Risks Induced by Pesticides on Fish Reproduction (original) (raw)
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Environmental Biology of Fishes, 1993
Anabas testudineus were treated with non lethal levels of metacid-50 (0.106 ppb) and carbaryl(1.66 ppm) for 90 days covering the pre-spawning and spawning phases of the annual reproductive cycle. The main purpose of the present work was to identify the effects of metacid-50 and carbaryl on the gonado somatic index (GSI) and ovarian and plasma estrogen level. There was no alteration in GSI until 15 days, initiating the inhibition on day 20 which further intensified from 20 to 90 days of exposure. Plasma and ovarian estrogen level significantly increased up to 15 days of exposure followed by a decline till the end of the experiment. It is noteworthy that the effect of pesticides on GSI is reflected in the ovarian estrogen level. This highlights the fact that at short-term exposures the nonlethal levels of pesticides have no inhibitory effect while at long-term exposure, the pesticides have potent inhibitory effect on the reproduction of fish.
Overview of pesticide toxicity in fish
Advances in Environmental Biology, 2012
Modern agricultural practices result in indiscriminate use of various pesticides, which usually enter into the aquatic environment. The use of pesticides in the field has the potential to change the aquatic medium, affecting the tolerance limit of aquatic fauna and flora, as well as creating danger to the ecosystem. These pesticides adversely affect the non-target organisms, especially fish. The present study discusses among other issues, the toxic effects of pesticides on aquatic life with emphasis on fish and the public health implication.
Distribution of Endocrine-Disrupting Pesticides in Water and Fish from the Oder River, Poland
Acta Ichthyologica Et Piscatoria, 2010
Background. Organochlorine pesticides (OCPs), which act in a similar way to natural hormones, lead to disorders of the endocrine system in animals and humans (endocrine disruptors). Among food products, fish are considered to be the main source of these compounds in the human diet, posing a health risk to consumers. The aim of this study was to determine concentrations in fish and their environment of certain organochlorine pesticides in fish and their environment and to estimate daily intakes (EDI) of individual pesticides from the fish examined. Materials and Methods. Analyses aimed at detecting the pesticides (OCPs: α-, β-, γ-HCH, heptachlor, heptachlor epoxide, aldrin, dieldrin, and endrin) included samples of water taken from the lower stretch of the Oder River and three fish species, which are commonly harvested in that area. Quantitative analyses were carried out using the Capillary Gas Chromatography/Mass Spectrometry method in a GC MSD HP 6890/5973 apparatus. Results. The study found that concentrations of OCPs in fish gonads were significantly higher than in the muscle tissue. The dominant pesticide compound in gonads of roach and bream was γ-HCH, whilst β-HCH predominated in the muscle tissues of those fishes. Endrin, on the other hand was the major pesticide in the muscle tissue of ide. Mean concentrations of OCPs in the gonads ranged from 0.385 to 0.544 ng • g-1 wet weight (w.w.) for α-HCH, 0.745 to 0.832 ng • g-1 w.w. for γ-HCH, 0.479 to 0.576 ng • g-1 w.w. for dieldrin, and 0.381 to 0.684 ng • g-1 w.w. for endrin. Concentrations of the studied compounds in the water taken from the Oder River followed the order: endrin > γ-HCH > α-HCH > dieldrin > β-HCH > heptachlor ≈ aldrin > heptachlor epoxide. The highest log BCF was obtained for fish gonads and ranged from 1.5 (endrin) to 3.4 (heptachlor epoxide). Estimated daily intakes (EDI) varied from 0.0014% to 0.097% of the acceptable daily intake (ADI). Conclusion. This study revealed no direct risk linked to the consumption of fish captured from the study area. However, from the ecological aspect, the accumulation of organochlorine residues in fish gonads has been considered a dangerous phenomenon, as this may result in decreased reproduction of fish and other aquatic organisms, potentially leading to their extinction.
Endocrine Toxicants and Reproductive Success in Fish
Human and Ecological Risk Assessment: An International Journal, 2001
There is compelling evidence on a global scale for compromised growth and reproduction, altered development, and abnormal behaviour in feral fish that can be correlated or in some cases causally linked with exposure to endocrine disrupting chemicals (EDCs). Attributing cause and effect relationships for EDCs is a specific challenge for studies with feral fish as many factors including food availability, disease, competition and loss of habitat also affect reproduction and development. Even in cases where there are physiological responses of fish exposed to EDCs (e.g., changes in reproductive hormone titres, vitellogenin levels), the utility of these measures in extrapolating to whole animal reproductive or developmental outcomes is often limited. Although fish differ from other vertebrates in certain aspects of their endocrinology, there is little evidence that fish are more sensitive to the effects of EDCs. Therefore, to address why endocrine disruption seems so widespread in fish, it is necessary to consider aspects of fish physiology and their environment that may increase their exposure to EDCs. Dependence on aquatic respiration, strategies for iono-osmotic regulation, and maternal transfer of contaminants to eggs creates additional avenues by which fish are exposed to EDCs. This paper provides an overview of responses observed in feral fish populations that have been attributed to EDCs and illustrates many of the factors that need consideration in evaluating the risks posed by these chemicals.
2012
The effects of sublethal concentrations of the organophosphate pesticide Dichlorvos (Neon) (0.65 mg/l, 0.90 mg/l and 1.17 mg/l) on the gonadosomatic index of the fish, Cyprinus carpio communis was studied. The Ganadosomatic index decreased with the increase in concentration, whereas it increased with increase in exposure at all concentrations. It may also be noted that the reduction in GSI values was maximum at highest concentrations of the pesticide in series. Ovaries of the Dichlorvos treated fish showed histomorphological disorders. Furthermore, the reduced GSI was found directly proportional to the pesticide concentration and duration of exposure.
