Picton's aquarium has been ordered to close but its staff aren't going quietly, staging a sit-in to stop the building being taken over.
EcoWorld director John Reuhman says Port Marlborough will take over the building's lease from midnight on Thursday.
EcoWorld staff and members of the public plan to occupy EcoWorld’s building in a last-ditch attempt to save the aquarium, the animals and the jobs of its six employees.
"We are going to do an occupation to try to save it all. It's a crazy situation," says Rheuman.
He says while the land animals will be rehomed, the marine animals will be "slaughtered".
"They can't fend for themselves if they were released, they can't feed themselves, they can't defend themselves," he told Newshub in June.
"The only humane thing is that they'd have to been euthanised."
More than 4000 people have signed a petition pleading to save the aquarium, but Port Marlborough has been resolute in closing the building's lease.
In a statement earlier in June Port Marlborough chief executive Rhys Welbourn said it's offered to support the aquarium.
"Some time ago Port Marlborough and Ecoworld discussed a possible extension of the lease. However, Ecoworld sought different terms that were not acceptable to Port Marlborough and this has been consistently conveyed to Ecoworld.
"Therefore the lease has come to an end in accordance with its agreed terms. We are now trying to help the business vacate its premises, and assist with the sustainable rehoming of the aquarium's marine life and other animals."