Sadly, toxic algae is continuing to kill fish along South Australia’s coast into May.
Sea life has died in both gulfs, in the south-east and along Kangaroo Island.
The following website is the best I’ve found that shows the diversity of sea life affected (WARNING: it’s grim) … https://www.inaturalist.org/projects/sa-marine-mortality-events-2025
The blooms are blamed on karenia mikimotoi and karenia brevia species of dinoflagellates.
Unfortunately, on social media some people are going for conspiracy theories, such as passing Chinese ships being responsible.
The calm, warm water event leading up to the blooms was well recorded, see our earlier post.
Calm, warm water exists in many places so there must be other contributing factors.
Discussion about the Adelaide desalination plants may be relevant, as there are known links to saline stratification and algal blooms. However the bloom appeared to start far from the plant outlets.
It remains to be seen how long it will take for the bloom to dissipate and for fish to recover.
Karenia blooms are known to be long lasting at times.
Globally, the first bad karenia bloom widely reported, as far as I can tell from online searching, was in 1946 in the Gulf of Mexico.
There is evidence that karenia blooms may be occuring more often in recent times.
