Immunosuppression Cascade in the Florida Manatee (<I>Trichechus manatus latirostris</I>)

Abstract

The Florida manatee (Trichechus manatus latirostris) is a federally endangered marine mammal that resides on both coasts of the Florida peninsula. The species faces many anthropogenic and natural threats, including boat strikes, exposure to harmful algal blooms, and cold water temperatures. We have developed a conceptual model that depicts how changes in the environment, such as reduced water temperature, can trigger an immunosuppressive cascade of interrelated diseases and pathological conditions ultimately leading to the death of the animal. Although the Florida manatee has a relatively robust immune system, rendering it resistant to several diseases, the onset of unfavorable environmental conditions has been shown to compromise the immune system, often leading to infections that make an animal more susceptible to opportunistic pathogens. In this paper, we review several common diseases of the Florida manatee and compare and contrast their symptoms. We then interrelate these diseases and generate a conceptual model of a cascade of immunosuppressive conditions originally triggered by adverse environmental conditions or one of the diseases. The end result of the cascade is the death of the animal.