|07-10-2005 12:05 PM|
Hurricane Dennis - The Aftermath
Landfall for Hurricane Dennis is just hours away. Winds are sustained at 140+ (Sched.4) with heavy rain, predicted to hit somewhere around Pensacola Fla. at 2pm Eastern.
I have been researching past storms and there effect on Fresh and Saltwater marine species. Nearshore and Offshore areas seem to be most effected, but Inshore areas although less effected, still have there issues as well. Water Quality or the lack there of seems to be the biggest problem. Increases in Turbidity can last up to 30 days in some areas after the storm makes landfall.
Increased levels of Soils, Ammonias, Phosphates, and Organic Carbon are to blame. These can cause larger than normal Phytoplankton blooms (Algae) which add to the mix. Oils and Fuels spilled during the storm from Boats and storage facilitys can also be present in increased levels weeks after the storm has passed.
After Hurricane Andrew hit in '92, aprox. 180+ million Freswater Fish died in the Atchafalaya River Basin, Louisiana. This was attributed to a release of Hydrogen Sulfide from bottom sediments and decaying matter which caused a severe drop in Dissolved Oxygen levels in the water table. This kill included aprox 7mill. Crappie and 5Mill. Large Mouth Bass!
Costal Saltwaters saw aprox. 9 Million fish killed. This was also due to sediment in the water, as well as "Gas Bubble Disease" which is caused by an increase in preasure. Of these species were 1 Mill. Spoted Sea Trout and 1 Mill. Black and Red Drum.
In the past years Hurricane's Fran, Bonnie and more recently Floyd have caused large fish kills and "Dead Zones" in the Cape Hatteras, N. Carolina area of Pamilco Sound. The rains and subsequent flooding from these storms have caused sewage tainted waters to flow into the sound. These Freshwater "Plumes" contain high levels of Human and Animal wastes that sit on top of the Saltwater Estuaries robbing them of Oxygen and reducing Salinity.
Wind action can also have an effect on Ponds and Lakes, moving otherwise tranquil water surfaces dramaticaly to one side to one side, causing sediment and organic material to rise from the bottom. Lake and Pond "Bottom Water" is typicaly much lower in disolved Oxygen, and this also gets brought to the surface. this action is called a "Turnover" and can effect Freshwater Fish Species.
Eggs of Spawning Fresh and Saltwater Species can be effected as well by these same reductions in Oxygen levels, increases in Turbidity and high levels of Polution and extreme runoff levels. Back to back storms in the same area can have effects that can last for years, sometimes completly changing a system from what it was.
So batten down the hatches my little finned friends, here comes Dennis!
The last Hurricane "Dennis" to threaten the U.S?.......Aug. of '99