The Eutrophication Discontinuity

11 January 2011

Over time there have been two big changes in the movement of nutrients from human waste or activities into the aquatic environment.  The first was in the late 1800s when the discovery of guano replaced the use of nightsoil as a fertilizer.  The second, demonstrated by water quality measurements, occurred in the 1950s as post-war development and movement to cities saw a marked increase in sewage generation and disposal – evident as a sudden and massive increase in surface water P-levels.

P-discontinuity for Hartbeespoort Dam

A group of researchers from Canada have produced elegant and similar results using diatoms!  Diatoms can be used to historically infer a lot of things, including what the prevailing concentrations of phosphorus were (=diatom-inferred total phosphorus, DI-TP).  An important conclusion from their work is that  lakes situated in catchments that have had a long history of agriculture or elevated population densities may not be able to fully recover from excessive nutrient loading. Research to understand when lakes cross this ‘point of no return’ will be an important next step to managing eutrophication and restoring eutrophic lakes.

How seaworthy is the South African ship?

10 January 2011

The Challenge for Africa, the book written by Kenyan Nobel Peace Prize winner, Wangari Maathai, should be prescribed reading for all South Africans.  In a few short paragraphs she itemizes the generic problems facing Africa and the role that African leadership has played in its own undoing.  By way of example I would like to quote some passages from this work and let you decide if you see any homegrown similarities:

  • One of the major tragedies of postcolonial Africa is that the African peoples have trusted their leaders, but only a few of those leaders have honored that trust. What has held Africa back, and continues to do so, has its origins in a lack of principled, ethical leadership.
  • If African states had prioritized the budgets and work of the ministries of agriculture and environment, instead of defense and internal security – indeed if governments had concentrated on practical measures that helped their people rather than, at times, investing in grandiose, attention-seeking projects or misguided attempts to satisfy the demands of outside investors, often at the expense of their own peoples…
  • If the continent’s governments had organized their development priorities so that productive land was used more wisely, natural resources conserved and suitable urban planning undertaken…
  • If African leaders had invested more in education, the creation of sustainable employment options, and inclusive economies, and if they had been concerned with the welfare of their people and not their own enrichment…

Sound at all familiar?

Can the Water Crisis be bailed out?

7 January 2011

Can the water crisis be bailed out?

The findings of the Commission into last year’s Deepwater Horizon blowout concluded that, ultimately, the disaster was due to a single failure: Management.  When decisions were made, no one was considering the risk.

The same risk assessment applies to our water crisis – managers do not see the bigger picture and see the dangers of sustained inaction (as opposed to the much touted and perhaps an oxymoron, sustainable development).  This has been going on for a long time

One has to ask, what are the regulator’s advisors saying?  Are the advisors perhaps the same people who advised us into this mess in the first place?  If so then they are not likely to be keen to expose their own ineptitude.   There seems to be a marked resistance to engaging with newer, relevant skills and thinking.  Coupled to this is the problem that the path between decision makers and scientific opinion has become so long and convoluted – as a consequence of skills loss, inappropriate affirmative action and other issues, that it is essentially not viable.  Managers and decision makers have no ready avenue or support structure on which to base their conclusions.

Now, more than ever, is the need for a non-aligned colloquium of residual skills and knowledge. The DWA has been reluctant to take up this challenge and industry will need to underpin such an approach.  If not, then the costs of production are going to become punitive for many manufacturers.


7 January 2011

Six messages from Australia today – the alert level on the Murray River has been lifted, while in New South Wales a Red Alert has been issued for the Carcoar Dam.  On a loosely-algal related matter, there is a report of a programme to eradicate tilapia from waterbodies in the Bundaberg area – I wonder how that is working for them as when I last looked Bundaberg seemed pretty deep under water – the redistribution of tilapia is probably going to be quite widespread through Queensland when the floodwaters recede! The same flooding has been deemed a plus for Lake Julius Dam (Queensland), diluting out the blue-greens.  Further away, Pykes Creek Dam has an algal bloom.  Lastly, Lake Eppalock (Goulburn Murray) has reported an algal scum.

