Special Report: Awaiting the Havoc from Hurricane Isaac

_Editor's note:
Go here for a video about the hunting and fishing opportunities at risk in the Mississippi Delta.

For an interview with Ryan Lambert, who owns a fishing lodge where Hurricane Isaac is projected to make landfall, go here._

Like all hurricanes these days, Isaac is bad news for Louisiana's coastal fish and wildlife.

Hurricanes are to the great estuary of the Mississippi River what fire is to western forests: A natural, needed force in a healthy ecosystem, creating openings for renewal of key species and leaving behind a surge of life in the wake of its destructive force.

Unfortunately, Louisiana's southeastern coast - the Mississippi delta - is not a healthy ecosystem. In fact, it is sick and dying and unable to recover from wounds that any type of tropical storm can deliver - even Category 1 Hurricane Isaac.

As the storm moved ashore Tuesday, Louisiana sportsmen feared these consequences:

• Marsh erosion - still averaging 16 square miles a year due to levees and canal dredging - will take a sudden jump from the pounding of wind-driven waves over a 24- to 48-hour period.

This is the most serious impact, because these marshes are the engine that drives the greatest fisheries production in the lower 48 states and provides winter homes and resting stops for 75 percent of the continent's migratory waterfowl. When the river was still unchained by levees it could quickly rebuild any losses from storms. Now, starved of sediment, each square mile of loss is another nail in its coffin.

* Loss of wintering habitat for waterfowl.

The storm surge now washing over these marshes will wipe out the summer's growth of submerged aquatic vegetation (SAVs), which provide the energy migratory waterfowl need to not only survive the winter, but to head home healthy enough for the energy-intensive reproduction cycle. In a healthy, growing delta, the birds could simply move to different locations to find food, and the current of fresh water and nutrients washing over the scoured splays would quickly begin growing a new crop. But the deteriorating condition of these marshes makes regeneration difficult before winter comes.

* Resurfacing of BP oil pollution.

As oil moved ashore in 2010, much of it absorbed sand and silt in the turbid coastal waters, gradually morphing into tar balls and mats that sank to the soft bottom of the marshes. Much of this sticky mess was quickly covered by more silt and sand with the action of waves and tides-- and the rapid subsidence the entire delta is experiencing. Since then, every stiff southerly blow that carried large waves has uncovered many of these sunken mats, which still contain toxic polycyclic aromatic hydrocarbons (PAHs) that are highly toxic to fish wildlife and humans.

Of course, nature never takes without giving. If the system remains true to the projected path, after dealing these serious blows to fish and wildlife in south Louisiana, it could bring relief and health to the drought-scorched central and upper sections of the Mississippi River valley.

Stay tuned for a post-storm report.