Developmental alterations and endocrine-disruptive responses in farmed Nile crocodiles ( Crocodylus niloticus ) exposed to contaminants from the Crocodile River, South Africa

Arukwe, Augustine; Myburgh, Jan G.; Langberg, Håkon Austad; Adeogun, Aina O.; Braa, Idunn Godal; Moeder, Monika; Schlenk, Daniel; Crago, Jordan; Regoli, Francesco; Botha, Charl P.

doi:10.1016/j.aquatox.2015.12.027

Cited by 15 publications

(17 citation statements)

References 52 publications

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“…A study on proteomic responses of Carassius auratus exposed to a mixture of pesticides (Gandar et al 2017), which included the metabolite desethyl atrazine (but not the parent atrazine), was excluded. A study on the effects of a mixture of chemicals (including atrazine) on farmed crocodiles (Crocodylus niloticus) (Arukwe et al 2016) was excluded.…”

Section: Methodsmentioning

confidence: 99%

Effects of atrazine on fish, amphibians, and reptiles: update of the analysis based on quantitative weight of evidence

Hanson

Solomon

Kraak

et al. 2019

Critical Reviews in Toxicology

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Quantitative weight of evidence (QWoE) provides a framework and process for evaluating different toxicological studies based on quality and relevance of the results. This framework allows for data from these studies to be combined in separate lines of evidence to address causality, and relevance to environmental risks. In 2014, such a QWoE that examined the body of available company reports and peer reviewed literature regarding the effects of the herbicide atrazine on fish, amphibians, and reptiles was published. Since that time, new studies have been conducted and/or published. One of the advantages of the QWoE framework is that additional information can be added as it becomes available. Thus, these new studies were evaluated in the same manner as previously and the new data incorporated into the existing QWoE. As before, the new updated QWoE was based on the same process of objective scoring of individual studies with respect to the quality of the methods and the relevance of individual responses to the apical endpoints of survival, growth, development, and reproduction. These new data did not identify new responses or indicate any relevant effects of atrazine. The new updated QWoE analysis concluded that atrazine does not adversely affect fish, amphibians, and reptiles, at environmentally relevant concentrations (<100 mg atrazine/L), which is consistent with the previous conclusions. These new studies and data are discussed in this paper and the accompanying supplement information provides detailed and transparent information to support these conclusions.

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Section: Methodsmentioning

confidence: 99%

Effects of atrazine on fish, amphibians, and reptiles: update of the analysis based on quantitative weight of evidence

Hanson

Solomon

Kraak

et al. 2019

Critical Reviews in Toxicology

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“…In the second study, markers of endocrine disruption were studied using polymerase chain reaction, enzyme immunoassays, and other biochemical methods [131]. The results showed that these crocodiles "exhibited responses to anthropogenic aquatic contaminants with potentially relevant consequences on key reproductive and endocrine pathways," with strong relationships to PAH concentrations for several indicators of endocrine disruption [131]. One will note that the phenomenon of exposure to anthropogenic contamination under captive conditions was previously discussed for captive sea turtles [105].…”

Section: Crocodiliamentioning

confidence: 97%

“…Very few studies have focused on crocodile exposure to PAHs. To date, 2 known studies (with some overlap in authorship) on this subject were available [131,131]. Together, these 2 studies describe different indicators of exposure to pollution for captive farmed-raised C. niloticus (Nile crocodiles).…”

Section: Crocodiliamentioning

confidence: 99%

Reptilian exposure to polycyclic aromatic hydrocarbons and associated effects

Zychowski

Godard-Codding

2016

Enviro Toxic and Chemistry

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Reptiles are an underrepresented taxon in ecotoxicological literature, and the means by which toxicants play a role in population declines are only partially understood. Among the contaminants of interest for reptiles are polycyclic aromatic hydrocarbons (PAHs), a class of organic compounds that is already a concern for numerous other taxa. The objectives of the present review are to summarize the existing literature on reptilian exposure to PAHs and synthesize general conclusions, to identify knowledge gaps within this niche of research, and to suggest future directions for research. Results confirm a relative scarcity of information on reptilian exposure to PAHs, although research continues to grow, particularly after significant contamination events. The orders Testudines and Squamata are better represented than the orders Crocodilia and Rhynchocephalia. For the taxonomic orders with relevant literature (all but Rhynchocephalia), some species are more frequently represented than others. Few studies establish solid cause-effect relationships after reptilian exposure to PAHs, and many more studies are suggestive of effect or increased risk of effect. Despite the scarcity of information in this area, researchers have already employed a wide variety of approaches to address PAH-related questions for reptiles, including molecular techniques, modeling, and field surveys. As more research is completed, a thoughtful interpretation of available and emerging data is necessary to make the most effective use of this information. Environ Toxicol Chem 2017;36:25-35. #

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“…Although many studies quantified agrochemicals in South African water ( Amdany et al , 2014 ; Odendaal et al , 2015 ; Wooding et al , 2017 ; Adeyinka et al , 2019 ; Ojemaye et al , 2020 ), few studies have also investigated the associated ED effects ( Barnhoorn et al , 2010 ; Arukwe et al , 2016 ). Most studies that evaluated ED of agrochemicals in South Africa were laboratory-based using in vitro or in vivo bioassays of single active ingredients or pesticide mixtures ( Archer and Van Wyk, 2015 ; Rimayi et al , 2018b ).…”

Section: Introductionmentioning

confidence: 99%

Agrochemicals in freshwater systems and their potential as endocrine disrupting chemicals: A South African context

Horak

Horn

Pieters

2021

Environmental Pollution

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South Africa is the largest agrochemical user in sub-Saharan Africa, with over 3 000 registered pesticide products. Although they reduce crop losses, these chemicals reach non-target aquatic environments via leaching, spray drift or run-off. In this review, attention is paid to legacy and current-use pesticides reported in literature for the freshwater environment of South Africa and to the extent these are linked to endocrine disruption. Although banned, residues of many legacy organochlorine pesticides (endosulfan and dichlorodiphenyltrichloroethane (DDT)) are still detected in South African watercourses and wildlife. Several current-use pesticides (triazine herbicides, glyphosate-based herbicides, 2,4-dichlorophenoxyacetic acid (2,4-D) and chlorpyrifos) have also been reported. Agrochemicals can interfere with normal hormone function of non-target organism leading to various endocrine disrupting (ED) effects: intersex, reduced spermatogenesis, asymmetric urogenital papillae, testicular lesions and infertile eggs. Although studies investigating the occurrence of agrochemicals and/or ED effects in freshwater aquatic environments in South Africa have increased, few studies determined both the levels of agricultural pesticides present and associated ED effects. The majority of studies conducted are either laboratory-based employing in vitro or in vivo bioassays to determine ED effects of agrochemicals or studies that investigate environmental concentrations of pesticides. However, a combined approach of bioassays and chemical screening will provide a more comprehensive overview of agrochemical pollution of water systems in South Africa and the risks associated with long-term chronic exposure.

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Developmental alterations and endocrine-disruptive responses in farmed Nile crocodiles ( Crocodylus niloticus ) exposed to contaminants from the Crocodile River, South Africa

Cited by 15 publications

References 52 publications

Effects of atrazine on fish, amphibians, and reptiles: update of the analysis based on quantitative weight of evidence

Effects of atrazine on fish, amphibians, and reptiles: update of the analysis based on quantitative weight of evidence

Reptilian exposure to polycyclic aromatic hydrocarbons and associated effects

Agrochemicals in freshwater systems and their potential as endocrine disrupting chemicals: A South African context

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