Busch Gardens' gift of tilapia thrills fishery

Busch Gardens needs to pull more than 1,000 blue tilapia out of a lake to clean it.

Less than an hour north of the theme park, a nonprofit group dedicated to alleviating world hunger through sustainable fish farming is struggling to replenish about 2,000 blue tilapia killed by winter freezes.

Their paths converged last week.

Sometime in the next couple of weeks - as soon as it warms up enough for the tilapia to survive outside - Busch Gardens will send about 1,000 fish to Morning Star Fishermen in Dade City.

The nonprofit organization, formed in 1993 by Hans Geissler and his wife, Sigrid, teaches people from Central America sustainable methods of raising tilapia. They also learn how to set up a system that uses the fish waste to fertilize vegetables and other plants that filter the water in which the fish live.

"We're definitely excited about the partnership," said Phil Hillary, Busch Gardens' assistant curator of zoological operations. "We looked at this as a great opportunity to help him with his facility, and also it helps us out as well."

Busch Gardens also is moving koi from one of two lakes stocked with fish. The koi are a draw; guests like to feed them. The tilapia, however, provide little benefit other than eating algae off pond walls; they are getting big and number between 1,000 and 2,000.

A Busch Gardens staff member who lives in Dade City mentioned Morning Star Fishermen. When reports surfaced about the fish kills at Morning Star, the theme park arranged a meeting with Geissler last week.

All of the fish in Geissler's outdoor tanks - about half of the 4,000 fish he had - died after a January freeze dropped the water temperature below 40 degrees. The water must be at least 50 degrees for the tropical fish to survive, and Morning Star's tanks aren't heated. Until this winter, they did not need to be.

"I've never seen anything like this in Florida," Geissler said. "We need warm weather. ... If the water temperature goes down, they don't eat a lot."

Geissler was able to save most of the fish in his indoor tanks by pumping in well water, which is warmer, and setting up a solar heating system.

He's thinking about installing a geothermal heating system for the outdoor tanks.

The park expects to be sending as many tilapia as it can move, which is about 1,000, Hillary said. When the time comes, the fish will be loaded into a 300- to 400-gallon tank of water that's rigged with aerators. A protective stress coating will be added to the water to replace the natural one the fish are likely to lose in the move.

The tank will be loaded onto a flatbed trailer and driven to Dade City.

Busch Gardens staff members learned about large-scale fish moves from their counterparts at Sea World, Hillary said. Such moves aren't common, though: The last time the park had to move fish was five years ago, which was the last time the lake was cleaned.

Mostly, it ships more manageable numbers of fish - small enough to fit in boxes.

"This is the biggest shipment I've been involved with," Hillary said.