Tracking conditions from home computer


Technology: An expanding DNR Web site will soon provide up-to-the-minute water-quality readings for nearly every corner of the Chesapeake.

September 20, 2002|By Tom Horton | Tom Horton,SUN STAFF

WANT TO KNOW how the Chesapeake Bay's doing? It used to take a long answer because the bay's a big place.

But soon, you might just be asked in return what river or creek is nearest you, and told to bring it up on a Maryland Department of Natural Resources (DNR) Web site.

There you would find information on how clear the water is, how much oxygen's in it, how salty it is, whether conditions are prime for a fish kill or algae outbreak, and how conditions are for underwater grasses.

Better yet, the information will be "real-time," based on measurements every 15 minutes; and you'll be able to see everything that's been going on within the last several hours.

Only the fish will have a better picture.

It's not far-fetched to see these fast-emerging monitoring capabilities creating something the media can use for water-quality measurement akin to the "code red" alerts broadcast during air-pollution episodes.

Imagine the nightly broadcast: "And early this morning that big algae bloom on the Magothy River crashed and began decomposing. Goodbye to any oxygen in the water there. If you've got waterfront, expect fish belly up and rotting by the thousands!"

That's only a little fanciful. You can get on the Web right now and get such information for the Severn and Magothy rivers, as well as Maryland's seaside bays and Tangier Sound (see directions below).

Recently, I got Rob Magnien, a scientist with the Maryland DNR, to demonstrate the new monitoring for Ben Oaks on the Severn about seven miles upstream from Annapolis.

The living is good at Ben Oaks, where shaded lawns slope to boat slips along the water. Kids splash in a community swimming cove, and families picnic along little islands and small, sandy beaches.

But the living has been harder for yellow perch, for which the upper Severn used to be famous. A tasty little denizen of the bay's fresh and brackish tributaries, yellow perch are among the earliest fish to mass for spawning each spring, giving anglers their first break from winter.

Despite a 14-year fishing closure around Ben Oaks, yellow perch are surviving there no better than in bay areas where they are heavily fished, says DNR biologist Harley Speir.

There was no obvious reason for the high fish mortality around Ben Oaks, Speir says. No industrial discharge, no sewage plant overflows.

Biologists suspected the smoking gun was "low d.o.," or dissolved oxygen - blamed on algae blooms that erupt, boosted by nutrients from septic tanks and runoff from lawns and pavements. When the bloom finally dies back and decomposes, it can suck all the oxygen out of the water.

Such d.o. "crashes" can kill fish and their eggs and larvae, but they can come and go in hours or a few days, and often go undetected.

This is where Magnien's group comes in. They have placed permanent, high-tech probes in the water at Ben Oaks and other spots. These give continuous readings of algae, dissolved oxygen and other water-quality indicators. A cellular link on the probe transmits the data to DNR's computer daily.

A related monitoring technique that can cover hundreds of miles in a few days is being developed in conjunction with the University of Maryland's Chesapeake Biological Laboratory. Small boats, outfitted with probes and computers, cruise at speeds to 25 knots, taking thousands of water-quality readings daily across the bay's near-surface waters. An onboard Global Positioning System logs where each sample was recorded.

Magnien says all of this, part of a pilot program, "has really opened our eyes to what is happening in the shallow waters of the bay with dissolved oxygen."

Bay managers traditionally focused on the far larger areas of low oxygen in the bay's deep channels. These are a problem, Magnien says, but don't tell much about what's harming the abundant aquatic life of the bay's shallow edges and little headwater creeks.

Indeed, charts of reported fish kills around the bay in recent years show most occur in the shallow, upper creeks like those around Ben Oaks.

Such widespread and continuous monitoring will be crucial to meeting a new generation of bay water pollution standards being written.

These standards will vary from river to river, and from shallow water to deep, requiring a new level of monitoring to determine whether areas of the bay are meeting them or not.

It's also likely to make us more aware of how pleasant living at the bay's edges can sometimes come at nature's expense.

(Check it out: Click on New Monitoring Technologies, then Continuous Monitoring, then Current Results, then to bottom of page to choose the location you want.

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