The article you've quoted is presenting a hypothesis. The language it uses is tentative - "could have", "plausible cause" etc. The information that the bloom started near the Port Stanvac Desalination plant is also speculation. Nobody knows where it started. We only know when humans started to notice it, which was on beaches facing the Southern Ocean, not in the comparatively sheltered waters of Gulf St Vincent where Pt Stanvac is located. The article is written by a commercial interest, note the Pty Ltd at the end of its name.
A forum of 80 experts in relevant sciences has met in Adelaide and this is what they said:
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