South Australia is facing a concerning environmental issue, with a harmful algal bloom spreading across the Yorke Peninsula. This bloom has turned the waters a murky brownish-green, posing a threat to local marine life, including southern sand octopus and rays. Worries are growing that it might extend further north into Spencer Gulf, where an annual gathering of giant cuttlefish is expected soon.
The giant cuttlefish migration, which occurs off the coast of Whyalla, is a remarkable natural event. It is the only known mass gathering of these creatures in the world and attracts many from around the globe, including photographers and researchers. Cuttlefish are known for their ability to change color, earning them the nickname “chameleons of the sea.”
Recently, Stefan Andrews from the Great Southern Reef Foundation conducted a survey off Port Victoria and found nearly zero visibility due to the algal bloom. Many marine animals like octopus and starfish were found dead. He described witnessing a vibrant ecosystem become lifeless within just a week. “One week ago, the area was alive with stingrays and various fish. Today, the seafloor is littered with dead animals,” he noted.
This algal bloom is fueled by tiny organisms called dinoflagellates, specifically from the genus Karenia. These microorganisms not only discolor the water but can also irritate human skin. Over the past weeks, parts of the Yorke Peninsula and Spencer Gulf have experienced increased levels of Karenia. However, state officials could not provide recent data concerning the current bloom situation.
Experts like Professor Mike Steer from the South Australian Research and Development Institute have emphasized that the south-west Yorke Peninsula remains the primary area affected by the bloom. He mentioned the state government has responded by increasing monitoring efforts, establishing nine new water testing sites in the area. The testing aims to understand algal bloom trends better, even as the situation remains unpredictable.
The cuttlefish population, generally living between 12 to 18 months, relies heavily on the survival of their eggs. Andrews expressed concern that if the blooms continue to overwhelm their habitat, this year’s reproduction could be jeopardized.
To combat this ecological crisis, the South Australian and federal governments previously invested in a “bubble curtain” at Port Lowly. This innovative barrier aims to protect cuttlefish and their eggs from toxic algal blooms as they migrate.
As scientists continue to grapple with this pressing issue, they face an uncertain future. In November, researchers from Australia, New Zealand, and the UK found that multiple Karenia species were contributing to the harmful blooms. The situation highlights the ongoing challenges posed by climate change and environmental shifts.
For more details on algal blooms and their impact, you can visit the South Australian government’s environmental resources here.
