31 August 2011
Very little in the press today:
The blue-green algae bloom at Lake Texoma is dominated by a type of the toxin-producing algae called Cylindrospermopsis. This is a real nasty and the type of blue-green algae bloom does not look like other BGA blooms that form mats, scum, foam, or have the characteristic “spilled paint” look. Cylindrospermopsis, like the dinoflagellate Ceratium hirundinella, is an alga that is becoming increasingly prevalent worldwide, perhaps in response to changes in salinity and climate. Caution is always the best protection with this beast as there are very few laboratories set up to analyze for the toxin cylindrospermopsin. Read more »
30 August 2011
Early morning today, north-east of Cape Town (Photo: Bill Harding)
Firstly, huge thanks to all who contributed to the flood of very positive comments following last night’s TV programme on phosphates in detergents. I heard from people who I have not contacted for ages! Read more »
29 August 2011
Costings applied to various forms of phosphorus removal Best Management Practices, BMPs, have revealed that the Floating Island technology is the cheapest form of phosphorus removal currently available (see Table). By implication, the islands will do as well for other nutrients, trace metals, bisphenols and other nasties.
Comparative costings of phosphorus removal from water (Source: FI International)
The costing analysis was applied to both conventional wastewater treatment and urban runoff, using Urban Runoff Basins, irrigated rain gardens and the like. These estimates include capital costs and are amortized over 30 years.
28 August 2011
Blue-green algae has been detected at Lake Tabor (Cape Fear) at levels high enough to prompt a public health warning. Swimming has been prohibited at the public access point on Lynwood Norris Street for the past week. Town officials distributed a written warning to stay out of the water to lakefront property owners. Read more »
26 August 2011
In a post towards the end of June this year, I questioned the secrecy behind the decision by Unilever to remove phosphorus from their detergent products without telling anybody. My comment at that time was “The fact that Unilever chose to make this huge change, so apparently covertly, is curious in the extreme, despite the huge benefits that are likely to accrue. It would have been so useful if they could have announced this so that measures could be put in place to track the impact of the change, but they inexplicably chose not to“. Read more »
25 August 2011
Recently there have been some curious and difficult to explain issues around South African government and industrial attitudes towards phosphorus. An American scientist may have insight that we don’t (yet). Read more »
25 August 2011
South Africa’s 50/50 TV programme will host an investigation of the role of phosphates in detergents and how these contribute to eutrophication, or perhaps don’t anymore? . 50/50 airs on Monday, 29 August at 19:30 on SABC2. Read more »
25 August 2011
Its not only in South Africa that scientists get gagged and fired for saying things that industry and others don’t want to hear. Canadian scientist Kristi Miller and her colleagues turned up evidence that many sockeye enter the Fraser in a compromised state, possibly because of viral infections. That discovery was published in January in Science, one of the world’s top research journals. Read more »
24 August 2011
My previous post on Prymnesium parvum, the haptophytic, phagotrophic chrysophyte, reminded me of the Vermont Pan, a small, endorheic (internally-draining) salt pan near Hermanus on the South African southern coastline, quite near the southernmost tip of Africa. This pan does not support fish and is one of the localities where I have found both Prymnesium and its close relative, Chrysochromulina. Read more »
24 August 2011
The tiny Chrysophyte, Prymnesium pavum, is plaguing lakes suffering from drought in the US south-west. Prymnesium is a highly-specialized alga belonging to a group known as the golden algae. Prymnesium proliferates under very specific, sometimes highly-variable, conditions of physico-chemical stress in lakes – typically slightly-elevated salinity and nutrient stress that precludes ‘desirable’ algae from competing. It also produces compounds that are toxic to fish, resulting in massive fish kills.
Haptophytes are important in the aquaculture industry – but not Prymnesium or Chrysochromulina – which form icthyotoxic blooms.
I am aware of two fish kills caused by Prymnesium in South Africa, both in Cape Town. The first was back in the 1970s in Zandvlei, the second a couple of years ago in Rietvlei (although it was completely missed by those investigating the case). Because it is so small and hard to see, it is often missed by inexperienced microscopists.
I am pleased to part of a group seeking an immediate relief solution for this problem!