18 December 2017

NMU’s Center for Coastal and Marine Research have added the bbe Moldaenke PhycoProbe to their armoury of bbe chlorophyll measuring instrumentation.  The just-released PhycoProbe adds the ability to measure unbound phycocyanin, in addition to Total Chlorophyll and that from the individual groups of cyanobacteria, green algae, diatoms and cryptophytes.  The ability to measure unbound phycocyanin provides a proxy indication of cell leakage and the possible release of algal toxins into the aquatic environment.  This technology is now also incorporated in other bbe instruments such as the PhycoSens.

Prof Renzo Perissinotto (right) and Dr Gavin Rishworth (left) with their new bbe PhycoProbe.

The bbe FluoroProbe (and more recently, the bbe BenthoTorch) has been an integral part of Professor Renzo Perissinotto’s research team for the past decade and a half.  Recent projects within Prof. Perissinotto’s Shallow Water Ecosystem (SWE) SARChI Chair have focussed on three sectors, in addition to many other subsidiary projects: (1) seasonal long-term monitoring of the dynamics of Lake St. Lucia, the largest estuarine lake system in southern Africa, (2) biological community responses and baseline monitoring of proposed hydraulic fracturing of shale gas sites in the Karoo, and (3) ecosystem drivers of living peritidal stromatolites growing along the South African coastline.  In all of these ecosystems the data from the bbe Moldaenke units have provided valuable insight into ecological dynamics. Read more »

Convention on monitoring of ship ballast water nears ratification – bbe technology ready

20 May 2016

International Convention for the Control and Management of Ships’ Ballast Water and Sediments (BWM)

Invasive aquatic species present a major threat to the marine ecosystems, and shipping has been identified as a major pathway for introducing species to new environments. The problem increased as trade and traffic volume expanded over the last few decades, and in particular with the introduction of steel hulls, allowing vessels to use water instead of solid materials as ballast. The effects of the introduction of new species have in many areas of the world been devastating. Quantitative data show the rate of bio-invasions is continuing to increase at an alarming rate. As the volumes of seaborne trade continue overall to increase, the problem may not yet have reached its peak.

However, the Ballast Water Management Convention, adopted in 2004, aims to prevent the spread of harmful aquatic organisms  from one region to another, by establishing standards and procedures for the management and control of ships’ ballast water and sediments

Under the Convention, all ships in international traffic are required to manage their ballast water and sediments to a certain standard, according to a ship-specific ballast water management plan. All ships will also have to carry a ballast water record book and an international ballast water management certificate. The ballast water management standards will be phased in over a period of time. As an intermediate solution, ships should exchange ballast water mid-ocean. However, eventually most ships will need to install an on-board ballast water treatment system.
bbe’s BWM technology at the forefront of monitoring solutions

In a recent test of BWM technologies, bbe’s “10 cells” proved to be the world leader: Read more »

WWF Living Planet Report suggests 76% decline in freshwater species globally since 1970s

3 October 2014

Hellbender (Cryptobranchus alleganiensis)

Global populations of freshwater mammals, reptiles, amphibians, birds and fish have declined by 76% since the 1970s, according to a new WWF report released today.  The Living Planet Report measured the populations of 10,000 representative species across the world between 1970-2010, a method termed the Living Planet Index.

The results are startling and significant.  Global populations of all wildlife – from land, freshwater and sea – have dropped by over half since 1970 – a dramatic fall in less than one human lifetime. Read more »

Shining new light on South African rivers, estuaries and rocky shores

18 June 2014


The NMMU research team on the coast near Port Elizabeth.  Dr Miranda (left), holding the BenthoTorch, Prof Perissinotto (centre) and Jacqueline Raw (right)

A portable scientific instrument, known as the BenthoTorch (manufactured by bbe Moldaenke, Germany)  is providing a diverse group of South African aquatic scientists with the means to measure algal growth off living cells in their natural habitat.  Various algal species have adapted their nutrient uptake systems enabling them to survive in shallow water close to the shoreline, where sunlight still penetrates to the sea or river bed. This habitat is home to benthic algae, ranging from the microscopic to the enormous. Such flora play an essential role in primary production.   The ability to measure the level of algal growth, in situ, as well as the dominant groups present (the BenthoTorch can distinguish the pigment signatures of green, blue-green and diatom algae), is of enormous importance for assessing the condition and ecosystem health of streams, rivers, estuaries and coastal shorelines. Read more »

The importance of stream slime

24 April 2013

As anyone one who has slipped and fallen into a running stream knows — and that includes me, many times — those rocks aren’t just wet.

They’re slimy.

That coating is called a biofilm. And if there’s start in a riverine food chain, it’s there.

“It’s got bacteria, algae and fungi,” said Emma Rosi-Marshall, a research scientist at the Cary Institute of Ecosystems Studies in Millbrook, N.Y.

