A study that will look at whether the last five captive dolphins in New South Wales can be transferred to a sea pen sanctuary has been officially launched, in what could be a globally significant development.

Organisations World Animal Protection and Action for Dolphins have joined forces to test the feasibility of a sea sanctuary for the mammals who call Coffs Harbour's Dolphin Marine Magic tourist park home.

Action for Dolphins advocacy director Jordan Sosnowski said while they would like to see the dolphins return to the ocean, their lifelong captivity was a grave concern.

"The issue is that these dolphins lack the necessary survival skills to be released into the wild, so creating a sea pen sanctuary for them will be creating a humane home in the ocean," she said.

"It will be netted off, it will be a very large area, and the dolphins can forage on the ocean floor, they can feel the ebb and flow of the ocean tide, and hopefully really learn to hunt for fish again."

City harbour considered as location for pens

The study forms part of a negotiated settlement resulting from Action for Dolphins suing Dolphin Marine Magic earlier this year.

Issues of animal welfare, engineering and the financial implications of moving the mammals will be investigated during the study.

One of the two locations being considered for a sanctuary is within the city's harbour.

Ms Sosnowski said that location could mean the dolphins could still be visible to the public.

"We may need that [tourism] aspect as part of it to be able to keep up the running costs and have enough fish to feed the dolphins," she said.

"I think it is possible to create a sanctuary where people could view the dolphins from afar, maybe from walkways, but we definitely don't want people riding on the dolphins or kissing the dolphins or getting in the water with them at all."

Coffs Harbour sea pen could be a world-first

The findings of the feasibility study are likely to be announced by early 2019, and World Animal Protection senior campaign manager Ben Pearson said it could have global implications.

Protestors targeted Dolphin Marine Magic last summer for keeping dolphins in captivity. ( ABC Coffs Coast: Dom Vukovic )

"Around the world there are dozens of dolphinariums and aquariums which hold dolphins," he said.

"Some of them are starting to look at whether they can move their dolphins to a sanctuary, but there are not many of these things happening.

"So what we're doing in Coffs Harbour — the study we're announcing — is one that will be globally significant."

Mr Pearson has also called for Sea World on the Gold Coast to start investigating the feasibility of a sea sanctuary there.

"We certainly hope that following this announcement they might come forward and tell us what their plans for the future are," he said.

Tourist park open to findings

Moving dolphins to a sea pen would have major implications for Dolphin Marine Magic, which conducts dolphin shows daily.

But the local tourism icon is supporting the study.

"At the end of the day, it's the dolphins' welfare that we have first and foremost, and if the sea pens are a viable proposition, then obviously that will be a good environment for them to go into," managing director Terry Goodall said.

"But a lot of study has to be done both on the dolphins and the very viability of the sea pens in this location."

Signs outside Dolphin Marine Magic outline the rescue and rehabilitation work done on site. ( ABC Coffs Coast: Melissa Martin )

Mr Goodall said sea pens would not signal the end of the tourist park, which was repositioning its business model.

"If it looks like being the best option for the dolphins, then we will simply have a bit further to run to look after them, because they'll still need looking after," he said.

"We will have to be always looking at the pH of the water, and whether they're getting the right food, if pollution's a problem.

"So we'll still be required to look after those dolphins and we'll just have to see how we can reposition that as part of an educative program for the public."