15 April 2011

The algal bloom warning issued for Lake Powell (Albany, Australia) remains in force while, in northern Australia, the warning for Kyogle’s Toonumbar Dam has been lifted. Although slightly off CyanoAlerts subject, a Dinophysis acuminata bloom with toxins has been reported at Northport, (Suffolk, Long Island, USA).

The P-free products movement continues to gain momentum with the Governor of Washington State signing into law a bill to limit the use of phosphorus-based fertilizers in an effort to protect water sources from contamination.  This follows the Senate approval of a bill to limit the use of phosphorus-based fertilizers in an effort to protect water sources from contamination.


Why we monitor chlorophyll? The value of the AlgaeTorch

13 April 2011

Chlorophyll is a photosynthetic pigment produced by plants and algae.  In bodies of water, measurement of the chlorophyll levels tell us how much algae (biomass) is present, on a relative scale.  Chlorophyll is usually measured in the laboratory, on samples of chlorophyll extracted from (obviously) dead algae.  This method does not provide any indication of the types of algae present.

AlgaeTorch being used to monitor a lake for cyanobacteria

The new AlgaeTorch technology (see below on this blog)  has changed all this.  Used as a first line of defence, this instrument measures the chlorophyll directly in the body of water, from LIVING algae.  Even more important is that the device can distinguish between potentially harmful algae (cyanobacteria) and non-problematical (green algae). So, instead of having to wait for samples to get to the lab and be analysed, resource managers can now determine (with 90-95% accuracy) what is happening in the dam, lake or river – and hence what they need to prepare for should they need to take mitigating measures to protect consumers.

In a modest monitoring operation, the AlgaeTorch, compared against conventional sampling and analysis, will pay for itself in less than a month!

CyanoAlert (and some other issues…)

13 April 2011

Some odd comments from South Africa this week:  Firstly, the head of WWF’s conservation programmes has a go at dams in an article entitled “Water does not come from a dam“.  Obviously it doesn’t, but dams are a vital part of South Africa’s very existence and water is STORED in them so, indirectly, most of it comes from dams on its way to the consumer!  Botha correctly observes the need to protect our rivers and wetlands, but seemingly ignores the need to manage dams which, ipso facto, are important components of rivers in our context, as ecological entities (artificial lakes). This is a point that has been critically missed in South Africa and thus our dams are polluted way beyond what they should be (and this, incidentally, this impacts the rivers downstream of dams that Botha is so concerned about).  I see what he is talking about but its a bit of a rant at dams… which I thought we had moved beyond in the post-Asmal era.  South Africa has spent a small fortune on approaches to protect rivers but has, wilfully, ignored the role of the artificial lakes that dam them.

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AlgaeTorch tested at Wemmershoek

11 April 2011

Wemmershoek Dam

Today saw testing of the bbe AlgaeTorch at Wemmershoek Dam (Franschhoek).  The water in Wemmershoek Dam and its perennnial streams is of extremely high quality as there are no human influences in the catchment at all.  Thus this dam provides an excellent site for testing the ability of the AlgaeTorch to function at the low end of the chlorophyll spectrum.

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bbe moldaenke equipment now represented in South Africa!

10 April 2011

the bbe AlgaeTorch is a handheld field instrument

DH Environmental Consulting (DHEC) now provides a local source for the tried and tested range of algal measurement instruments made by bbe moldaenke ( of Kronshagen, Germany.  DHEC, a company specializing in algal issues in water supplies, is currently testing and demonstrating bbe’s AlgaeTorch, a handheld instrument capable of instantaneous algal measurements that can be disaggregated by algal group (ie the instrument can distinguish the cyanobacterial content of the total amount of chlorophyll measured).

