The recent activation of the Adelaide desalination plant and the coincidental toxic algal bloom causing widespread deaths of marine fauna are causes for concern (“The blobs: our
ocean horror”, The Advertiser, 20/5).
The epicentre of the bloom was next to the Adelaide plant, which discharges brine and maintenance chemicals into a relatively sheltered near-shore environment.
Notably, to reduce harmful impacts, dispersion jets are used to dilute brine and potentially toxic chemicals at the point of discharge.
In doing so, the strong jets can mobilise sediments which harbour cysts of toxic algal species, including the algae behind the current devastating bloom.
This disturbance to near-shore sediments, and conditions favourable for a rapid increase in the growth of toxic algae such as elevated temperature, nutrients and sunlight, present plausible causes of the bloom.
Statements which exclude desalination discharge as a cause are inconsistent with desalination plants elsewhere in the world, which have been associated with harmful algal blooms.
Instead, a precautionary approach should apply to the siting and operation of desalination plants, particularly in relatively sheltered coastal areas close to valuable biological resources.
Professor Paul McShane (marine biologist),
Dr Ib Svane (zoology, marine biology)
Glen Ingham (PIRSA Seafood Industry Development Manager (retired)
No comments:
Post a Comment