The role of high-energy periodic wind events on seagrasses has been chiefly anecdotal. Sites in Biscayne Bay, FL and the Laguna Madre, TX are compared for 4 study sites. Two sites in Laguna Madre were investigated for seagrass test plots, sediment cores, vegetative mapping and aerial photography over a 4-year period, with a large-scale seagrass restoration (14.7 acres at one site and 60 acres at the second site) carried out in 1999. Hurricane Bret hit the 60-acre site two weeks after monitoring. A post-hurricane monitoring occurred. Aerial photos were subjected to analysis, available from 1996, 1998, 1999 post-hurricane and 2000. A second 14.7 acre Laguna Madre site was hit by a tornado after one half was restored in March 1999. Two lines of craters occurred which we documented by markers. The Biscayne Bay sites (in the Central Bay) had been mapped and ground truth data taken with sediment samples over years prior to a January 1983 hurricane force wind (off the south end of Key Biscayne). Morphological changes to the existing vegetation and corals were recorded. The second site (3 miles away) had been by examining aerial photos over a period of 20 years was restored with the seagrass Halodule wrightii during the summer, 1982, with 68% survival pre-gale in Fall 1981. Post-gale monitoring of seagrass beds showed the almost hurricane force wind caused substantial damage to the restoring seagrasses. Results of the four sites and comparisons of the vegetative cover, sediment and background vegetation will be discussed with data. Conclusions: 1.) Tornados can disrupt seagrasses leaving effects on for years; 2.) Gale force winter winds and hurricanes can alter shallow seagrass beds; 3.) Recuperation and re-growth after storm events can vary as to species and dissemule availability.

Key words: Biscayne Bay FL, hurricane, Laguna Madre TX, seagrass, sediment, tornados