Impacts of Contaminants on Crustaceans in the Field

Abstract As with many groups of wildlife, crustaceans have seen considerable declines in their populations over the past century due to fisheries, habitat destruction, climate change, species invasions, and poor water quality. Many inorganic and organic pollutants can compromise the physiological performance of crustaceans, and it is yet unknown to what extent man-made chemicals can act as endocrine disruptors or interfere with chemical communication. Field monitoring programs have revealed examples of developmental abnormalities, including fluctuating asymmetry, limb development, intersexuality, and embryo aberrations. Ingested plastic debris may clog digestive organs, and entanglement in marine debris items often leads to severe injury or suffocation. Pathogens and disease are major sources of mortality in crustaceans both in the field and in aquaculture, and their impact is only just being realized. Some contaminants bioaccumulate in tissues, causing long-term intoxication whereas other contaminants are released in massive pulse events, such as oil spills, resulting in acute catastrophic effects. This chapter briefly summarizes the use of crustaceans in ecotoxicology and as bioindicators. We review the toxic effects of acute and chronic pollution and how it may negatively affect crustacean populations in the field. Based on notable declines of crustacean species over the last decades, either periodically or persistently, we assemble a body of evidence for the possible contribution of contaminants to this decline. Special attention is given to microplastics and developmental abnormalities, as well as diseases and parasites. We close this chapter with regards to open questions that should receive further attention for future research.