Ecological Risks Due to Immunotoxicological Effects on Aquatic Organisms

Abstract

The immunotoxic effects of some anthropogenic pollutants on aquatic organisms are among the causes of concern over the presence of these pollutants in the marine environment. The immune system is part of an organism’s biological defense necessarily for homeostasis. Thus, the immunotoxicological impacts on aquatic organisms are important to understand the effects of pollutant chemicals in the aquatic ecosystem. When aquatic organisms are exposed to pollutant chemicals with immunotoxicity, it results in poor health. In addition, aquatic organisms are exposed to pathogenic bacteria, viruses, parasites, and fungi. Exposure to pollutant chemicals has reportedly caused aquatic organisms to show various immunotoxic symptoms such as histological changes of lymphoid tissue, changes of immune functionality and the distribution of immune cells, and changes in the resistance of organisms to infection by pathogens. Alterations of immune systems by contaminants can therefore lead to the deaths of individual organisms, increase the general risk of infections by pathogens, and probably decrease the populations of some species. This review introduced the immunotoxicological impact of pollutant chemicals in aquatic organisms, including invertebrates, fish, amphibians, and marine mammals; described typical biomarkers used in aquatic immunotoxicological studies; and then, discussed the current issues on ecological risk assessment and how to address ecological risk assessment through immunotoxicology. Moreover, the usefulness of the population growth rate to estimate the immunotoxicological impact of pollution chemicals was proposed.

Larger Common River Frogs (Amietia delalandii) have Fewer and Shorter Tissue Microplastic Fibres than Smaller Frogs

“…MPs have the potential to bioaccumulate as the tadpoles mature. Bioaccumulation of MPs in the intestinal wall can induce mechanical stress (Bonfanti et al 2021 ) or immunosuppression causing an increased vulnerability to pathogens (Kataoka and Kashiwada 2021 ). False satiety caused by MPs in the gut has similarly been seen in various animals including earthworms (Zhang et al 2022 ), lobsters (Welden and Cowie 2016 ), and turtles (Santos et al 2020 ).…”

Epigenetic Modulations for Prevention of Infectious Diseases in Shrimp Aquaculture

“…Additionally, fluctuations in environmental conditions, such as temperature and salinity, exert significant impacts on shrimp’s immune and physiological functions [ 51 , 52 ]. Moreover, the presence of immunosuppressive agents, including pollutants, within their habitats can impair the biological functions of these animals [ 53 ]. Also, the limited genetic diversity, the absence of advanced breeding techniques, and the challenges posed by genetic constraints, such as inbreeding depression in commercial shrimp populations, have hindered the development of superior shrimp strains with desirable traits [ 54 , 55 ].…”

Immunotoxicity of Xenobiotics in Fish: A Role for the Aryl Hydrocarbon Receptor (AhR)?

“…The complication with immunotoxicity is that a chemical effect on, e.g., cytokine transcription or phagocytosis activity, is not yet adverse per se; only if it propagates into a compromised defense capacity against pathogens or reduced health it becomes ecologically relevant [261]. Although in most cases we are not yet in a position to causally connect xenobiotic-induced AhR activation, altered immunity with reduced health and pathogen resistance of fish populations, the strong association between exposure of wild fish populations to xenobiotic AhR ligands, and elevated disease outbreaks and prevalence in those populations should attract increasing attention to the immunotoxic activities of environmental contaminants.…”