I've been doing a bit of online reading about the long term effect of devastating hurricanes on coastal ecosystems. Here are two very interesting articles I've dug up.
Interestingly and very surprisingly, hurricanes generally have little long term effects on coastal ecosystems. Most marine and land animals successfully flee the area before the storm's arrival. The majority of lost animal life is caused by the loss of habitat (eroded mangrove swamps and smashed coral reefs) brought on by the hurricane. In undeveloped areas, the storm surge pushes salt water deep inland while wind driven waves and rain cause massive erosion. Inland vegetation that is not swept away is killed by inundation in brackish water. Very soon after the storm clears, the storm waters drain away and evaporate. Rainfall helps wash away residual salt. Within a few years, the previously inundated areas are recolonized by native plants and again support animal life. Smashed coral reefs remain alive, and regrowth is accompanied by recolonization by fish and inverts.
Some ecologists believe that hurricanes may have a beneficial effect on local ecosystems by flushing out shallow bays and scouring away dead vegetation and coral. I guess this is comparable to the sometimes beneficial effects of forest fires.
Most of the detrimental long term effects of hurricanes are attributed to chemical contamination from destroyed human industries (oil, chemicals, fertilizers). Certain structures (seawalls, levees, inland walls) can hinder the ecosystem's recovery by trapping storm water and preventing rainfall from washing away the salt. Heavy coastal development, dredging, and canal building thins the coastal mangrove buffer that protects the more vulnerable inland areas.
Hopefully the Gulf Coast ecosystems bounce back from Katrina the way the Carolina Cosat bounced back from Fran, Dennis, Floyd, and Irene. http://www.brightsurf.com/news/june_...ews_061604.php