Heroin substitute kills dolphins in zoo
Two dolphins died a slow, agonising death during a weekend-long rave at a Swiss zoo - after party-goers fed them a heroin substitute.
Blood tests showed the underwater mammals, Shadow and Chelmers, had been given recreational drug Buprenorphine by clubbers during the controversial event.
The tablets suppressed the dolphins’ natural instinct to come to the surface for air, causing them to drown.
It was originally believed the deafening techno music at the two-day dance event, held yards from the dolphins’ pool at Connyland marine park in Lipperswil, Switzerland, had caused their deaths last November.
But toxicology tests revealed they had been fed the drug, which is used to wean addicts off heroin.
Dutch marine biologist and dolphin expert Cornelis van Elk said: “Opiates are extremely dangerous for underwater mammals and would never be used in any legitimate treatment.
“The reason is that dolphins are conscious breathers, which means they actively decide when to come to the surface to breathe.
“Even when sleeping, there is part of the brain that automatically controls the breathing instinct in the same way as it does for people when asleep.
“Drugging them with opiates causes this part of the brain to switch off, with fatal consequences.”
Shadow and Chelmers were found after what experts described as a “drawn out and painful” death.
Connyland zookeeper Nadja Gasser said Shadow was found dead after the rave – and his companion soon started exhibiting strange behaviour.
She said: “When we went to start the dolphin training we noticed the same thing that had happened to Shadow was happening with Chelmers.
“He was drifting under the water and was clearly in trouble and so we jumped into the water. We tried to hold him. He was shaking all over and was foaming at the mouth.
“Eventually we got him out of the water. His tongue was hanging out. He could hardly breathe. He was given adrenalin, but it didn’t help.
“The death went on for over an hour. It was horrendous. I have not been able to sleep since.”
Furious animal activists say they warned both the marine park and local planners who gave permission for the rave of the dangers before the event.
They had been concerned that the high levels of noise could damage the marine mammals’ sensitive sonar and hearing and harm their delicate immune system.
Connyland has consistently denied any wrongdoing.