Abstract

During 2008/2011, we received 5 Ladoga ringed seal (Phoca hispida ladogensis) pups: 2 females and 3 males. Four animals were in a state of extreme exhaustion with a loss of more than 40–50% of their weight. These pups' weight ranged from 4.5 to 10 kg. One animal had normal weight, but died from its closed head injury before it could be helped.

When assistance was rendered, the primary imperative was the animal's dehydration and recovery of electrolyte balance. For that, Rehydron solution was injected at 10–15% of the body weight, and on the first day this procedure was repeated every 3 to 4 hours. For feeding ringed seal juveniles, we used a soft plastic tube, 10 mm in diameter. Subsequently, we fed the animals with a mixture of minced fish, fish oil and water and gradually the pups were transferred to a whole fish diet. One liter of the mixture contained 600 ml of water, or Rehydron, and 400g of minced herring of the Atlantic (Clupea harengus harengus). The caloric value of 1 ml of mixture was 1 kcal/ml. Before feeding, the mixture was heated in a container placed in water warmed to 20–25°C. Starting from the second day of maintenance, before every feeding with the mixture, the seals were offered freshly-defrosted fish. If the seal showed no interest in the offered fish for several days, or did not consume the necessary amount of the mixture of 15–20% of its body weight, forced feeding was started. The ringed seals were fed on the Baltic herring (Clupea harengus membras). The transition from the mixture to whole fish occurred gradually over 2–3 days, and the amount of the mixture gradually decreased as the amount of solid fish increased. The number of feedings per day decreased from 5–6 feedings down to 4 feedings at four hour intervals. Eventually, the seal was offered fish in the water in which it was swimming to see if it would feed independently. After the appearance of sufficient interest in food, the seal was transferred into a water enclosure where it started feeding independently on fish it had to catch by itself so as to develop the natural feeding instincts that would be necessary when it was released. As the rehabilitation progressed, the fish was thrown into the water from under a screen so that the animal did not associate the presence of a human with the appearance of the food. A vitamin-mineral complex "SEA TABS® for Larger Marine Animals (Cetaceans, Pinnipeds, etc.) was used every day. Within three to four days, after the seals were received the animals were administered (Prazikvantel and Panacur) for dehelmintization. The daily increase in weight experienced by these animals during rehabilitation was from 0.13 to 0.20 kg; the average duration of rehabilitation of Ladoga ringed seal pups was 2 months. When the animals reached a body weight of 17–20 kg, they were released. Before release, the seals were marked with acrylic paint.

* Presenting author