Red tide - you can run but you can't hide. Super-sleuth Dr Tommy Bornman from SAEON has managed to nail an ID onto the predominant critters in the algae blooms off our coast.
Introducing Protoceratium reticulatum, or let's just call him Mr P. Turns out Mr P is two things, first is that he's lost, second is that he's toxic. Sort of. He's previously been recorded in the North Sea, off the coast of Brazil and the Southwest Atlantic (west coast of the Western Cape). So what he's doing in PE who knows. No doubt climate change will be partly to blame cos of changing currents, winds and water temps. Prof Peter Britz from the Ichthyology department at Rhodes points out that harmful algal blooms are increasing around the world as ships move toxic species in their ballast water. Any increase in nutrient pollution thanks to things like sewage effluent provides the fertiliser they need to breed like bunnies wherever they land up. Mr P's species is listed by UNESCO as a harmful microalgae. It's been proven toxic to mice. But that's only really when you inject them full of the stuff. If they swallow it, not so bad. It's effect on humans is still unknown. A bunch of studies have sussed out the potential toxicity of the yessotoxins that Mr P produces. To date none of them have found any toxic effects when they are present in humans. Just the poor mice don't seem to do so well when spiked with it. So although no data exists to point a finger at a direct association of the yessotoxins causing problems for humans, the warnings of their potential health risks to us still stand due to the significant animal toxicity observed. It's a tough lil bastard, cos unlike other algal toxins present within shellfish, this stuff isn't destroyed by heating or freezing. Wonder if the perlie poachers will be printing a health warning on the bags of perlemoen they're smuggling out? So there ya have it - don't feed your pet mouse mussels or oysters. And it would be a good idea not to eat them yourself either. Just to be safe rather than sorry. Probably fine to surf in it, provided you don't gulp down gallons of it. Brad & Scott - your Noordhoek sesh in the stuff won't kill you! PS - take a drive out to the Schoenies/Maitlands area at night to go check out the amazing light show. It does depend on the wind & weather as to how big the plankton party is, so you don't know til you go. But if you luck into seeing a rad display it'll be so worth the effort. Even the sand glows under you feet. Thanks to Dr Tommy Bornman (SAEON), Dr Shirley Parker Nance (NMMU) and Prof Peter Britz (Rhodes) for the info. UPDATE: Turns out this ID was not correct. Samples sent off to experts in Croatia have returned findings of another, far more poisonous species. See here for more details. Here's some shots from Friday night at Maitlands. And yip - it really does look that blue in real life! Went and saw it for myself.
Peter Britz
1/24/2014 05:58:11 pm
Dense algal blooms can cause harm in two ways 1) the toxins they produce and 2) they can suck all the available dissolved oxygen out of the water at night due to their cellular respiration or when they die off and the decaying critters elevate the "biological oxygen demand" associated with the oxidation and decay of the dead cells. When algae cause low oxygen, we call it a "black tide" and this causes the phenomenon of crayfish walking out of the water on the West coast at Elands Bay and other spots.
millerslocal
1/25/2014 03:39:37 am
Bad news. Turns out the second effect that Peter explains above has started. Just heard reports of fish dying at Sards. Scientists on the scene collecting samples and data. Comments are closed.
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AuthorMillerslocal Archives
July 2021
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