said dolphinarium head Henk Hidding.
An outdated chorination system has contributed to eye problems and eczema suffered by the dolphins, a whale and dolphin protection group has consistently claimed.
“We would have needed €20 million in order to bring the enclosure up to scratch,” said Münster zoo director Jörg Adler. “Either we keep the dolphins in most modern conditions possible, or not at all,” he added.
The closure – scheduled for this autumn – will leave just two places in Germany keeping dolphins in captivity.
And although the dolphins have long been popular with visitors to the zoo, a survey showed that most of them would prefer to see no dolphins at all as opposed to those kept in sub-standard conditions.
Jürgen Ortmüller, head of the cetacean protection group WDSF, said the closure was due to, “years of persuading from the WDSF and not the supposedly responsible actions of the zoo's management.”
He said inappropriate medical care has regularly contributed to ill health among the animals.
The oldest of the Münster trio, Nando, is 22, elderly for a dolphin. His two friends Palawas and Rocco are eight and nine respectively, a Münster zoo spokeswoman told The Local.
Responsibility for entertaining visitors will now fall to the sea lions, which are said to be cheaper and easier to keep.
By the end of the year, Duisburg and Nuremberg will be the last remaining German zoos with captive dolphins but they, like Münster, have been the target of animal rights campaigners.
Nearly 100 of the animals have died since they both opened.
“Dolphins do not belong in captivity,” said Ortmüller, adding that the group were working on getting all dolphins removed from Germany's zoos.
“Our next targets are the enclosures in Duisburg and Nuremberg,” he confirmed.