Richard Greenfield

Richard Greenfield
University of Johannesburg | uj · Department of Zoology

PhD Aquatic Health

About

50
Publications
17,804
Reads
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433
Citations
Additional affiliations
August 2018 - present
University of Johannesburg
Position
  • Professor (Associate)
June 2015 - July 2018
University of Johannesburg
Position
  • Senior Lecturer
June 2004 - May 2015
University of Johannesburg
Position
  • Manager
Education
January 2001 - April 2005
University of Johannesburg
Field of study
  • Aquatic Health

Publications

Publications (50)
Article
Full-text available
Microplastics are defined as plastics smaller than 5 mm down to 0.05 mm. These plastics enter the environment and undergo certain physical changes, most notably density changes and a relative increase of surface size. Microplastics can then release or absorb toxicants from the surrounding environment. These plastics may then enter the food chain fr...
Article
Full-text available
The toxicity of pesticides to non-target organisms continues to be important in understanding the dynamic interactions between anthropogenic chemicals and ecosystem health. This study assesses biochemical markers to determine the effects that varying concentrations of atrazine (13.1–5557 µg/l) have on the freshwater shrimp, Caridina africana. Expos...
Chapter
Bioindicator species are used in biomonitoring contaminant exposure. In order to evaluate how contamination exists spatially, sessile species are the best. In addition, a good bioindicator species is common and easily sampled, presenting some responses to toxicants (biomarker responses) that can be reliably measured and show concentration dependenc...
Article
Anthropogenic activities have propelled the exploitation of natural environments, which along with climate change have resulted in salinity intrusion to freshwater ecosystems worldwide. To determine the extent the hypersalinity stressor has on freshwater ecosystems, physiological cardiac responses in the freshwater gastropod Melanoides tuberculata...
Article
The Vaal River is of considerable economic and environmental importance. It flows through five provinces within South Africa and it is subject to numerous recreational and industrial activities, which often prove detrimental to the health of the system. To determine the extent of the impact that these anthropogenic stressors have on the river syste...
Article
Microplastics are small plastic fragments that have been found around the world, however, research into microplastics in Africa and freshwater systems remains insufficient. In this study, the snapshot microplastic profile of an urban stream was assessed in the Braamfontein Spruit, located in Johannesburg the largest city in South Africa. The abunda...
Article
Full-text available
Floodplain ecosystems in Africa are under threat due to direct anthropogenic pressure and climate change. The lower Phongolo River and associated floodplain is South Africa's largest inland floodplain ecosystem and has been regulated by the Pongolapoort Dam since the 1970s. The last controlled flood release from the dam occurred in December 2014, a...
Article
Vanadium is a metal whose toxicity towards terrestrial and aquatic species has been under-reported to date. The biochemical responses of vanadium in amphibian species have not been determined. To establish the effects of vanadium (V) on exposed adult Xenopus laevis, acute and chronic exposures were conducted, and biomarker analyses were performed o...
Article
Rivers are amongst the most threatened ecosystems on the planet. They are particularly susceptible to common forms of anthropogenic influences including sewage effluent runoff and flow modification. We hypothesized that the diversity of aquatic macroinvertebrate communities from three rivers (Nyl, Mogalakwena and Limpopo) within a semi-arid region...
Article
The use of 1,1′-(2,2,2-Trichloro-1,1-ethanediyl)bis(4-chlorobenzene) (DDT) as a pesticide for the control of insects vectors responsible for the spread of many life threatening diseases was officially banned in 1972 by the United States Environmental Protection Agency (USEPA). It was banned throughout the world, in most developed countries, because...
Article
Synodontis sp. are an important source of food in many African countries including, Nigeria, South Africa, Egypt and Ghana. This is likely due to the genus being an excellent source of fat in fish‐based diets. However, there is also increased accumulation of lipophilic pollutants which can be transferred to the human population. In South Africa, Sy...
Article
Full-text available
Metal pollution in aquatic systems is considered a serious environmental issue globally due to their ability to accumulate in aquatic environments. Wetlands are vulnerable to this pollution as they are known to trap toxins, removing them from the water. Artificial mussel technology, originally developed for marine environments, was applied to this...
Article
Full-text available
This study investigated the use of an exotic fish species Oreochromis niloticus as a bio-indicator organism in active biomonitoring of Yellow Jacket and Mazowe rivers, Zimbabwe, receiving acid mine drainage from Iron Duke Mine. The Yellow Jacket River flows through Iron Duke Pyrite Mine while the Mazowe River passes through the Mazowe factory and e...
Article
The trophic status of the Ramsar-accredited Nyl River floodplain, which is stressed by sewage treatment effluents, and its ability to restore normal conditions, were assessed in 2014–2015 using diatoms as biological indicators. The Trophic Diatom Index, Specific Pollution Sensitivity Index and the Generic Diatom Index were used to characterise wate...
Poster
Full-text available