Invertebrates feed on the elements in the biofilm. Small fish feed on the invertebrates. Bigger fish, wading birds and mammals feed on those fish. A healthy biofilm means a healthy stream. Read more »

Trust me, I’m an expert …. sage advice for aquatic scientists to heed

7 February 2013

Author of this post, Martyn Kelly (Source: Bowburn Consultancy website)

A few years ago, I was involved in a project financed by the UK water industry.  The project brief was to look at the benefits of phosphorus removal on British rivers. Huge sums of money had been spent on this in recent years but there has been little obvious ecological change as a result.   One of the questions we were asked to address is whether the standards for phosphorus concentrations in UK rivers were appropriate.  However, as the project went on a second agenda came to the fore: how can we (the water industry) “sell” the idea of low phosphorus concentrations to our customers?

Diatoms were at the centre of this mini-storm: they had a strong relationship with the nutrient gradient in UK rivers and were consequently used to establish the values for the standards.  But the water industry had put their finger on a key problem: the word “diatoms” meant nothing to the general public.  They could walk beside a river, look over a bridge, see water plants, even the occasional trout.  The river did not necessarily look polluted and, for the most part, no longer had the faint odour of putrefaction hanging over it as in the past.  You might draw the line at swimming in it but, equally, you could see no particular reason why you were being asked to pay £20 per year more in order that the water company could install more sophisticated wastewater treatment facilities.  Read more »

Amphibians best ‘surrogates’ for freshwater conservation planning

5 January 2013

New research from members of the BioFresh team has found that amphibians are the best group of animals to act as ‘surrogates’ for freshwater conservation planning.

There is plenty of information out there about the patterns and predictors of biodiversity on land. But the picture gets a little murkier when we dive beneath the surface into freshwater ecosystems. While many freshwater species and ecosystems are among the most threatened in the world, global conservation priorities have, to a large extent, overlooked freshwater ecosystems. Yet without sufficient information, effective conservation planning and actions are made all that much more difficult.

Photo: WWF/TNC
Photo: WWF/TNC

That’s why BioFresh is so passionate about making as much information about freshwater ecosystems, and the creatures that live within them, as open and accessible to scientists, policy-makers and practitioners as possible. And new research from members of the BioFresh team has shed some light on the situation for freshwater ecosystems.

Their research, which appeared in the Journal of Animal Ecology in a paper titled ‘Global diversity patterns and cross-taxa convergence in freshwater ecosystems’, analysed for the first time the global distribution of five different freshwater animal groups or taxa across 819 river basins around the world. The taxa investigated were aquatic mammals, aquatic birds, freshwater fish, crayfish, and amphibians. The study looked at how environmental factors drive biodiversity patterns at the river basin level and tested the ‘convergence hypothesis’, which takes the view that the environment drives evolution in a predictable direction (i.e. the same causes should produce the same effects).

Golden Tree Frog. Photo: Creative Commons
Golden Tree Frog. Photo: Creative Commons

The study found that species richness and endemism patterns are significantly correlated and that contemporary climate, history and area are the main factors in explaining species richness and endemism patterns for most of the taxa at the river basin scale. In addition, and importantly, the research also found that amphibians, and then freshwater fish, display the highest level of congruency with other groups (taxa) of animals.

BioFresh member and co-author of the study Thierry Oberdorff, explains just why the results have potentially important implications for global freshwater conservation planning: “as most of the examined taxa display convergent patterns, one taxon can be used to predict patterns for the others.” This is significant because by using one group of animals, such as amphibians, to base conservation planning around may be the best and most cost-effective means of protecting the largest number of species, and broader freshwater ecosystems, in the resource-constrained world of conservation. And, says Oberdorff, the research suggests that ”as amphibians and fishes display the  highest levels of congruency with other taxa, these two taxa appear to be good ‘surrogate’ candidates for developing global freshwater conservation planning at the river drainage basin scale.” In addition, because amphibians are considered highly threatened and have previously been listed as potential surrogates in terrestrial ecosystems, the use of amphibians to represent spatial patterns of  biodiversity may also help unify terrestrial and freshwater conservation efforts under a common framework.

You can read more about amphibians in our 6-part amphibian special feature.

The reference for the BioFresh paper is: Tisseuil C. et al. 2012, ‘Global diversity patterns and cross-taxa convergence in freshwater ecosystems’, Journal of Animal Ecology.

(BlogPost reproduced with the kind permission of BioFresh).

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

DH Environmental’s contributions to WRC-funded science

2 September 2011

Sundowners in the Kruger Park (Photo: Linda Harding)

This week the Water Research Commission (WRC) is celebrating 40 years of existence. Since the meeting started [I did not attend], I have had – and continue to receive – several queries as to why none of the WRC projects that I have undertaken were showcased, or why I was not invited to speak on all or any of them. I guess the best place for the answer would be to ask the WRC themselves – I have my suspicions, but there it is. Read more »

The BenthoTorch for Rivers

16 May 2011

Nutrient enrichment (eutrophication) in rivers is a big problem but more difficult to measure than in lakes and dams.  This is because the algal response occurs as attached algae, on rocks or sediments or other surfaces. The quickest and easiest way to measure this is by using the bbe BenthoTorch. Read more »