A Sub-tropical mass of water, driven by stream and prevailing winds...
Au revoir 'Osbourne'
Under the direction of Dr. Ian Walker and with the help of Dr. Neil Burnie, a joint crew from the Bermuda Aquarium, Museum & Zoo and the Bermuda Shark Project, "Osbourne" the Galapagos shark, a resident of the North Rock Tank at the BAMZ, was successfully released back into the wild.
by Owain Johnston-Barnes
published in The Royal Gazette 20 March 2012
Osbourne the shark went from the North Rock Exhibit to North Rock itself as he was released into the wild.
The seven-year-old Galapagos shark has been one of the showpieces of the North Rock tank for the last six years, but principle curator Dr Ian Walker said the shark had issues with one of the tank's other residents, a black grouper.
As a result of the conflict, Osbourne developed a rubbed rostrum (nose).
Staff at the Bermuda Aquarium Museum and Zoo worked to reduce aggression between the pair by using various training techniques, changing Osbourne's swimming pattern using buoys and using a red circle to indicate where the shark would be fed, keeping the pair separate at feeding time.
Dr Ian Walker, Principle Curator of the Aquarium, said: “Animal training is fairly complex and best done through positive feedback or rewards for performing the wanted behaviour. Complex behaviours are build up through a series of small steps that slowly move the animal towards the intended goal.”
BAMZ had planned to release Osbourne this summer, but plans were moved forward when aggression between the pair increased two weeks ago and the shark's health began to deteriorate.
“The decision to relocate the shark was not made lightly as sharks need to constantly have water flowing over their gills and can go into shock from stress relatively easily,” Dr Walker said.
On Friday morning, Osbourne was carefully lifted from the tank and carried in a specially made sling into a fast boat, with the assistance of Dr Neil Burnie and Choy Aming from the Bermuda Shark Project.
On the boat, Osbourne was placed into a shark transport box, where he had water pumped over his gills as he was held upside down in a relaxed state known as tonic immobility.
He was released over the side of the boat at North Rock, around seven miles off the Island's north shore while aquarist Steve Davis and Dr Burnie watched it swim away.
While Osbourne is no longer on display, Dr Walker said eyes will remain on him.
“Osbourne was released with a satellite telemetry tag, donated by the Atlantic Conservation Partnership, which will provide us with very useful information on his swimming patterns and to some extent his well-being,” Dr Walker said.
“We wish him well.”
While Osbourne is around 6.5ft long, Galapagos sharks can reach 12ft, and are believed to live around 24 years, only reaching maturity at six to nine years old.
The species can be found in the Atlantic, Pacific and Indian oceans, but is considered near threatened by the International Union for Conservation of Nature as the species is caught by commercial fisheries.
Photos Mark Tatem