 RAISING REDFISH -- STATE RELEASES HATCHERY-BORN RED DRUM TO SUPPLEMENT STOCKS Palm Beach Post -- Thursday, August 2, 2001 By: Willie Howard, Palm Beach Post Staff Writer PORT MANATEE -- In the fall, when water temperatures drop and the days become shorter, redfish all over Florida will begin spawning. It begins in the late afternoon, usually on days with 10 1/2 hours of daylight or less. Male redfish follow females around, making a drumming sound with special muscles rubbing against inflated air bladders. The males' bronze colors intensify during courtship. Just after dark, often during a full moon or new moon, the females shudder and release up to 1 million eggs each, which are fertilized by the males. Redfish eggs float for 20 to 30 hours before larval reds emerge carrying the yolk sac that sustains them for three days before they begin feeding on tiny zooplankton. The beginning of life for millions of Florida redfish is an intricate process that can occur every three to five days during the spawning season. But few survive long enough to reproduce themselves. Cold weather, red tide, sharp changes in salinity and predators kill most young redfish before they complete their first year. Natural hardships, along with a severe depletion of the state's redfish during the blackened redfish craze of the early 1980s, led to strict rules on the harvest of redfish and a state fish hatchery that grows redfish in captivity and releases them to supplement wild populations of the popular game fish. The Stock Enhancement Research Facility (SERF) at Port Manatee has raised and released about 2.8 million redfish since 1988 - about the same time the prohibition on the commercial sale of reds, a one-fish recreational bag limit and an 18- to 27-inch slot limit took effect to protect wild stocks. The regulations have since brought the state's redfish population back to healthy levels. Releasing hatchery reds into the wild boosts the redfish recovery, helps offset recreational fishing pressure and allows state biologists to learn more about the process of raising and releasing Florida game fish. Adding hatchery redfish to wild stocks tends to stabilize nature's peaks and valleys to provide a steady flow of fingerlings into bays and estuaries, said Ted Forsgren, executive director of CCA/Florida, the recreational fishing group that helps supports the hatchery with member donations and pressure on state legislators to provide money. The hatchery redfish are being released into Tampa Bay and tributaries such as the Alafia River. During the past 13 years, hatchery reds have been released into estuaries in Volusia and Collier counties, Sarasota Bay and Biscayne Bay. In 1999, the state released 5,542 hatchery reds into the Indian River Lagoon and the St. Lucie River in St. Lucie County. Nearly 10 percent of those St. Lucie County reds have been caught and reported to hatchery scientists through the Angler Tag Return Hotline - most of them from the Herman's Bay area where many of them were released. Redfish tend to stay in the same neighborhoods where they grow up, though they often migrate out of the estuaries to join spawning groups after they reach sexual maturity around age 4. Of course, not all redfish behave the same as others. One hatchery-raised redfish released in Biscayne Bay was caught by an angler near Eau Gallie in Brevard County, having traveled 220 miles. Such findings are among the gems discovered through the stock-enhancement research. Among the other key questions researchers are trying to answer is whether releasing hatchery fish into the wild increases the populations in the long run. At some point, the habitat only has enough food and shelter to sustain a finite number of fish, though nobody knows what that point is. Other lessons come from the growing process itself. Biologists at the Port Manatee hatchery found that cormorants ate redfish fingerlings growing in outdoor ponds when they reached 3 inches -- apparently just the right size for the birds. The solution: netting to cover the pond donated by the Tampa CCA chapter. One advantage of the hatchery is that redfish there can be fooled into breeding all year long. Scientists manipulate light and water temperature to induce spawning in breeding-room tanks. They put "QUIET! Fish Spawning" signs on the doors and let redfish magic occur. Hatchery managers choose breeding redfish from waters within 20 miles of the area where the fish are to be released and do DNA analysis to ensure genetic diversity, said Bill Halstead, research administrator at the Port Manatee hatchery. Some of the hatchery research is purely economic. It costs about 10 cents to raise a young redfish to 30 days old, 25 cents to 90 days and $1.10 to six months. Although larger fish are more expensive, they have a greater post-release survival rate. The Tampa Bay project is expected to generate some conclusions about which size of fish is most cost effective to grow and release. "The ultimate goal is to make the recreational fishing experience more enjoyable," Halstead said, adding that the state might try growing spotted seatrout for wild release in the future. "We believe we can maintain a healthier, more abundant population of these species than we already have." But Halstead noted that the state simply is trying to supplement wild stocks, not replace them. Without sea grass beds, good water quality and other habitat essentials, releasing hatchery-raised fish is pointless. "If the habitat isn't there, either our fish won't survive or some other species will be displaced," he said. What to do if you catch a tagged fish The state released 5,542 tagged, hatchery-raised redfish in the Indian River Lagoon in St. Lucie County in 1999 and continues to gather information on the status of those fish. If you catch a tagged fish, record the tag number, date, time, total length. (If the fish is released, leave the tag in the fish.) Call the Angler Tag Return Hotline at 1-800-367-4461 or e-mail the information to: tagreturn@fwc.state.fl.us. Don't forget to include your name, address and phone number. More information: Call the Stock Enhancement Research Facility at (941) 723-4505 or visit www.floridamarine.org (click on fisheries, then stock enhancement). Copyright (c) 2001, The Palm Beach Post |