DH Environmental Consulting

Herewith a few CyanoAlerts to start off March!

A newcomer to Droplets CyanoAlert is Ella Lake – which is in Northern Ontario, rural Canada, one of dozens of lakes just south of the Trans Canada Highway.  Ella has a reported blue-green algal bloom – despite having very low levels of phosphorus (see graphic below) – illustrating the important fact that a little nutrient enrichment can cause a big problem.  Such low levels of Phosphorus is the stuff of dreams for us here in South Africa! Read more »

The US state of Iowa featured a lot in these posts during 2012.  Many Iowan lakes are enriched with nutrients, a lot of which comes from agriculture – not just suspected of coming from agriculture, actually shown to be.  So, how to deal with a big portion of the problem is clear – throw effort at the polluted agric runoff and get it down to acceptable levels.  OK, it may not be that simple as a press report today suggests:

First, unlike the approach used for cities, the strategy continues to rely on all-voluntary farm conservation programs, which have fallen short of protecting our waters in the past. Even though research clearly shows significantly increasing farmer participation in conservation programs is critical for success of the plan, the document does not set timetables or goals to ensure that this will happen. Read more »

And you thought that Spielberg character made up aliens that look like me? (Empusa guttula, female. Photo: Bill Harding)

Things are hotting up down here in the Southern Hemisphere and through the heat haze from my veranda I am kept awake by the regular fall of over-ripe plums from a tree that has become a veritable wildlife sanctuary for all sorts of birds, bees, beetles and the handsome guy in the picture above, well he was just passing through!

The increasing seasonal heat is closely associated with the increased number of algal bloom reports. Read more »

In a first for South Africa, Dr Bill Harding from DH Environmental Consulting (DHEC) will conduct a research survey to test for links between cyanobacteria (blue-green algae) and neurodegenerative diseases (Motor Neuron Disease, MND; Parkinsons Dementia Complex, PDC;  and Alzheimers). Read more »

Typical blue-green algal scum in a farm dam (Photo: Bill Harding)

The commonest form of blue-green algal blooms in lakes and ponds are of the floating, scum-forming variety.  These are easy to spot as the water is very green, often paint-like, scums form at the edges, either in the water or on the rocks. Read more »

Harmful Algal Blooms (HABs) are on the increase globally.  HABs occur when large masses of potentially toxic algae develop in freshwater or marine environments. Typically these blooms are fuelled by increasing human pollution of our water resources, most commonly inadequately-treated wastewater, leading to high concentrations of plant nutrients in our dams and rivers.  A large percentage of South Africa’s water resources are already impaired by the sustained presence of blue-green algae.

Blue-green algae produce a large variety of toxins, singularly or in combination.  Recently it has become apparent that all types of blue-green algae produce an unusual neurotoxin, called beta-methyl-amino-alanine, BMAA.  BMAA in nature is only produced by blue-green algae (cyanobacteria). BMAA is neurotoxic and destroys nerve neurons (e.g. Vyas and Weiss 2009).

Research during the past 40 years has sought to link BMAA with motor neuron disease (Amyotrophic Lateral Sclerosis, ALS, Lou Gehrig’s Disease) and Parkinsons Disease (the so-called ALS-PDC, ALS/Parkinson’s Disease Dementia Complex).  This research has focussed on three locations in the western Pacific where considerably higher than normal incidences of these diseases occur (e.g. Bradley and Cox 2009).  BMAA has been measured in the brains of ALS-PDC cases, but not in control brain tissue, in the aforementioned clusters, as well as in Canada and elsewhere (e.g. Banack et al. 2009).  The effect of BMAA in Parkinson’s symptoms has been confirmed by dosing rats with the toxin (Bradley and Mash 2009).

Read more »

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.

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.

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

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