The site of the world's largest cuttlefish aggregation

Today’s Image of the Day from NASA Earth Observatory features Spencer Gulf, which indents the southeastern coast of South Australia. Every winter, thousands of Australian giant cuttlefish make their way here to participate in the world’s largest known aggregation of cuttlefish.

Australian giant cuttlefish can grow to nearly a meter long. They have special skin cells called chromatophores that allow them to change the color, or even the texture, of their skin to attract mates and evade predators.

Over the decade leading up to 2013, the cuttlefish population had declined by 90 percent, prompting a fishing ban in False Bay – the northern part of Spencer Gulf. By 2020, the population had rebounded from fewer than 20,000 cuttlefish to about 250,000, and the exclusion zone was scaled back. 

According to NASA, the light-colored swirls that are visible in the water in False Bay are caused by sediment brought to the surface when strong winds churn shallow parts of the gulf. 

The image was captured on September 8, 2021 by the Operational Land Imager (OLI) on the Landsat 8 satellite. 

Image Credit: NASA Earth Observatory 

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By Chrissy Sexton, Earth.com Staff Writer