the need to do it and do it right is urgent and ongoing and it hasn t been done yet. in this hour we continue to try to illuminate this critical element of the biggest story in the country. we had our first oil contact in the state of mississippi in mississippi sound and some islands to the west. louisiana s been impacted and the threat is shifting to mississippi and alabama. that s thad allen heading up the government response to the bp oil disaster, explaining what winds from the south and the west bring now. they bring this. oil on barrier islands, in alabama, and in mississippi. they also bring reports of an oil slick visible in the water, nine miles off the coast of florida and preparations to try to keep that oil from coming ashore in places like pensacola. that s all in addition to the 125 miles of louisiana coastline that s been hit by oil thus far. some of that is beach. sandy beach. but most of what s been hit by oil isn t beach. most of it looks like this. land
david talking about where new orleans started in terms of being on the natural levee. we think about the city obviously not physically moving towards shore towards the shore, but the shore encroaching in towards the city. how much of these wetlands have we been losing and why? that s the tragedy of the thing. we re losing 25 to 30 square miles of wetlands a year here, which basically during the time we re talking, maybe an area the size of a football field may have disappeared. where that s coming from is oil and gas extraction, which has seen the subsidence created. then of course the canals that have been driven into the well sites are causing erosion. so it s a combination erosion and subsidence is slowly eating these wetlands away. david, can you explain how it is that wetlands like, this both the swampy wetlands and the marsh, how they insulate places