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10 April 2011

A relatively quiet week – we are in that period where southern Hemisophere blooms are slowing down, or should be, and those in the north are starting to worry people. Honeoye Lake (Rochester, USA) has been a problem in the past and the locals are hoping that 2011 will be better year for them.  In New Jersey, restrictions on lawn fertilizers have been promulgated, quote “The first steps of the nation’s strictest fertilizer law, which was signed by Gov. Chris Christie in January, went into effect March 13, with the remainder of the law to gradually come into effect throughout the next year”.  Residents of Alice (Texas) have been advised that the cyanobacterial tastes and odours in their water are not harmful.  And, of course, the resistance to the management of eutrophication at source, in this case agricultural sources, continues – as it is destined to do until the water becomes undrinkable! (see also here for a report from Wisconsin and here for Sudbury).  Grand Lake St Marys (Ohio) is about to waste money on another alum dosing exercise, and the locals are getting good information on why the edges (riparian zones) of lakes are so important!

From Australia comes a report that their Aldi Supermarkets group will be banning detergents containing phosphorus!

In South Africa the value of using high surface area floating wetlands to treat stormwater and wastewater has been lauded in an IRIN article.  South has and is being very slow to grasp the potential of this technology, something that could be applied immediately, with no technical management input required, to reduce our water pollution problems!  Also from SA is a report on Lanseria’s new sewage treatment works – the article provides no data on how efficient it is in terms of nutrient levels in the final effluent.  Further east, Loskop Dam continues to be a headache!

History of the Cape Flats Vleis (Part I): Zeekoevlei

8 April 2011

View north over Zeekoevlei (1992)

Zeekoevlei is the largest of the waterbodies on the Cape Flats, at 256 ha.  It is very shallow, with an average depth of just on 2 m.  Despite its long history (almost 100 years now) of having wastewater dumped in it, it was surprisingly healthy until the 1950s when, as a pander to the yachting fraternity, the City Council dosed the lake with sodium arsenite to kill the pondweed.  This dim-witted move, originally proposed and actioned by Edith Stephens for Paardevlei, highlighted the lack of understanding of the benefits of rooted plants in shallow vleis – an ignorance that persists to this day.  Shallow lakes like Zeekoevlei exist in one of two states, either plant or algal dominated.  The dosing of Zeekoevlei simply changed it from a crystal clear body of water, to what it is today.  The report of the City Engineer of the time proudly reports (together with a photograph of their skills in action) that “despite objections from riparian owners, bird lovers and others, a considerable portion of the vlei was treated without adverse effects (sic) on fish, bird life or the littoral vegetation!  Since then Zeekoevlei has been dominated by algae!

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The Cape Flats Vleis: A History

4 April 2011

South towards Muizenberg. Cape Flats early 1900s

After many many years of studying various aspects of the vleis and wetlands of the Cape Flats, I have decided to blog some aspects of their history.  Amongst other things, this will highlight the fact that some of the problems now were also problems “then”.

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2 April 2011

Floating islands at Du Noon, Cape Town

The week ended with wide coverage of the value of using high surface area floating islands to augment various types of waterbodies, in this case for treating stormwater. This blog has posted several articles on this and won’t repeat them here.  The use of floating islands should be seen as part of a ‘toolbox’ of technologies for improving the ecological and water quality characteristics of many types of waterbodies.  They can be used, with considerable effect, in both polluted and unpolluted systems, depending on the desired need (water quality, habitat provision, aesthetics, sediment control, sequestration of pharmaceuticals and so on).

Floating islands being planted prior to launching

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1 April 2011

Bulshoek Dam (Olifants River)

The National Water Act recognizes “the need for the integrated management of all aspects of water resources“.  This implies, or at least I believe it does, that a river should be understood and managed as an integrated whole – i.e. together with any dams or wetlands that form part of its course between source and sea.  South Africa has many dams and only one major river, the Doring, that does not yet have a dam on it.  The Water Act, by the way, does not mention dams other than in the context of dam safety.

This blog has drawn attention to the inattention paid to dams and the apparent lack of recognition of their role as a determinant of our socio-economic future.  The response to a recent parliamentary question has confirmed that dams will continue to be ignored for some time to come and gives the lie to the whole idea of “integrated management”.

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