Bay Daily readers will recall last week’s report of the algal blooms that created “mahogany tides” in the lower Chesapeake Bay and Hampton Roads during the first few weeks of August.
The algal blooms – explosive growths of algae spawned by hot weather and excessive nutrient pollution flowing into the Bay from a variety of sources -- turned waters a dark brown, smelly mess in Hampton Roads creeks and rivers. Dramatic aerial photographs documented the troubling extent of these blooms.
Also documenting the blooms and their insidious effects on the waters of the Bay were the National Oceanic and Atmospheric Administration (NOAA)’s Chesapeake Bay Interpretive Buoy System, often nicknamed the Bay’s “smart buoys.” That’s because they’re jam-packed with gizmos constantly checking water, wave, wind, and weather conditions. The buoys then beam the data to computers that anyone anywhere in the world can access online. You can even call the buoys by telephone and “talk” to them to get real time data and conditions.
Fluctuations in the amount of chlorophyll in the Bay and its tidal rivers are natural, especially from day to night. But you can readily see that between about August 6 and 14, there were huge spikes in the amount of chlorophyll -- algae -– in the Elizabeth River. That is precisely when the “mahogany tides” were sweeping through Hampton Roads.
Now take a look at this graph showing levels of dissolved oxygen in the water during the same time period. You can see the large spikes in dissolved oxygen during the mahogany tides when all that algae were doing their thing – photosynthesizing and producing oxygen. You can also see the natural fluctuations from daytime to nighttime.
But see what happened to dissolved oxygen in the surface water near the smart buoy starting about Aug. 15. That’s a day or two after the mahogany tide algae died off and began decomposing, a process that naturally uses up oxygen in the water. That’s why the oxygen plummets for several days to around 2-3 milligrams per liter, amounts that barely allow oysters and crabs to survive and too low for shad, perch, and striped bass. So on those days, if you were a Bay critter, you either swam away from the area, held your breath (as clams and oysters can for awhile), or you suffocated.
That is why it is so important we reduce the massive amounts of nitrogen and phosphorus now polluting the Bay. It creates a deadly chain reaction. The pollution over-fertilizes Bay algae, which explode into blooms like the mahogany tides, which die and decompose, which suck oxygen out of the water, which stresses or kills the life in the Bay. Unfortunately, such blooms are becoming regular summertime visitors to the Chesapeake Bay, almost as predictable as jellyfish.
That’s the bad news. The good news is, we can fix this, and Virginia and the other Bay states have a golden opportunity to do so right now. Bay state officials are working with the federal EPA to create a pollution “diet” for the Bay that calls on everyone -- localities, farmers, developers, homeowners – to reduce pollution to levels that are safe for the Bay. The diet and the plans to stick to it will soon be public, and EPA and the states will be asking for public comment.
Take a minute to demand that Virginia produce a fair but aggressive plan that holds all polluters accountable and responsible. You can also encourage Virginia’s elected officials, especially Senators Mark Warner and Jim Webb, to support the Chesapeake Clean Water Act now in Congress. This strong bill will provide critical federal funding and accountability for Bay restoration efforts.
You can really help restore the Bay…and make mahogany tides an infrequent visitor to Virginia.
By Chuck Epes
Take a minute to demand that Virginia produce a fair but aggressive plan that holds all polluters accountable and responsible.
Posted by: oxygen monitor | 03/29/2012 at 05:28 PM
It creates a deadly chain reaction.
Posted by: marlon | 04/16/2012 at 07:45 AM