The Nyl & Mogalakwena rivers are under pressure from increased urbanisation, industrial development, mining and agriculture. Results from low flow sampling showed that the Modimolle STW is severely affecting the water quality, nutrient loads and the macroinvertebrate taxa present within these systems. Fifteen families were present at STW, while JAS...
Article
Angling fraternities widely promote catch-and-release (C&R) as a fisheries management tool. This study aimed to determine the physiological response of Africa’s premier freshwater angling species, the tigerfish Hydrocynus vittatus, to C&R angling in the Okavango Delta, Botswana. Standard angling techniques were used to collect fish, whereafter fish...
Article
Full-text available
Increased toxicity due to high metal concentrations may hinder the ecological integrity of aquatic ecosystems in sustaining life. The non-biodegradable nature of metals may result in bioaccumulation in aquatic organisms. Due to ecological and social aspects it is imperative for monitoring schemes to identify possible impacts to the systems integrit...
Article
Full-text available
Studies on metal pollution (cadmium, cobalt, chromium, copper, manganese and nickel) in South African terrestrial environments are severely lacking. Due to being relatively unaffected by industrialisation, the Thohoyandou region may provide data on natural levels of metals for use as baseline data. The House Sparrow (Passer domesticus) was chosen a...
Article
Full-text available
Unmanned Aerial Vehicle (UAV) photogrammetry has recently become a powerful tool that offers a viable alternative to traditional remote sensing systems, particularly for applications covering relatively small spatial extents. This paper presents results of a study that aimed at investigating the use of UAV photogrammetry as a tool for the mapping o...
Conference Paper
Full-text available
Heavy metals in Mopane worms from Kruger National Park Molefe M, van der Bank FH1, Greenfield R1 1African Center for DNA barcoding, University of Johannesburg, PO Box 524, Auckland Park, 2006 Abstract Between 2010 and 2012 the Food and Agriculture Organization of the United Nations (FAO) estimated that approximately 870 million people were underno...
Article
Full-text available
The use of Unmanned Arial Vehicle (UAV) photogrammetry is a valuable tool to enhance our understanding of wetlands. Accurate planning derived from this technological advancement allows for more effective management and conservation of wetland areas. This paper presents results of a study that aimed at investigating the use of UAV photogrammetry as...
Article
The use of Unmanned Arial Vehicle (UAV) photogrammetry is a valuable tool to enhance our understanding of wetlands. Accurate planning derived from this technological advancement allows for more effective management and conservation of wetland areas. This paper presents results of a study that aimed at investigating the use of UAV photogrammetry as...
Article
The practice of catch-and-release fishing has been widely promoted by angling fraternities as a fisheries manage- ment tool. The aim of this investigation was to determine the physiological response of Orange-Vaal smallmouth yellowfish, Labeobarbus aeneus, to catch-and-release angling in the Vaal River, South Africa. Fish were collected using stand...
Article
There has been a recent increase in water quality problems in South Africa. The monitoring of water resources is important for the continued management of water resources. The use of artificial mussels(AMs) as passive sampling devices in the monitoring of metals within a freshwater system was evaluated in a recent field study. Correlation testing w...
Conference Paper
Full-text available
An increase in environmental pollution, specifically heavy metal contamination, has resulted in widespread environmental degradation. Heavy metals can have adverse effects on both humans and other living organisms, thus a terrestrial bio-monitoring species in South Africa is needed. The House Sparrow (Passer domesticus), an abundant, sedentary bird...
Conference Paper
Full-text available
Exponential population growth has led to increasing amounts of polluted effluents contaminating aquatic ecosystems. An increase in nutrients from both, point and diffuse sources, leads to the eutrophication of aquatic systems, reducing ecosystem health. To ensure the sustainability of this resource, for both human and environmental use, adequate ma...
Conference Paper
Full-text available
Toxic metal contamination in aquatic ecosystems has been a major focus in recent environmental studies. The Nyl River Floodplain located downstream of where the spill took place, is the largest wetland classified as a floodplain in South Africa. The aim of the study was to determine the effect of the spill of 28000litres of sulphuric acid into the...
Poster
Full-text available
An increase in environmental pollution, specifically heavy metal contamination, has resulted in widespread environmental degradation. Heavy metals can have adverse effects in both humans and other living organisms, thus a terrestrial bio-monitoring species in South Africa is needed. The House Sparrow (Passer domesticus), an abundant, sedentary bird...
Article
Full-text available
Nineteen species of abundant gastropods were collected at Robben Island, including introduced dune snails and European brown garden snails. They were identified using morphology and DNA barcoding. It was expected that the species recorded would be similar to those from the Cape peninsula, South Africa, but we were surprised to find some exceptions:...
Article
Full-text available
Metal concentrations in Mopane worms from Phalaborwa and Shangoni sites in the Kruger National Park were determined. Metal concentrations were evaluated by inductively coupled plasma optical emission spectroscopy (ICP-OES) and ICP-MS spectrometry after microwave digestion. The results indicate a substantial bioaccumulation of metals in Mopane worms...
