Mystic Marinelife Aquarium (MMA) recovers and treats marine mammals stranded along the Connecticut and Rhode Island shoreline. Seals comprise the majority of the animals handled and are found ashore for a variety of medical, environmental or behavioral reasons. Our goal in working with a stranded animal is to identify and treat any problems and to return the animal to a condition which allows it to provide for itself in the wild. Institutional goals must also be met; these are based on concerns regarding zoonotic and potentially epizootic diseases, as well as available space and manpower to provide quality medical and husbandry care. Variables such as age, body condition of the animal and the length of time stranded, may result in secondary problems which complicate successful rehabilitation and release. One such secondary problem is the ingestion of foreign bodies, especially those that cannot pass through the lower digestive tract.

A juvenile male harp seal (Phoca groenlandica) was found stranded at Point Judith, RI and arrived at MMA on February 26, 1995. The animal was thin (weight=21 kg) and appeared depressed and stuporous. Elevations were noted in the packed cell volume (56), total protein (7.0 g/dl), serum urea nitrogen (149 mg/dl), creatinine (1.5 mg/dl), lactic dehydrogenase (883 u/L), and creatine phosphokinase (950 mg/dl). The calculated serum osmolality was 479 mOsmol/kg: hypernatremia (207 mEq/L), hyperchloremia (151 mEq/L) and hyperkalemia (5.0 mEq/L) were resolved over a three-day period through isotonic fluids administered via the extradural venous sinus. The initial complete blood count indicated a leukocytosis (WBC=17.1) with a monocytosis (29%, 4959 absolute), which resolved within 48 hours (WBC=13.1; monocytes 11%, 1441 absolute). Multiple, 1-4 mm white, plaque-like lesions which bled easily and resembled infection by Fusarium sp. were noted along the hind flipper and perineal region.

Foreign bodies were palpable in the stomach and a smooth, rounded 1 cm stone was passed in the feces the following day. Radiographic examination revealed the presence of multiple discrete radiopaque masses in the stomach, ranging from 1 to 6.5cm in length. Treatment with a bulk laxative (Fibercon-DR, Lederle Lab., Pearl River, NY) resulted in the passage of a small amount of sand within 72-hours. Despite a willingness to take food on its own, the animal continued to regurgitate fish shortly after feedings and seven days after arriving at MMA, its weight had dropped to I 9 kg. In view of its deteriorating condition and questionable ability to successfully maintain itself in the wild, the animal was euthanized. Upon necropsy, 13 rocks of variable size, weighing 1108 g, were found nearly filling the stomach. Multiple ulcerations of the gastric mucosa were present, ranging in size from 2 mm up to 5 cm; gross abnormalities were not detected in any other organ systems.

Ingestion of rocks has been noted incidentally in a number of pinniped species.

Young phocids may have a predilection for this behavior, given the abruptness of weaning in this group, and the urgency of their need to establish successful foraging strategies before losing maternally-derived blubber stores. Mortality during the first year may approach 40% and much of this is due to starvation and associated conditions. There may be a survival advantage to ice-bred phocids which ingest ice or snow prior to establishing successful foraging strategies. Stranding at an early age in areas without a readily available source of ice or snow may result in increased opportunities to ingest foreign objects. This case, along with anecdotal reports from other regional stranding centers, highlights a condition that may comprise the successful rehabilitation of young, stranded seals.