Katrinas effect on aquatic ecosystem?

[MattAquaBio]

My girlfriend and I watched something about Hurricane Katrina today and it got me to thinking about the damage the hurricane did to the aquatic ecosystem (yes i know its small beans in comparison to the human toll, but i was curious nevertheless). It talked extensively about the storm surge and how devestating it was.
So i was thinking. If there is a freshwater pond in a New Orleans neighborhood and the storm surge floods it just like it did the rest of the city what would it do to the wildlife? The freshwater would become Brackish at the very least correct? Would it kill all the fish in the pond? If the fish could adapt to the salt even temporarily, wouldnt the SUDDEN change from fresh to salt kill them anyway? Even if they DID survive the mixing of the salt and freshwater, what happens when the water becomes stagnant and polluted? All the chemicals and oil and waste getting thrown in the water from the surge, wouldnt it turn the water toxic to them? What happens when the water has receded and the pond is a pond again. Wouldnt it remain salt/brackish anyway?
Is it possible that critters hitching a ride on the surge could make the "salt/brackish" pond their home? Assuming that is, that any of the fish survived the surge and pollution.
Whenever the surge moved back out and took all the stagnant polluted water back out, was that damaging?

 

[majolo]

There was an article in a recent Tropical Fish Hobbyist about pipefish. Part of the article talked about collecting trips in Louisiana before and after Katrina. You might find it interesting if you can look it up. I don't know which month it is in.

 

[fishfreek]

On the grounds of the pond fish if the sudden change in salinity and temperature did not kill the fish the leaching of sewage and other contaminants like under ground gas tanks, etc would polute the water till it killed them.

 

[An t-iasg]

I just found this article on the Fox News page:

http://www.foxnews.com/story/0,2933,210834,00.html

 

[QTOFFER]

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.
http://ncseonline.org/nle/crsreports/05nov/RL33117.pdf#search="hurricane ECOSYSTEM"
http://limnology.wisc.edu/courses/zoo725/GulfCoast_manuscript.pdf#search="hurricane ECOSYSTEM"

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_04/EDU_news_061604.php