Article
The use of bivalves such as the brown mussel (Perna perna) and the black mussel (Choromytilus meridionalis) is common in the study of marine pollution and the effect of these pollutants on ecosystems and are important in both economic and ecological roles. Namibian marine ecosystems are threatened by pollution from mining, commercial fishing and po...
Article
Full-text available
The genus Oxystele, a member of the highly diverse marine gastropod superfamily Trochoidea, is endemic to southern Africa. Members of the genus include some of the most abundant molluscs on southern African shores and are important components of littoral biodiversity in rocky intertidal habitats. Species delimitation within the genus is still contr...
Article
Full-text available
The genus Oxystele, a member of the highly diverse marine gastropod superfamily Trochoidea, is endemic to southern Africa. Members of the genus include some of the most abundant molluscs on southern African shores and are important components of littoral biodiversity in rocky intertidal habitats. Species delimitation within the genus is still contr...
Article
Full-text available
INTRODUCTION Biodiversity is currently lost at an alarming rate (Pimm et al. 1995), and species decline is predicted to sustain over time (Mace et al. 2005). This loss is the result of multiple pressures on biodiversity, including human activities and climate change. Humans drive species loss through over-exploitation, pollution, introduction of sp...
Article
Full-text available
The Nyl River floodplain, a Ramsar site that provides habitat for a number of endangered species, is one of the jewels in the arid Limpopo province and thus its conservation and protection are vitally important. Very little work has been done on assessing its water quality and no data have been published on the metal concentrations found in this va...
Article
Full-text available
Die Mollusca is die tweede grootste dierfilum. Dit sluit meer as 35 000 fossiel en 100 000 lewendespesies in. Die doel van hierdie studie was om ‘n opname te maak van die mosselkrewels, inheemse en uitlandse slakspesies op die eiland.
Article
Full-text available
The Nyl River floodplain, a Ramsar site that provides habitat for a number of endangered species, is one of the jewels in the arid Limpopo province and thus its conservation and protection are vitally important. Very little work has been done on assessing its water quality and no data have been published on the metal concentrations found in this va...
Book
Full-text available
Freshwater angling activities have become an important recreational activity for people around the globe, bolstering both regional and national economies. A portion of the captured fish is sometimes kept by anglers, but many of them immediately release all of the fish that they catch back into their natural environment. This practice of “catch-and-...
Article
Richards Bay Harbour is South Africa's premier bulk cargo port. It was constructed in the Mhlathuze estuary in 1976 and over the past 34 years has become South Africa's most modern and largest cargo handling port. Although no official monitoring programme is in progress various studies by different groups have provided relevant data with respect to...
Article
Full-text available
Because water quantity and quality are of great importance in the arid Limpopo province, the bacterial content of water in the Nyl River System and its possible origins were assessed at five sites. Quarterly surveys took place between April 2001 and July 2002 and the water was analysed for bacterial counts using standard procedures. Heterotrophic p...
Article
Full-text available
Although critical in catch-and-release angling, no data are available on angling-induced stress in African gamefish. Blood lactate levels were used as a biomarker for angling-induced metabolic stress in tigerfish caught by angling in the Okavango Delta, Botswana. Blood was drawn and analysed for blood lactate from 66 anaesthetised fish. The landing...
Article
Recent work in the field of parasitology has drawn attention to the application of parasites as pollution-accumulation indicators, particularly cestodes. A discrepancy in metal concentrations within cestode posterior and anterior tissue has led researchers to attribute this phenomenon to metals binding to the shells of their eggs. Thus, the objecti...
Article
Full-text available
The importance o� wetland management and conservation is becoming more and more prevalent in the world today. It is thus important to determine baseline contamination values �or wetlands to assist in making in�ormed management decisions. Sediment from the Nyl River flood plain in the dry Limpopo Province was analysed using sequential extraction and...
Technical Report
Full-text available
EXECUTIVE SUMMARY Water in South Africa is a critically important natural resource. The Department of Water Affairs and Forestry list it as one of the most limiting resources in South Africa. South Africa is a semi-arid to arid region, receiving only an average of 500 mm of rain per annum, which is only 60% of the world average. Sixty five percent...

Questions

Question (1)
Question
Our Laboratory was recently affected by smoke damage after a fire. It is all covered in a thick layer of soot inside and out. Would it be advisible to replace the glassware or is there a way of making sure it is clean so as not to affect our results?

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Projects

Projects (8)
Archived project
1) The determination of spatial and temporal differences in metal contaminants in water and sediment from the origin of the Klein Nyl River (Modimolle) to the Moorddrift Dam (Mokopane). 2) To compare water and sediment quality conditions in the system now to those found 10 years ago in a study by Vlok et al. (2006).