CyanoAlert

29 December 2010

From Sri Lanka we hear the disturbing news that cyanotoxins have been linked to kidney disease.  3150 deaths have been reported during the past 14 years in the North Central Province. This further compounds the complications already posed not only by the direct toxicity of these compounds, but also those linking cyanobacterial to ALS and Alzheimers (more on this on this blog in the New Year).  Worryingly, a comment made re this announcement was “hope she won’t lose her job” – referring to the scientist responsible! Here in SA we have seen a few people lose theirs for telling the truth!

Although not a freshwater incident (it could be), 11 people in Zihuatanejo, Acapulco have been poisoned by saxitoxins accumulated in clams.

CyanoAlert

27 December 2010

Lake Atitlan in Guatemala had a bad year – algal blooms in a large lake hitherto unaffected by this scourge.  I was invited to attend a special working group in September (2010) but funding was not available – despite a formal request to the WRC (I have been consulting to them since 2004 on  their toxic algal strategy and also representing them on the GWRC Toxic Algal Working Group.  Lets hope 2011 brings them some success.

Despite the seasonal cold, Willow Lake (Oregon, USA) has only just had its algal-initiated closure lifted.  The first warnings for the Rotorua Lakes (New Zealand) – regular algal bloomers – have been issued, and a second warning for Lakes Forsyth and Wairewa in the Canterbury District.

International Manual on Cyanobacteria

27 December 2010

Arising out of a GWRC (Global Water Research Coalition) meeting held in Australia in 2004 was a resolution to produce an international manual dealing with all aspects of Cyanobacteria (blue-green algae).  The groundwork for this manual was formulated at a workshop held in Somerset West during 2007 – organized by DH Environmental on behalf of Mrs Annatjie Moolman, Research Manager for toxic algal issues at the Water Research Commission.  The manual was published recently and is available via in the internet.  Five South Africans contributed to the formulation of this important document.

GWRC Special Working Group Meeting, Somerset West, 2007

Merry Xmas to All

24 December 2010

Sunset in Somerset West, South Africa

Wildevoelvlei

24 December 2010

Wildevoelvlei (Noordhoek/Kommetjie, Cape Town) remains in the news.  I haven’t seen the vlei this time around but given that the City has actually moved to issue such a strong warning, it must be serious.  In keeping with overseas trends, it would be useful if they would also release the associated data (algal biomass levels, toxin concentrations and etc).

As I mentioned before, the vlei is an extension of the adjacent sewage works – i.e. a maturation pond.  This situation will persist until such time as the works adopts a stringent policy of phosphorus removal.  There is an interim, off-the-shelf technology available that would address this problem, in-lake, immediately – this being the forced circulation version of the BioHavens (see elsewhere on this Blog) – namely the aptly named Leviathan!  This would turn the eastern basin of the vlei into a biological viable, non-algal dominated environment within the space of weeks – and permanently into the future.

This type of approach was suggested as a follow-up to the salting exercise back in the late-1990s – and local trials revealed that the approach was likely to work.  My experience of this type of situation is that, typically, more money is spent on trying to find a cheaper solution than the cost of the originally-proposed intervention!  The dredging of Zeekoevlei is another such example.

Wildevoelvlei biofilm generation trials, 2003

CyanoAlert

23 December 2010

New Zealand.  After last month’s Hutt River outbreak, today’s warning comes from the Selwyn River in the Canterbury District.  New Zealand has an excellent Google Maps linked information system and some really good information websites – such as this one from the Greater Wellington Council.  It also provides links to their database of warnings.

The Importance of Diatoms

22 December 2010

The importance of diatoms as additional indicators for industry, mining and municipalities

Cyclotella meneghiniana

Diatoms are microscopic organisms, mostly less than ½ mm in length, which comprise approximately 40% of all algal assemblages. These organisms are important primary producers, providing both oxygen to the environment and a food source for primary and secondary consumers.

The diatoms are unique in that their cell wall is composed almost entirely of silica, thus they are extremely robust. Diatoms grow rapidly and communities can give an integrated overview of the prevailing water quality, for several weeks to months, on a small spatial scale. Diatoms persist in all habitats (rivers, streams, canals, ditches etc.), even in the most polluted, and are thus excellent universal indicators with well documented environmental tolerances.  They have proved extremely valuable for tracing the effects of acid mine drainage.

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CyanoAlert

22 December 2010

Australia: Cooby Dam (Toowoomba) has been closed to the public – which has put a damper on planned Xmas recreation.  Also in Oz, algae have been found in the water supply to Port Macquarie (Port Macquarie and Cowarra Dams).  While they don’t say what type of algae, they do mention musty odours, which points to cyanobacteria being the most-likely problem.  In Canberra, as well as in Windermere and Burrendong Dams, an increased frequency of algal blooms is starting to affect the economic stability as sporting groups seek cleaner waters.

Back home there have not been any updates on the Wildevoelvlei outbreak but the surfing community are concerned as the discharge from the vlei is at Noordhoek Beach. I wonder if they know how long this problem has been around?  However, warnings for the already massively-stressed Vaal River again highlight the long-denied Water Crisis warnings!

Vaal River Crisis

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Floating Islands – Nature’s Marvel

22 December 2010

Floating islands are a natural phenomenon – the benefits of which have now been ‘bio-mimicked’ into a commercial technology – one of the most exciting innovations for decades.  While many have tried to create ‘floating wetlands’, to-date only a single company has been successful in combining all of the abiotic and biotic components necessary to create a semi-natural biological engine.

Planting a new floating island

The first scientific evaluation of floating islands was published way back in 1711.  Since then there have been numerous reports and publications on this natural phenomenon (see Floating Islands, A Global Bibliography by Van Duzer – Cantor Press).  Relatively recently, Floating Islands International (Montana, USA), has created an inert, floating matrix known as a BioHaven.

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Why diatoms are valuable indicators of water quality

16 December 2010

A small centric diatom

Diatoms provide probably the most versatile and important biomonitoring tool for aquatic environments.  Located at the base of the aquatic foodweb, mostly in epiphytic and/or episammic forms, diatoms are “glued” into their environment and are not nearly as prone to washouts or other changes in hydraulic regimes that directly affect planktonic indicators (vertebrates or fish).  They integrate changes in water chemistry, including pollutants, rapidly and at a fine scale, information that is not provided by aquatic or terrestrial vegetation indicators.  Lastly, their occurrence is not habitat-dependent, as is the case with vertebrates or fish.   They are the easiest indicator to sample, from streams, urban canals or wetlands, being generally equally represented across all surfaces at a single location.

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