A Fierce Storm

In mid-August 1992, television and radio audiences were alerted to a potentially damaging hurricane that had formed in the Atlantic Ocean. Satellite imagery showed a large swirling mass of clouds rotating around an area of low pressure and heading toward the continental United States.

On August 24, this hurricane struck the eastern coast of Florida, passed over the Florida peninsula, entered the Gulf of Mexico, and moved northwesterly until it slammed into the Louisiana coast on August 26. Hurricane Andrew, as it was named by the National Weather Service, caused over $27 billion worth of damage in Florida and Louisiana. It was not only the costliest storm to strike the U.S. mainland but it was also one of the most intense. (Figure 1)

Hurricane Andrew, with winds of 200 kilometers per hour (124 miles per hour), destroyed urban and other settled areas in Louisiana. It also swept across a variety of economically important natural ecosystems in south Louisiana, including barrier islands, coastal wetlands, and forested wetlands. A closer look at the life span of this storm shows that its path of destruction was inevitable.

On August 14, satellite photography first indicated a strong tropical wave off the west coast of Africa. This weather pattern achieved tropical storm strength on August 17 and, by August 22, its winds had further strengthened to hurricane force--120 kmph (74 mph). The storm rapidly intensified and by August 23 had become a Category III hurricane (see "How Hurricanes Form,") with winds of 193 kmph (120 mph). The next day, August 24, it struck the eastern coast of Florida and passed over the Florida peninsula in only six hours.

As an even stronger hurricane with winds of 225 kmph (140 mph-a Category IV storm), Hurricane Andrew moved northwesterly across the Gulf of Mexico. As people all along the Gulf of Mexico tried to predict its course, the hurricane's second landfall was along Louisiana's coast August 26.

It first passed near the barrier islands along the central gulf coast of the state with 225-kmph (140-mph) winds and a storm surge of 2 m (7 ft). A combination of these winds and the resulting strong waves and storm surge eroded 30-40 percent of Raccoon Island as well as the western arm of Whiskey Island. This erosion reduced the significant protection that those barrier islands could offer to coastal marshes and swamps from future storms.

Hurricane Andrew then moved across the water between the islands and the Louisiana mainland and struck coastal marshes near Cypremort Point. Large sections of marsh in western Terrebonne Parish received extensive physical damage.

Still very strong, the hurricane traveled through the swamps and forests of the Atchafalaya Basin. Aerial reconnaissance shortly after the storm revealed large tracts of downed and mangled forests. More than 40 percent of the bottomland hardwood forests in Iberia, St. Martin, and St. Mary parishes were severely damaged. By the time the storm neared Baton Rouge, its peak wind gusts were still near hurricane force, 113 kmph (70 mph).

About 24 hours after Hurricane Andrew struck Louisiana, it took a northeasterly track and was finally downgraded to a tropical depression. On August 28, it merged with an advancing cold front and died in Pennsylvania.

In just two weeks the hurricane created damages of $27.2 billion and affected the incomes of many Florida and Louisiana residents for years. Hurricane Andrew passed over a densely populated area in south Florida, which accounted for the bulk of the monetary losses and loss of lives. Its landfall in Louisiana was in a sparsely settled area, but storm damages in the state still reached $2.5 billion. The fishery and aquaculture industries suffered enormous losses. Although memories of the storm are now fading, its impact can still be seen and will be felt for years to come.

Storms such as Hurricane Andrew are significant forces in the evolution of coastal systems, helping alter the shapes of barrier islands, coastal marshes, and swamps and other wetland forests. Because scientists, fishermen, and foresters alike have become increasingly aware of the values of these systems, interest in understanding, protecting, and restoring them has been increasing as well. Recent passages of federal laws such as the Coastal Wetlands Planning, Protection, and Restoration Act of 1990 indicate that, among lawmakers and the people they represent, there is a growing appreciation of systems that hurricanes affect.

Three months after Hurricane Andrew, the U.S. Congress provided funds so that damages to Louisiana's coastal resources could be assessed and monitored. Headed by the National Biological Service's Southern Science Center, 23 studies of the ecological impacts of Hurricane Andrew were planned and completed. These studies examined the short- and long-term effects on coastal barrier islands, wetlands, and swamps and bottomland hardwood forests in Louisiana and their wildlife. (Figure 2)

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