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Chesapeake Bay News

Archives: July 2009

Jul
16
2009

Looking for fish habitat on the Magothy with a 4-year-old

On Friday, July 3, I did my usual twice-monthly volunteer water quality sampling at four sites on the Magothy River near where I live. I started doing this in 1991 through a program run by Anne Arundel County to get a better understanding of Bay water quality, and I’ve kept doing it ever since. The county program was discontinued, but I’ve continued sampling with the Magothy River Association, which has other volunteers who also do water monitoring. 

This monitoring trip was different from recent ones because my four-year-old granddaughter came with me. This was only the second time she'd seen any part of the Chesapeake up close (she lives in Vermont and usually visits us at Christmas).  Thus, I was thinking about how she was reacting to it.  It’s been a long time since my own kids helped me with monitoring (my youngest child is 26).

We started our sampling at the end of the Bayberry pier, on the south shore on the lower part of the river’s mainstem, where all seemed to be well. Several people were catching juvenile spot (Leiostomus xanthurus) pretty regularly, and my granddaughter was fascinated by watching them. The reason they were able to catch these bottom-dwelling fish at that location was apparent when we measured the dissolved oxygen (DO): it was over 8 mg/l on both the surface and bottom, plenty of oxygen for fish.  The bottom DO here has not fallen below 5 mg/l (the EPA and state standard for fish habitat) since I started sampling at Bayberry in April.

The fish & DO story was different at the three other Magothy sites I sample, and the news was not good.

At the first two these sites, Ulmstead in the mouth of Forked Creek and in my own neighborhood (Stewarts Landing) on Old Man Creek, the bottom DO was less than 1 mg/l at both sites, but that’s fairly common in the summer.  There were no weird colors or smells, and people were fishing or crabbing in shallow water nearby, although not in water as deep as where I sample.

However, in upper Cattail Creek in Berrywood, the water was a weird milky green and there was a musky smell, so I knew before I lowered the meter that the DO would be bad.  The color and the smell are both signs of an algae bloom that died and is decomposing.  The surface DO was only 0.7 mg/l, the second lowest surface DO reading I've ever made, and the bottom DO was definitely anoxic with 0.00 mg/l, the lowest DO meter reading I’ve ever seen.  My granddaughter can't quite read numbers yet, but she knows zero when she sees it. It made me sad to show her how dead the creek was.  Amazingly there were no signs of any dead fish; I think the fish usually avoid the whole upper creek when it's such a dead zone.  I’ve never seen anyone fishing or crabbing nearby.  A week after I sampled there, Cattail Creek had a health advisory against swimming posted by the county health department for high bacteria levels, so that creek has multiple problems.

The water quality in these creeks was not always this dismal. Both Cattail and Old Man creeks were much healthier in 2004 and 2005, when dark false mussels covered almost all of the hard surfaces over a variety of depths in both creeks. By pure luck, when I chose my sampling sites in 1991 I picked two sites that would have some of the densest mussels 13 years later, so I have been able to document the water quality improvements that followed their filtration. Water clarity (measured by Secchi depth) and bottom dissolved oxygen showed dramatic improvements in both creeks in those years, and underwater bay grass (SAV) acreage in the Magothy went up in both 2004 and 2005.  Volunteer divers and kayakers organized by Dick Carey of the Magothy River Association estimated the number of mussels and the volume of the creek. From that research they estimated that, in 2004, the mussels could filter the water in Cattail Creek every two days, while it took them 15 days in 2005. (Watch an eight-minute video about the mussels and the 2004 surveys.) Imagine how healthy the Bay would be if oysters were filtering its water every two days, or even every 15 days. 

People who remember the mussels from 2004 keep asking me how we can get them back, along with improved water quality.  I don’t have an easy answer.  Memories of the mussels do give me hope that improvement is possible.  I just wish the mussels and the good water quality were still here to show my granddaughter, instead of zeroes on the DO meter.

About Peter Bergstrom - Peter Bergstrom is a biologist with the National Oceanic and Atmospheric Administration (NOAA) Chesapeake Bay Office.



