[10] Using neurally controlled cells known as chromatophore organs (red to yellow), iridophores (iridescent: spans the entire visible spectrum from blue to near-IR) and leucophores (white), the cuttlefish can put on spectacular displays, changing colour and patterns in a fraction of a second.

[16] Because the optic lobes of cuttlefish are larger than any other region of the brain and their skin produces polarised reflective patterns, they may communicate through this visual system.

[18] A bioenergetics study found that the giant cuttlefish is primarily diurnal and has a small home range (90–550 m or 300–1,800 ft) over short recording periods while travelling large distances to breed.

[22] This has raised concerns about Yellowtail kingfish escapees from commercial fish farms impacting other species in Spencer Gulf[23] including eating emergent Giant Australian cuttlefish or their eggs.

Discovered by divers in the late 1990s, the upper Spencer Gulf population is the best studied, largely because it is the world's only known mass cuttlefish-spawning aggregation.

[10] Professor Roger Hanlon of the Woods Hole Oceanographic Institution has called the breeding aggregation "the premier marine attraction on the planet.

[10] An unsuccessful application to list this population of giant cuttlefish as a threatened species under Australian law was made during the government's consideration of BHP Billiton's Olympic Dam mine expansion project.

The application was made following an observed and unexplained population decline and public concerns about future risks posed by industrial pollution.

Prior to the mid-1990s, the upper Spencer Gulf population was fished for snapper bait, with annual catches of around 4 tonnes (4,000 cuttlefish).

[27] The closure was subsequently expanded to the entire spawning grounds, and anecdotal observations suggested increased numbers in 2006 and 2007; however, a new survey in 2008 found the biomass had decreased a further 17%.

Local fishermen claimed that a small "finger of land" near Point Lowly extends outside the exclusion zone and that commercial fishers have been targeting the area, intercepting the squid before they can reach the spawning grounds.

Being semelparous breeders, ecologist Bronwyn Gillanders believed the cuttlefish were in danger, stating that determining whether this is a natural phenomenon or something else is difficult, and that the cause requires more research.

[citation needed] Tour guide Tony Bramley, who had been taking divers to view the spawning grounds since they were discovered, stated, "It's heartbreaking, when you look at what's left ... [once] there were so many animals you couldn't land on the bottom, you had to push them aside.

"[30] The Conservation Council of South Australia, which believes the population to be a separate species based on unpublished scientific data, warned that the Spencer Gulf cuttlefish faced possible extinction within two or three years if nothing was done to better protect them.

"[15] On 28 March 2013, the state government introduced a temporary ban on fishing for cuttlefish in the northern Spencer Gulf for the 2013 breeding season.

Fisheries Minister Gago announced that research into the reasons behind the 90% decline in the cuttlefish population had ruled out commercial fishing as a cause, but was otherwise inconclusive, and that further areas of Spencer Gulf would be closed in 2014.

Some concern exists over the possible impact of the plant on the cuttlefish population and two major contamination events have happened at the associated port and refinery.

Since that time, two new, smaller scale seawater desalination plants have been commissioned and discharge brine into the gulf: one at the Whyalla Steelworks and another at Sundrop Farms, south of Port Augusta.

Increasing shipping traffic in the upper Spencer Gulf has the potential to impact cuttlefish behavior due to cephalopod sensitivity to high intensity, low frequency sound.

[45] The upper Spencer Gulf cuttlefish aggregation is celebrated each year by Cuttlefest, an event hosted by the City of Whyalla.

Some controversy surrounded the performances after a participant in the project was openly critical of the plan to build a desalination plant at Point Lowly.

During the Adelaide Fringe Festival in March 2012, the RiAus presented Sepia, an original work by Welsh playwright, Emily Steel.

[49] Set in Whyalla, the play told the story of the fictitious character Neil, the proprietor of a caravan park who was struggling to come to terms with the cuttlefish decline whilst trying to keep his family together.

Santos was responsible for hydrocarbon groundwater contamination at Port Bonython, adjacent to the cuttlefish breeding grounds, first discovered in 2008.

Stobie the Disco Cuttlefish first appeared during the Adelaide Fringe Opening Parade, then performed with a troupe of dancers each Saturday night during the festival.

[51] The soundtrack to the performance included samples from the Bee Gees hit "Stayin' Alive"[52] and the entire theme song from the movie Fame.

[33] The mass aggregation of giant cuttlefish at Point Lowly has inspired the development of a retro computer game called Cuttle Scuttle.