Dolphins are among the most photogenic creatures in the ocean, and yet relatively little is known about the marine mammals.

Two retired teachers have set out to change that, taking a program for high school students and developing it into a full time passion.

Tony and Phyll Bartram have been collecting data on the dolphin population around Kangaroo Island (KI) since 2006, and at Victor Harbor since 2011.

"At the moment we know so little about these dolphins, and dolphins around the world in actual fact, that they're listed as data deficient on IUCN (International Union for Conservation of Nature) lists," said Mr Bartram.

"So we've got a long way to go to collect enough data to answer a lot of the questions that are raised."

They identify individual dolphins by taking photographs of their distinct dorsal fins.

"Because it's made of cartilage like our ears, if it gets damaged it doesn't heal, so we can then readily identify particular dolphins," Mr Bartram said.

Roger Foster enjoys seeing dolphins thriving on the group's monthly voyages. ( ABC News: Alina Eacott )

Their work is helping to establish an understanding of where the dolphins are at a particular time, and whether there's mingling between the populations.

"Once you know the home range of the animals then you can start to put in place things to protect that habitat," he said.

"All our data collection is going towards protection and conservation."

Mr Bartram said many outside factors can impact dolphins.

"The obvious issue of oil and gas exploration, pollution in the water, plastics, all those sorts of things, and then there are the diseases," he said.

Key to the research is a band of volunteers, who join the monthly voyages around KI and Victor Harbor to take as many photographs as possible.

"What's not to like about it? It's beautiful," said Roger Foster.

"As long as you get to see the dolphins it's just great, I really enjoy the interaction of them, and the people here are a great mob."

Dolphin Watch members Phyll and Tony Bartram with Nedra Haines (C). ( ABC News: Alina Eacott )

On a recent voyage at Victor Harbor, Melissa Brown and her daughter April joined the group for the first time.

"I'm so impressed, it's really admirable that all of these people are volunteering, and Tony and Phyll have dedicated their lives to this," Ms Brown said.

Tony Bartram said the joy the volunteers get out of the work, shows citizen science has benefits that go both ways.

"Some people could say, well it's just cheap labour, but there are enormous benefits to the people that are actually involved in terms of health, wellness, being out in nature, being by the ocean and of course, studying dolphins," he said.

The United Nations recently set an ambitious target of having one billion citizen scientists engaged around the world, after it decided professional science cannot provide enough information necessary to understand environmental change.

The dolphin surveys may well be one example where normal people are increasing that understanding.