An overview of the pesticides’ impacts on fishes and humans
International Journal of Aquatic Biology, 2021
Agrochemicals, also known as pesticides include nematicides, molluscicides, rodenticides, herbicides, fungicides and insecticides, can control pests, weeds, fungi, rodents, etc. The accumulation of pesticides in the food chain and water has harmful effects on humans and animals. Despite the advantages provided by pesticides, aquatic organisms and human health are affected as the results of continuous usage of pesticides and issues of building up of chemical substances in aquatic organisms, such as fish. Pesticides must be lethal to the targeted species without any effect on non-targeted ones. Pesticides have harmful effects on the nervous system. Other pesticides are known to be carcinogenic substances. This review discussed the effects of pesticides on the immune system, protein, chromosomes, behavior, enzymes, growth, bioaccumulation, genotoxicity and changes in blood biochemical parameters of fish and humans and suggested some possible ways of mitigating such effects.
Ecotoxicology and Environmental Safety, 2014
Pesticides like malathion have the potential to disrupt development and reproduction of aquatic organisms including fishes. To investigate the likely consequences of malathion exposure at low doses in juvenile catfish, Clarias batrachus, we studied the expression pattern of genes encoding certain transcription factors, activin A, sex steroid or orphan nuclear receptors and steroidogenic enzymes which are known to be involved in gonadal development along with histological changes. To compare further, we also analyzed certain brain specific genes related to gonadal axis. Fifty days post hatch catfish fingerlings were exposed continuously to 1 and 10 mg/L of malathion for 21 days. Results from these experiments indicated that transcript levels of various genes were altered by the treatments, which may further affect the gonadal development either directly or indirectly through brain. Histological analysis revealed slow progression of spermatogenesis in testis, while in ovary, the oil droplet oocytes were found to be higher after treatment (10 mg/L). Our findings revealed that the exposure of malathion, even at low doses, hinder or modulate early gonadal development differentially by targeting gene expression pattern of transcription factors, activin A, sex steroid or orphan nuclear receptors and steroidogenic enzymes with an evidence on histological changes. Further, some of the genes showed differential expression at the level of brain in male and female sex after the exposure of malathion.
Implication of Pesticides Usage on Freshwater Fish: A Review
FUDMA JOURNAL OF SCIENCES, 2021
Pesticides play a significant role in improving food production through control against harmful pests with low labour and efforts while on the other hand are regarded as aquatic pollutants. These toxicants persist in aquatic environment and cause harmful effects to non- target organisms including fish. The development of pesticide tolerant species led to the need and use of varieties of pesticides with the risk of exposure to many compartments including water. Many pesticides have been proscribed for agricultural purposes by the regulatory agencies such as WHO (2020). However, It is unfortunate that many of these are sold in Nigeria or donated by donor agencies. The donated pesticides often become “obsolete” while in stock due to poor logistics and delays in receiving them at the point of need. The review on the classification, bioavailability, biotransformation, the direct and indirect effects of pesticides on freshwater fish was carried out. Biomarkers of pesticides toxicity t...
Studies on Pesticides Residues in Fish in Menofia Governorate
A total of 90 samples of fish (each 45 samples of Tilapia Nilotica and 45Claris Lazera) were collected from EL-Bagoria canal, EL-Menofy drainage and Bahr Shibin in Menofia governorate and analyzed to detect and determine Organochlorine (DDT, aldrin and dieldrin) and organophosphorus (diazinon, Malathion and chlorpyrifos). Organochlorine and organophosphorus pesticides could not be detected in Bahr Shibin while mean value of DDT in Tilapia Nilotica from EL-Bagoria canal was 0.37±0.09, aldrin was 0.33±0.03and dieldrin was 0.50±0.20 while in EL-Menofy drainage mean level of DDT was 0.34±0.07, aldrin was 0.40±0.08 and dieldrin was0.40±0.13. While in Claris Lazera samples from EL-Bagoria canal mean level of DDT was 0.40±0.46, aldrin was 0.25±0.07and dieldrin was 0.34±0.08 while from EL-Menofy drainage mean value of DDT was 0.27±0.05, aldrin was 0.30±0.07 and dieldrin was 0.48±0.10. Concerning organophosphorus compounds, no diazinon was recorded in Tilapia Nilotica from EL-Bagoria while mean level of Malathion from EL-Bagoria was 5.50±2.0, the mean level of chlorpyrifos was 5.0±1.66.whie from EL-Menofy drainage the mean level of diazinon was 3.33±0.65, the mean level of Malathion was 4.98±1.22 ,the mean level of chlorpyrifos was 3.0±0.71.while in Claris Lazera samples from EL-Bagoria there were no diazinon , no Malathion no chlorpyrifos while from EL-Menofy drainage ,the mean level of diazinon was 6.8± 1.42 , the mean level of Malathion was 4..64±0.81 and the mean level of chlorpyrifos was 4.0±0.96. Pesticides are one the main contaminants of water sources that act as the natural environment of fish. On the other hand, fish contaminated by pesticides either directly by gills breathing or indirectly through contamination of feeding items, so it is very important to analyze fish samples to detect to what extent the rate of accumulation of pesticides residues in fish flesh and organs.