Ruth Patrick: A scientist way ahead of the game

29 September 2012

This post continues the history of South Africa’s Father of Diatomology, Béla Cholnoky.  Béla lived from 1899-1972.  A contemporary of his, Ruth Patrick (1907-  ) undertook a very similar path of work and discovery in the USA – with the exception that Dr Patrick’s work was highly-visible and influential of national and federal aquatic monitoring policies as long as half a century ago.  It is my belief – and that of my colleagues, that Dr Cholnoky would have sincerely wished for a similar outcome in South Africa.  Algology, however, has not ever held high value in scientific circles in this country and the value of diatoms was wilfully ignored by some who should have known better.

This post, with the kind permission of the Academy of Natural Sciences at Drexel University (Philadelphia), provides a biography of Dr Patrick.  The Academy includes the Patrick Center for Environmental Research, a component of which is a diatom-focussed phycology unit, currently led by Dr Don Charles.  Dr Patrick turns 105 in November!

Obituary:  The inspirational and pioneering freshwater ecologist Ruth Patrick passed away recently at the age of 105!  Herewith a link to the BBC Last Word programme in which there is a informative clip on her life and abilities (about 12.5 minutes in).

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Béla Jenö Cholnoky: An Obituary

28 September 2012

Béla Cholnoky

This post continues the history of the achievements of the Hungarian diatomologist, Béla Cholnoky, known as The Father of South African Diatomology.  In this edition I have used the text of the obituary prepared by Dr Archie (R.E.M) Archibald, a diatomologist trained by Béla: Read more »

Béla Cholnoky: A giant amongst aquatic scientists

28 September 2012

Bela Cholnoky, one of the world’s greatest diatomologists

A still to be published chronology of aquatic science in South Africa lists several prominent individuals as pioneers in the development of this field.  There is, however, a glaring omission, this being the name of the Hungarian diatomologist, Béla Cholnoky. Read more »

Guide to the common diatoms of South Africa now available on-line

10 July 2012

A few years ago, the second of my Diatom Assessment Protocol projects produced various tools supporting the use of diatoms for the biomonitoring of rivers and streams in South Africa.  One of the manuals was an illustrated guide to the most common diatoms found in South Africa and, given the cosmopolitan nature of the common forms, in many other countries as well.  This manual, originally produced by the Water Research Commission, went “out of print” very soon and is no longer available and the related research and development is no longer being funded.  However, given the large number of requests that my colleagues and I receive for this work, it is now available off the DHEC website.

An Illustrated Guide to Some Common Diatom Species from South Africa, by Taylor, Archibald and Harding

Diatoms prove their worth yet again

1 July 2012

The diatom Navicula tripunctata, common in eutrophic waters with a high salt content (Photo: Bill Harding)

Diatoms, microscopic algae with cell walls made of silica, have proven to be extremely valuable indicators of water quality.  They also provide indications of the presence of toxic compounds, for example misformed cells as a result of trace metal contamination.

Now, researchers in India have demonstrated that diatoms may also reflect the presence of antibiotics.  Increasing levels of antibiotics in our water resources, originating from either human or animal medications, are an increasing cause for concern.  The research found that

Changes in diatom communities in individual antibiotic treatments were either direct (chloramphenicol and potentially streptomycin) or bacteria-mediated (penicillin). According to the study, ‘streptomycin and chloramphenicol have the potential to affect diatoms directly by inhibiting their protein synthesis.’

‘These findings seem to be significant since diatoms, apart from being the basis of aquatic food-chains, are a popular tool for monitoring past and present environmental conditions and are commonly used in studies of water quality,’ [said] Samiullah Bhat, assistant professor at the Kashmir University’s department of environment.  The study suggests that investigations on the fate of antibiotics in antibiotic-polluted and natural environments must consider effects across trophic levels (position of an organism in a food chain) and particularly, diatoms, the base of aquatic food webs.

Diatoms also act as indicators of climate change and are frequently used to determine the historical nature of water quality in lakes and wetlands – this because the glass-walls of the algal cells do not disappear!

Diatom-based water quality monitoring in South-Africa. A state of the art technique in stasis.

20 June 2012

Dr Jonathan Taylor

This is an invited article prepared by Dr Jonathan Taylor, a member of the Diatom Assessment Protocol research team and Curator of the South African Diatom Collection. Read more »

South African Diatom Index published

21 May 2012

Diatoms are powerful indicators of water quality (Photo: Bill Harding)

Diatoms provide probably the most powerful biological indicator for assessing water quality in streams, rivers and wetlands.  Additionally, they can be used in a paleoecological application to determine historical conditions, an attribute which can be used in climate change assessments.  Globally, there is a massive database of information which supports the cosmopolitan use of these algae in aquatic assessments.

The culmination of a programme of research and method development, led by Bill Harding from DH Environmental Consulting, has been the formulation of the South African Diatom Index (SADI), a tool which allows the numerical composition of diatoms, collected from a specific site, to be translated into a value representing the water quality (and a whole lot of other ecological inferences as well simply not available from any other bio-indicator approaches). Read more »

Swedish scientists use diatoms to confirm the predictable.

18 December 2011

Swedish scientists have used diatoms contained in lake sediments to “date” the predictable onset of nitrogen buildup, nitrogen related to human activities that is. Diatoms provide an extremely powerful ‘forensic’ tool for this type of analysis – and the only tool, based on records of biota, that will show change in water quality over time. Read more »

Deadly diatom threatens California coast

27 November 2011

Red tides and Harmful Algal Blooms (HABs) are threatening the health of humans and marine life along the California coastline.  The San Francisco Chronicle reports today that

Marine scientists are trying to find out why previously unknown blooms of toxic algae are suddenly proliferating along the California coast, killing wildlife and increasing the risk of human sickness. Read more »

Diatoms to play a role in nanotechnology

21 October 2011

Diatoms, a miracle in glass

A scientist at the University of Bristol has been awarded £1.3 million to unlock the secrets of miniscule algae cells that have the remarkable ability to produce silica – the fundamental constituent of glass. It is hoped the findings from the research could lead to the next generation of medical imaging tools.

Dr Curnow is already working with colleagues at Bristol to study a unique set of diatom proteins that recognise and transport soluble silica. The ERC grant, one of only 30 such grants awarded to UK bioscientists in 2011, will enable him to use these proteins to create a synthetic diatom that can behave as a novel ‘nanoreactor’ for the controlled synthesis of functional silicon nanomaterials.