Florida's strength as a magnet for retirees seeking sun, sand and palm trees may be diminishing.

A recent University of Florida study of U.S. Census data shows the numbers of elderly people moving to the Southeast dropped in the first half of the 1980s compared with the 25 previous years.Stephen Golant, a university demographer who published the study in July's Journal of Gerontology, predicts the drop will continue through the 1990s for several reasons:

- Fewer babies were born during the Depression, the age group now beginning to turn 65.

- The Northeast and Midwest provide more retirement opportunities.

- The recession in the early '80s made it difficult for Northern retirees to sell homes and move.

Also, Golant said, a youth movement seems to be stirring in Florida, with a backlash against retirement communities.

"What's happening is that the glamour of having an older population in one's community is, if anything, dampening rather than increasing."

Communities once synonymous with retirement - Miami Beach and St. Petersburg - have made efforts to attract younger people because retirees demand more services, he said.

Florida population projections show the state's over-65 population growing 26 percent in the 1990s, compared with 71 percent in the 1970s and 44 percent during the 1980s.