Abstract

One of the greatest challenges in the long-term maintenance of animals in zoos and aquaria is providing good medical care. Factors that influence the level of care include individual species requirements, basic facility design, and progressive husbandry and veterinary care. Marine mammals vary drastically in weight from small cetaceans less than 100 kg to killer whales reaching 5000 kg. Basic medical care may require that these animals be handled multiple times per day during the course of therapy. Recognizing that medical intervention can benefit individuals and groups of animals, efforts have been made towards improved handling techniques.

A few aquaria utilized false bottom floors over the years but adoption of the technique was slow because of alternative approaches. For many institutions, typical restraint techniques have centered on removing the water from medical pools to intervene then replacement of the water column after the completion of therapy. Earlier versions of false bottom floors often utilized crank and pulley techniques with eventual mechanism corrosion and increased maintenance. Water removal techniques have a number of disadvantages including storage or loss of water, increased handling time on descent and ascent, poor response time in emergency situations, limited choices in water depth, increased personnel needs, and additional equipment needs such as a crane.

The systems utilized at SeaWorld Orlando are based on a process used since World War II. This patented system uses hydraulic pistons to implement weight displacement. One advantage of this system is that there is no electric contact with the water environment. High-pressure pumps may be required to lift animals such as killer whales but these can be located away from the poolside. Marine grade aluminum is used for some structural support and the decking is composed of FRP (fiberglassed reinforced plastic) including the floor supporting I-beams eliminating corrosion.

There are currently four systems in place with the first installed in the medical pool for beluga whales. Operating from city water pressure this system can lift up to 3000 kg of weight and has been invaluable clinically for medical procedures. The second system was developed for killer whales and can lift 27,000 kg. A third system for manatees eliminated the need to dispose of thousands of gallons of water with each treatment. In addition it decreased the handling time for injured animals from 40 min to 1 min. This not only shortened treatment times but also freed up personnel for other responsibilities. A fourth system with under the floor pistons is currently being used for dolphins at Discovery Cove.