South Australia is being seriously affected by ongoing ocean algal blooms of Karenia mikimotoi, resulting in the widespread marine die off. The toxicity is not fully understood, but it is non-toxic to humans, with some allergic reactions and skin irritation. However, it has killed and stressed marine life. Also, reducing oxygen levels and water quality.
Karenia mikimotoi is a dinoflagellate species. First observed in Japan in 1935, and since then, it has been observed on the east coast of the United States, Norway, the English Channel, and now in South Australia.
Image: micrograph of K. mikimotoi
National Oceanic and Atmospheric Administration (NOAA)
Why is it here?
The Southern Ocean, naturally brings nutrient-rich deep waters to the surface and play a pivotal role in replenishing upper-ocean nutrients. However due to climate change, the oceans have warmed, and the combination of warmer waters and nutrient-rich ocean provides ideal conditions for algae to thrive. South Australian waters, in particular, have been experiencing a marine heatwave of 2.5 °C above average. At the same time an increased in the Marry River outflow due to record high flooding along the River Murray between November 2022 and February 2023 the largest flood event since 1956 adding a sudden increase in nutrients for the algal blooms to accelerate and increase in scale.
How is it monitored?
Most notably, it changes the colour of seawater, and widespread death of marine life or a green-yellow foam discolouration on the seashore with inshore breezes. Due to its colour, satellite measures of chlorophyll-a (Chla) levels, an indicator of algae concentrations, show that elevated Chla concentrations persist across most coastal regions within Upper Gulf Saint Vincent, as far south as Edithburgh in the west and Aldinga in the east.
For local monitoring algal contamination, it is common to use water quality sensors that include pH, dissolved oxygen, turbidity, TDS, suspended solids, UV-COD, and spectrofluorometer sensors.
South Australian Research and Development Institute.
> Harmful algal bloom (HAB) situation update. –
What can be done?
Although reversing the effects of climate should be a global priority, sadly it isn’t coming anytime soon and may get a lot whose.
Supporting and investing into research in ways to build mitigate, resilience and rehabilitate our oceans, speak with local, state and federal government representatives.
Citizen Science, can help in tracking the distribution of algal blooms across SA seas, helping Scientist to understand better the causes and effects of this serious outbreak.
Summary:
- Reversing Climate Change
- Remediation of sea grasses and native oyster beds
- Reducing nuetrigents outflow into rivers from domestic and commercial activity
- Bubble curtains to protech indagered sea wildlife areas
- Large scale engineering projects