· In short: A whale and two dolphins stranded and died in Port Lincoln three days after a seismic survey was conducted for SA Water.

· Greens MLC Tammy Franks claims the death of the whale could be a potential environmental breach.

· What's next? SA Water says the death is unrelated to the survey and is pushing on with its desalination plant plans at the site.

SA Water has been accused of environmental malpractice after the death of a pygmy whale and two dolphins near a seismic testing site in South Australia's Port Lincoln.

Seismic surveys use air guns to generate sound signals that can penetrate the earth under the sea to help determine site geography.

The sounds generated are of a high frequency, and some studies show the surveys can disrupt the behaviour of animals.

A survey took place off Billy Lights Point on February 22, where SA Water has proposed its desalination plant.

A pygmy right whale was stranded on a beach at Spalding Cove near the testing location three days after the survey and died.

It was discussed on a community message forum prior to this, that a whale and its calf were swimming in Proper Bay near the test site.

Information request

Former senator and submariner, Rex Patrick, said he wanted to find out more information about the whale and its death so he submitted a Freedom of Information (FOI) request.

The FOI revealed two dolphins that were also stranded that day later died.

The former senator is an acoustic expert, and previously built seismic sonars used for similar surveys.

He said the frequency of the surveys conducted in Port Lincoln peaked at 220 decibels which were "really loud" and at the same noise level the navy used to find submarines.

"It works at the same frequencies that whales and dolphins communicate at," he said.

Potential breach

Greens MLC Tammy Franks has reported SA Water to the federal government for a potential breach of the Environmental Protection and Biodiversity Conservation Act, in relation to the whale death.

She said she wanted to ensure appropriate steps were taken by the water authority to protect animals with the survey.

Ms Franks said science showed the tests could impact mammals within eight kilometres, which was how far away from the survey the whale stranded and died.

"The science says eight kilometres and eight kilometres was indeed, where this pygmy right whale calf was at the time," she said.

Whale death unrelated to survey

A SA Water spokesperson said the organisation employed stringent control measures during the survey to prevent damage to marine life.

"These measures follow … guidelines … overseen by the federal Department of Climate Change, Energy, the Environment and Water," the spokesperson said.

The spokesperson said SA Water employed a marine mammal observer who monitored animal activity within three kilometres of a survey, and "there were no marine mammals" spotted.

"[There are] strict protocols in place to immediately lower the power of acoustic devices if a whale enters within 1-kilometre of the survey area or shut down if they enter within 500 metres," they said.

The spokesperson said there were other deaths of whales around Eyre Peninsula in January and February when surveys were not happening.

"There's no evidence to suggest any connection between the reported stranding in late February and our geophysical activity," it said.

However, Mr Patrick said the frequencies were known to cause damage to mammals — and said the deaths could have been a result of the surveys.

"It's well known that marine mammals will beach themselves in circumstances where they've been confronted with very loud signals from seismic surveys," he said.