Preliminary assessment of contaminants in the sediment and organisms of the Swartkops Estuary, South Africa

Nel, L.; Strydom, Nadine A.; Bouwman, Hindrik

doi:10.1016/j.marpolbul.2015.11.015

Cited by 39 publications

(16 citation statements)

References 26 publications

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“…In contrast, bioaccumulation of Al and Se was examined much less frequently, or in the case of Ga not at all. Metal bioaccumulation, however, does not always reflect environmental metal concentrations [66, 67, 83, 84], and can vary with fish species [67, 74, 82, 85–87], tissue [66, 67, 73, 86], and life history stage [70, 82], with exposure pathways [82, 88, 89], with season [90, 91], and can be influenced by metal speciation and bioavailability [73, 85, 92]. Hence, when using biomarkers to assess fish health, metal bioaccumulation should be used in conjunction with other biomarkers to indicate whether biological responses are related to bioaccumulation.…”

Section: Resultsmentioning

confidence: 99%

A protocol for identifying suitable biomarkers to assess fish health: A systematic review

2017

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BackgroundBiomarkers have been used extensively to provide the connection between external levels of contaminant exposure, internal levels of tissue contamination, and early adverse effects in organisms.ObjectivesTo present a three-step protocol for identifying suitable biomarkers to assess fish health in coastal and marine ecosystems, using Gladstone Harbour (Australia) as a case study.MethodsPrior to applying our protocol, clear working definitions for biomarkers were developed to ensure consistency with the global literature on fish health assessment. First, contaminants of concern were identified based on the presence of point and diffuse sources of pollution and available monitoring data for the ecosystem of interest. Second, suitable fish species were identified using fisheries dependent and independent data, and prioritised based on potential pathways of exposure to the contaminants of concern. Finally, a systematic and critical literature review was conducted on the use of biomarkers to assess the health of fish exposed to the contaminants of concern.Results/DiscussionWe present clear working definitions for bioaccumulation markers, biomarkers of exposure, biomarkers of effect and biomarkers of susceptibility. Based on emission and concentration information, seven metals were identified as contaminants of concern for Gladstone Harbour. Twenty out of 232 fish species were abundant enough to be potentially suitable for biomarker studies; five of these were prioritised based on potential pathways of exposure and susceptibility to metals. The literature search on biomarkers yielded 5,035 articles, of which 151met the inclusion criteria. Based on our review, the most suitable biomarkers include bioaccumulation markers, biomarkers of exposure (CYP1A, EROD, SOD, LPOX, HSP, MT, DNA strand breaks, micronuclei, apoptosis), and biomarkers of effect (histopathology, TAG:ST).ConclusionOur protocol outlines a clear pathway to identify suitable biomarkers to assess fish health in coastal and marine ecosystems, which can be applied to biomarker studies in aquatic ecosystems around the world.

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Section: Resultsmentioning

confidence: 99%

A protocol for identifying suitable biomarkers to assess fish health: A systematic review

2017

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“…Screening of river mouths and harbors around the coast of South Africa showed estrogenic and antiandrogenic activity ( Truter et al 2015 ). High concentrations of arsenic, lead, mercury, and cadmium were found in the juvenile stages of the popular angling fishes Lichia amia , Argyrosomus japonicus , and Pomadasys commersonnii ( Nel et al 2015 ) in a South African estuary; both cadmium and arsenic were detected at levels that exceed international food quality guidelines.…”

Section: Edc Exposures: Impact On Wildlife Health In Africamentioning

confidence: 96%

Endocrine Disruptors and Health Effects in Africa: A Call for Action

Bornman

Aneck-Hahn

Jager

et al. 2017

Environ Health Perspect

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Background:Africa faces a number of unique environmental challenges. Unfortunately, it lacks the infrastructure needed to support the comprehensive environmental studies that could provide the scientific basis to inform environmental policies. There are a number of known sources of endocrine-disrupting chemicals (EDCs) and other hazardous chemicals in Africa. However, a coordinated approach to identify and monitor these contaminants and to develop strategies for public health interventions has not yet been made.Objectives:This commentary summarizes the scientific evidence presented by experts at the First African Endocrine Disruptors meeting. We describe a “call to action” to utilize the available scientific knowledge to address the impact of EDCs on human and wildlife health in Africa.Discussion:We identify existing knowledge gaps about exposures to EDCs in Africa and describe how well-designed research strategies are needed to address these gaps. A lack of resources for research and a lag in policy implementation slows down intervention strategies and poses a challenge to advancing future health in Africa.Conclusion:To address the many challenges posed by EDCs, we argue that Africans should take the lead in prioritization and evaluation of environmental hazards, including EDCs. We recommend the institution of education and training programs for chemical users, adoption of the precautionary principle, establishment of biomonitoring programs, and funding of community-based epidemiology and wildlife research programs led and funded by African institutes and private companies. https://doi.org/10.1289/EHP1774

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“…Studies agree that the rate of metal accumulation has increased throughout the Swartkops Estuary, in some cases more than 100% for Cr, Mn, Pb and Zn (Binning and Baird, 2001). In 2014 high concentrations were found in the juveniles of popular angling fish, selected invertebrates and in the eggs of gull, exceeding the international food quality guidelines, where applicable (Nel et al, 2015). Other than fishing, the estuary has important recreational and ecological importance, providing numerous essential ecosystem services originating from the diverse salt marsh and seagrass habitats.…”

Section: Introductionmentioning

confidence: 92%

Rhizosediments of Salicornia tegetaria Indicate Metal Contamination in the Intertidal Estuary Zone

Nel

Rubidge

Adams

et al. 2020

Front. Environ. Sci.

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Metal pollution is a well-known anthropogenic impact of highly developed estuaries, with dire consequences to the ecosystem. This study investigated the metal concentrations (Al, Cr, Cu, Fe, Mn, Ni, Pb, Zn) in the sediment colonized by Salicornia tegetaria, a dominant salt marsh plant in the lower intertidal zone of the Swartkops Estuary. The samples were collected at five sites along the banks of the middle and lower reaches of the estuary, and analyzed using an Inductively Coupled Plasma-Optical Emission Spectrometer. Metal contamination was determined using established normalized baseline models. It was found that all the sites contained metal enrichment, with the estuary mouth experiencing the least enrichment. Salicornia tegetaria holds a substantial amount of anomalous metals within its rhizosediment-providing a valuable ecosystem service to a highly developed Swartkops Estuary.

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Preliminary assessment of contaminants in the sediment and organisms of the Swartkops Estuary, South Africa

Cited by 39 publications

References 26 publications

A protocol for identifying suitable biomarkers to assess fish health: A systematic review

A protocol for identifying suitable biomarkers to assess fish health: A systematic review

Endocrine Disruptors and Health Effects in Africa: A Call for Action

Rhizosediments of Salicornia tegetaria Indicate Metal Contamination in the Intertidal Estuary Zone

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