Living Coasts, one of the region's most popular visitor attractions in Torquay is closing down because of the coronavirus pandemic.
Wild Planet Trust says that its other attractions - Newquay and Paignton Zoos - now also risk going out of business because of the unprecedented fall in visitor numbers and cash reserves being wiped out.
More than forty people face losing their jobs at Living Coasts and a further 60 employees have been told that they are at risk of being made redundant at the Paignton and Newquay attractions.
Many zoos have been left facing an uncertain futureafter incurring substantial costs caring for animals during lockdown and simultaneously losing millions of pounds in revenue.
Although English zoos can now re-open, strict social distancing rules are in place meaning that daily visitor numbers will have to be restricted.
Wild Planet Trust says that future uncertainty over how many people will actually wish to visit their largely outdoor attractions leaves them in a critical and precarious position.
Wild Planet Trust boss Simon Tonge said: “In order to ensure the future of Paignton and Newquay Zoos, we are having to make some tough decisions.
"The survival of the zoos will depend on visitors coming to our sites when we re-open over the summer, but more importantly for local people to continue that support throughout the winter, when the zoos historically run at a loss."
New homes will also need to be found for the animals at Living Coasts, and as many as possible will be moved within the worldwide network of zoos and aquariums once movement restrictions have been lifted.
Most of the animals kept at Living Coasts are marine species that will need specialist facilities.
Fundraising campaigns have been in place since 23 March and have raised over £100,000 to date.
The Trust is now appealing for "much, much more" to survive the next few months.