Abstract

Birds that live full-time or part-time in a marine environment have developed specialized mechanisms to cope with their saline surroundings. Short-term and long-term physiologic changes, along with evolutionary adaptations in the gut, salt glands, and kidneys are necessary to survive in a marine environment. Therefore, housing pelagic birds on freshwater for the extended periods required for rehabilitation could cause physiological stress. These housing and fluid therapy constraints can impact the electrolyte levels and hydration status of aquatic birds. In October 2009, a harmful algal bloom of the algal species Akashiwo sanguinea along the Oregon Coast caused mass seabird beaching due to inadequate waterproofing. Some of the seabirds stranding in this event were sent to the San Francisco Bay Oiled Wildlife Care and Education Center. Twenty-three Common Murres (Uria aalge) admitted during this event in November of 2009 were enrolled in a prospective study. These birds were gavaged with freshwater and housed on freshwater throughout the rehabilitation process. As part of their pre-release exam, we performed serum chemistries including measuring electrolyte levels. We found significantly lower sodium and chloride levels when compared to a wild population. Our study suggests that the use of freshwater for fluid therapy and housing of pelagic birds could cause physiological stress and decrease the likelihood of a positive outcome.