In America the war on phosphorus continues, with new toughened regulations being imposed in Florida and New Jersey.  In Florida the EPA has assessed that 1,918 miles of rivers and streams, 378,435 acres of lakes and 569 square miles of estuaries in the state are impaired by nutrients!

From Texas, a recent large fishkill has been attributed to toxin and odour forming algae in Lake Meredith.

From China there is a report that scientists have developed a sensor for measuring microcystin-LR, the most common variant of the microcystins.  If this works it will be a major step forward for realtime monitoring of raw potable water.


6 January 2011

Some algal bloom conditions persist quite far into the northern winter: the alert for Lost Creek Lake in Oregon has only now been lifted!  In Australia, the Canning River is again off-colour with a bloom of the relatively-rare Karlodinium micrum.  Karlodinium is not a cyanobacterium, rather a toxin-producing dinoflagellate – commonly associated with fish kills.

In the US, Wisconsin authorities continue to strengthen their fight against phosphorus, with restrictions for Lake St Croix being published.  In the US use is made of TMDLs (Total Maximum Daily Loads) – a means of determining the acceptable phosphorus loading and then apportioning this amongst the polluters.  In South Africa we have yet to apply Total Maximum Annual Phosphorus Loads (TMAPLs) – even though most of our key dams exceed the problem limits by up to 95%!

On the warm side of the USA (California), a TMDL has been set for the Klamath River, long plagued by cyanobacterial blooms.  The TMDL requires that phosphorus be reduced by 57 percent, nitrogen by 32 percent, and carbonaceous biochemical oxygen demand by 16 percent.   South Africa requires a new advisory mindset if we are to get even close to implementing this aggressive type of management.  Thusfar we seem to have the same people who advised us into the mess we are in still at the helm!

A value-adding use for the Athlone Power Station

4 January 2011

Athlone’s towers have fallen down

I understand that the huge building that was the Athlone Power Station is being considered for a museum of some sort?  The odds are probably quite good that it will be developed into a shopping mall.

The site is immediately opposite the long-overloaded Athlone wastewater treatment works – a works that has no space to expand to meet increasing demands.  When the cooling towers came down, I suggested (to the City) that it would be a good idea to fill the building with reverse osmosis water purification modules and treat the otherwise ghastly final effluent to a useable, and saleable, quality (RO can achieve potable quality).  This, to my mind, would be a logical and strategic use of space.  There is already a pipeline from the works as the effluent was used as cooling water for the towers.

The concept of converting waste, in this case wastewater effluent, into an asset (irrigation, drinking or industrial water) is not taking root in South Africa – but it needs to!  This approach would also allow recovery of the appropriately-named Black River from its present role as a wastewater drain.

Data on global phosphorus usage released

4 January 2011

Too much phosphorus is not a good thing......

A market research report has been released that details the global trends in phosphorus demand to 2015.  This confirms the declining usage in developed countries, as a consequence of fertilizer controls and removal of phosphorus from detergents (see elsewhere on this blog), and increasing use in developing countries (not good use for our waterbodies unless our government gets its act together).  Given that China and Brazil are the biggest producers – and our somewhat mysterious inclusion in BRIC, I forsee that we will continue buying lots of phosphorus during the next few years.

Key to the Algal Flora of the South-Western Cape, South Africa

3 January 2011

Micrasterias radians (Desmidaceae)

There will shortly be a new addition to the DHEC website.  Over the past 20-odd years I have amassed data on the algae occurring in the dams, rivers and vleis of the south-western Cape.  A lot of this material is pre-digital age (slides and prints) and I have scanned-in several hundred images of my work from the early 1990s.

The phytoplankton, in particular, of the waters of the Western Cape are poorly-described and this dataset, together with its physico-chemical data, provides a comprehensive photomicrographic record of the microalgae from this region.  The underlying research work is currently being prepared for a publication on the applicability of Colin Reynolds functional classification of the freshwater phytoplankton.

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