Jul
13
2009

Battle for the Bird River

I’m declaring war. No, I’m not assuming some pseudo-political position giving me the power to aggregate our country’s resources in a fight for power, peace or anything else dominating the headlines these days. I, Liana Vitali, am declaring war and all the power I need is the strength in my arms and a Sea Doo GTI with a 130 hp engine and a sleek, ergonomic design. Combine this with my steadfast desire to restore the Chesapeake Bay to its historic and unimaginable beauty and you’re looking at a stealthy invasive species destroyer, equipped to rid the Chesapeake Bay of its exotic aquatic vegetation invaders and able to leap tall buildings in a single bound! (OK, that part might be an exaggeration.)

I bet you’re wondering who I used my incredible skills and power to wage war upon . . . the dreaded Trapa natans. Here is its criminal rap sheet:

CONFIDENTIAL
Street name: Water Chestnut
Continents of Origin: Europe, Asia and Africa
Last Known Chesapeake Bay Residence: Bird and Sassafras rivers
Criminal Record: Convicted on multiple accounts of:
  • Aggravated assault on native underwater Bay sea grasses
  • Possession of a weapon in the form of ½ inch spikes sharp enough to cut through shoe leather
  • Aiding and abetting by creating an environment conducive to the growth and cultivation of blood-sucking mosquitoes

Recently, I joined forces with Maryland Department of Natural Resources biologists to seek and destroy water chestnut in the Bird River, north of the city of Baltimore. We deployed one Carolina skiff and two Sea Doos to scour the shores of the entire main river and creeks. This time last year, we worked collectively to remove what seemed like half a ton of water chestnut from the river. This year, we returned to find that the skills, strategy and no doubt awesome intimidation we imposed on the invader must have struck fear into its very roots. Though their guerilla tactics of hiding amongst beloved native water lilies nearly out of sight might have worked, they clearly misjudged our abilities and dedication to the Bay. One by one, we yanked out less than a quarter of the water chestnut we removed last year. OohRah!

So does this mean that I can now hang a large and lovely banner across the front of the Chesapeake Bay Program building proudly stating “MISSION ACCOMPLISHED!”? No. But can I proudly say we’ve set an example of how combining manpower and resources with a loyal devotion for the Chesapeake Bay can result in tangible and positive changes to our creeks and rivers? Absolutely.

 

About Liana Vitali - Liana Vitali was a Living Resources Subcommittee staffer with the Chesapeake Research Consortium at the Chesapeake Bay Program.



Keywords: invasive species
Jul
01
2009

Washington, D.C., bans use of coal-tar pavement products containing toxic PAHs

Washington, D.C., has banned the use and sale of coal-tar pavement products to curb the flow of a toxic chemical contaminant called polycyclic aromatic hydrocarbons (PAHs) to the Anacostia River, Potomac River and Chesapeake Bay.

Coal-tar pavement sealers, which are commonly used to seal asphalt driveways and parking lots, are a major source of PAHs. The dust from parking lots sealed with coal tar has more than three times the concentration of PAHs as undiluted used motor oil, which is considered a leading source of PAHs. Other sources include auto exhaust, tire particles and broken-up asphalt.

A recent scientific study by the U.S. Geological Survey showed that PAH concentrations in dust from parking lots sealed with coal-tar products are about 80 times higher than in dust from unsealed parking lots. In D.C., rain washes these toxic PAHs from coal-tar sealant off paved surfaces and into the streams and creeks that flow to the Anacostia River, the Potomac River and the Chesapeake Bay. Research suggests that total PAH loads washed off parking lots could be reduced by as much as 90 percent if parking lots were left unsealed.

PAHs have been shown to cause cancerous tumors in animals, even in single doses. Non-cancerous health effects can include immune system suppression and red blood cell damage. In fish and invertebrates, adverse health effects have included cataracts, fin erosion, liver and reproductive abnormalities, and even death.

In the Anacostia River, scientists have discovered high rates of PAH-related lesions and tumors on bottom-dwelling fish. In one Fish and Wildlife Service study, 50 to 60 percent of collected fish had liver tumors. Tests suggested that PAH exposure was likely responsible for the tumors.

“It’s rare that we have a chance to knock out this kind of pollution in one fell swoop,” said George S. Hawkins, director of the D.C. Department of the Environment. “Now that we’ve discovered what’s in coal tar and what it does, we have a rare opportunity to protect our waterways relatively easily.”

The coal-tar pavement product ban took effect on July 1. Learn more about the ban at the District of Columbia’s website.



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