- Six months after Katrina, the mark left on the natural world by last year's blockbuster hurricane season is a complex mix of more fish and shrimp, less habitat for them to live and breed in, and millions of gallons of oil possibly lost forever in south Louisiana's marshes.
- In terms of habitat, however, the storms sharply accelerated a coastal erosion problem already responsible for a decades-long decline in seafood production. And a lasting stain was left by at least nine major oil spills and countless hazardous-material containers strewn from Mississippi to Texas.
- Meanwhile, federal and state biologists report stocks of shrimp, fish and crabs are at their highest levels in years: a phenomenon attributed to a combination of lighter fishing pressure and a jolt of nutrients stirred up by the storms that served to stimulate the food chain.
Six months after Katrina, the mark left on the natural world by last year's blockbuster hurricane season is a complex mix of more fish and shrimp, less habitat for them to live and breed in, and millions of gallons of oil possibly lost forever in south Louisiana's marshes.
The central Gulf Coast was spared the massive fish kills that followed Hurricane Andrew in 1992. While some die-offs occurred, evidence has emerged of a spike in the populations of several saltwater species -- perhaps a result of the region's shattered fishing fleet.
In terms of habitat, however, the storms sharply accelerated a coastal erosion problem already responsible for a decades-long decline in seafood production. And a lasting stain was left by at least nine major oil spills and countless hazardous-material containers strewn from Mississippi to Texas.
Just as significant, however, is what the storms did not do. Federal scientists say the 224 billion gallons of foul floodwaters pumped out of New Orleans after the storms quickly dissipated in Lake Pontchartrain and the Gulf of Mexico.
Researchers from the Battelle Seattle Research Center in Seattle, who attempted to mimic the floodwater's movement through computer simulations, have suggested much of the pumped-out water may be trapped in Lake Borgne. But extensive analyses of potential contaminants in seafood by state and federal fisheries scientists have turned up only trace amounts of chemicals such as PCBs and petroleum.
That contrasts sharply with news reports that continue to depict a grimmer situation. As recently as December, an article appearing in the Orlando Sentinel described the pumped-out floodwaters as a "slug of germs and chemicals . . . floating toward Florida's coast, drifting out to the Atlantic or lurking somewhere in between."
"By and large, the facts don't necessarily follow a lot of the speculation that was out there early, in terms of the chemicals that were out there and the threat to human health," said Steven Murawski, a senior scientist at the National Marine Fisheries Service, which has conducted nine rounds of seafood sampling from Texas to Florida.
Meanwhile, federal and state biologists report stocks of shrimp, fish and crabs are at their highest levels in years: a phenomenon attributed to a combination of lighter fishing pressure and a jolt of nutrients stirred up by the storms that served to stimulate the food chain.
Louisiana's inland waterways still are recovering from localized fish kills, but the scope of that damage is considered far narrower than the estimated 184 million fish that died in the Atchafalaya Basin during Hurricane Andrew.
Excess oxygen caused by heavy loads of organic material entering rivers after flooding caused fish kills along the Blind, Amite and Tchefuncte rivers after Katrina. Toward the coast, additional fish kills caused by an influx of saltwater were reported near Venice and Caernarvon in the southeast corner of the state, in the Atchafalaya Basin in south-central Louisiana and in Grand Lake and White Lake in the southwest, said John Roussel, assistant secretary for the Wildlife and Fisheries Department.
Plans are being made to restock the waterways with bass, catfish, bream and other species. For Grand and White lakes, however, Roussel said salinity levels -- the amount of salt in the water -- are still too high, keeping fish from returning and also threatening to kill off aquatic plants.
The direst story emerges from the physical toll the storm took on Louisiana's wetlands. Louisiana's coastal marshes comprise about 80 percent of the Gulf's wetlands, estuary systems that are vital for reproduction of shrimp, redfish, speckled trout, blue crabs, bluefish, menhaden and many other recreationally and commercially important species. The wetlands also serve as a natural buffer against hurricanes.
Rita and Katrina washed away or flooded about 118 square miles of wetlands, or about 75,500 acres.
Beyond those losses, oil spills caused by Katrina totaled 8 million gallons across southeast Louisiana, according to the Coast Guard. The most publicized spill, about 1 million gallons at the Murphy Oil refinery in St. Bernard Parish, occurred in a residential area. The rest were concentrated in rural areas or along the Mississippi River.
More than 2.3 million gallons of spilled oil have not been recovered.
As for other hazardous substances displaced by the storms, the U.S. Environmental Protection Agency has collected almost 4,200 tons of materials in 2.2 million hazardous material containers, from gasoline cans to drums of highly toxic industrial chemicals. That includes 675,000 containers from the coastal parishes of St. Bernard, Plaquemines, Lafourche and Vermilion and from Grand Isle in Jefferson Parish.
But many containers, as well as fishing boats and vehicles laden with fuel, were likely lost in marshes or water bottoms, state and federal officials have said. And in western Louisiana, about 1,400 hazardous-materials containers with up to 350,000 gallons of liquids and gases remain out of the EPA's reach.
The containers were found in the federally operated Sabine National Wildlife Refuge. Under the Stafford Act, which is driving the federal response to the recovery, that makes them off-limits to retrieval by agencies under the direction of the Federal Emergency Management Agency. FEMA emergency money can be spent only on state and local needs, according to EPA spokeswoman Cynthia Fanning.
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Matthew Brown can be reached at email@example.com or (504) 826-3784.