Book ChapterDOI
Influence of pollution on parasites of aquatic animals.
TLDR
While published information suggests more than a casual connection between fish parasites and pollution, further research is needed to establish the cause-and-effect relationship and at the same time take cognizance of histopathological effects of the toxic agents and their concentrations in water.Abstract:
We have tried to draw attention to an increasing body of evidence (from several publications) that parasites of fish might be useful indicators of pollution. Several types of pollutants, including domestic sewage, pesticides, polychlorinated biphenyls, heavy metals, pulp and paper effluents, petroleum aromatic hydrocarbons, acid rain, and others, are known to affect aquatic animals. Many of the latter are parasitized and, under natural environmental conditions, most fish parasites are believed to cause little or no harm. However, chronic exposure to pollutants over a period of time causes biochemical, physiological and behavioural host changes that ultimately can influence the prevalence and intensity of parasitism. Some of these changes include host nutrition, growth and reproduction. Macroscopic lesions might not always be apparent, but subtle disorders in several specific tissues and organs might occur. Pollutants might promote increased parasitism in aquatic animals, especially fish, by impairing the host's immune response or favouring the survival and reproduction of the intermediate hosts. Alternatively, decreased parasitism might ensue through toxicity of the pollutant to free-living stages and intermediate hosts or by alteration of the host's physiology. Experimental studies indicate that the numbers of ectoparasites such as trichodinid ciliates and monogeneans increase significantly on the gills following exposure to a pollutant, and this is supported by field data on other ciliates and monogeneans where evidence of pollution has been clearly demonstrated. There is also evidence that endoparasitic protozoons, such as myxozoons, microsporans and haematozoons, all of which are capable of proliferating in their hosts, increase substantially in prevalence and intensity when interacting with pollutants. The period of patency might also be prolonged in haematozoan infections. Most reports of pollution effects on endoparasites suggest increased parasitism in fish hosts. This also applies to fish living in areas which receive thermal effluents. Parasites might in turn enhance their hosts' susceptibility to pollutants, and information in support of this view is accumulating. Finally, immunosuppression represents one of the underlying mechanisms influencing increased parasitism. Thus, while published information suggests more than a casual connection between fish parasites and pollution, further research is needed to establish the cause-and-effect relationship and at the same time take cognizance of histopathological effects of the toxic agents and their concentrations in water. Areas for future research are recommended.read more
Citations
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Journal ArticleDOI
Review of Antimicrobial Resistance in the Environment and Its Relevance to Environmental Regulators
TL;DR: It is argued that the lack of environment-facing mitigation actions included in existing AMR action plans is likely a function of the authors' poor fundamental understanding of many of the key issues and the science to inform policy is lacking and this needs to be addressed.
Journal ArticleDOI
Environmental parasitology: What can parasites tell us about human impacts on the environment?
TL;DR: How parasite ecologists have used and can use parasites to assess environmental quality is discussed, suggesting that information on parasites can indicate anthropogenic impacts.
Journal ArticleDOI
Pollution biomarkers in estuarine animals: critical review and new perspectives.
José Maria Monserrat,José Maria Monserrat,Pablo Elias Martinez,Pablo Elias Martinez,Laura A. Geracitano,Lílian Lund Amado,Camila de Martinez Gaspar Martins,Grasiela Lopes Leães Pinho,Isabel Soares Chaves,Marlize Ferreira-Cravo,Juliane Ventura-Lima,Adalto Bianchini,Adalto Bianchini +12 more
TL;DR: In this review, recent developments in monitoring toxicological responses in estuarine animals are analyzed, considering the biomarker responses to different classes of pollutants.
Journal ArticleDOI
Ecotoxicology and innate immunity in fish
TL;DR: Advances in basic knowledge of fish innate immunity should lead to improvements in monitoring fish health and predicting the impact of toxicants on fish populations, which is a fundamental ecotoxicological goal.
Journal ArticleDOI
Parasites of the superorganism: Are they indicators of ecosystem health?
TL;DR: The challenge for parasitology is to convince resource managers and fellow scientists that parasites are a natural part of all ecosystems, each species being a potentially useful information unit, and that healthy ecosystems have healthy parasites.
References
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Journal ArticleDOI
Fish Gill Structural Changes Induced by Toxicants and Other Irritants: A Statistical Review
TL;DR: Here I quantitatively review the literature on how fish gill morphology is affected by chemical and physical irritants in the surrounding water.
Journal ArticleDOI
The effects of environmental stress on outbreaks of infectious diseases of fishes
TL;DR: Examples taken from the literature were selected and reviewed to show the coincidence of infectious diseases with stress caused by temperature, eutrophication, sewage, metabolic products of fishes, industrial pollution, and pesticides.
Journal ArticleDOI
Single nutrients and immunity
TL;DR: Major gaps currently exist in knowledge about single nutrient deficits or excesses in terms of their effects on specific functional components of the immune system, and a workshop was sponsored by the Food and Nutrition Board of the American Medical Association to emphasize the diversity of the subject, the magnitude of unsolved problems, and the complexity of interrelationships requiring consideration.
Nutrition and immunity.
TL;DR: Some of the consequences of nutrient deficiencies are described, but more importantly foods that help maintain or balance the immune response by the +% T cell are discussed.
Journal ArticleDOI
Fish kill at low pH in a Norwegian river.
Helge Leivestad,I. P. Muniz +1 more
TL;DR: The decline in freshwater fish populations in parts of southern Norway is associated with increasing acidity in rivers and lakes, and the salmon has been eliminated from many rivers, and hundreds of lakes have lost their trout populations.