Timothy Parker will present a Graduate Exit Seminar at 2:00 p.m., Aug. 15, in 245 Kottman Hall. His presentation is The Effect of Hypoxia in Association with Ammonia on the Survival, Growth, Behavior, and Gill Structure of Fish.
Hypoxia is a common phenomenon in aquatic environment typically occurring during late summer or late winter. Hypoxic events can alter fish habitat usage and cause massive fish kills. With the intensity of hypoxic event increasing and water temperatures warming, it is important to understand how hypoxia affects life stages of fish typically not exposed to hypoxia, such as juvenile yellow perch. In some species, hypoxia has been shown to cause gill remodeling to improve breathing efficiency (e.g. Crucian carp). Furthermore, increases in ammonia concentrations have been shown to occur during hypoxia periods. Ammonia in its un-ionized form is highly toxic to fish and causes histopathological changes to the gills, which are very damaging and can limit breathing efficiency. The goal of this research was to examine how a combination of ammonia and hypoxia alters the gills, and influences ammonia toxicity in common carp. Additionally, the effects of hypoxia on growth, survival, and oxygen consumption of larval yellow perch were investigated.