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Water Quality and the Chesapeake Bay David O’Brien NOAA Fisheries Service Gloucester Point, VA
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Chesapeake Bay The nation’s largest estuary Nation’s most biologically diverse estuary; >3600 species of plants and animals Over 17 million people live in the watershed
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Chesapeake Bay watershed Virginia Maryland Pennsylvania New York Delaware West Virginia Dist. Columbia
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What Is a Watershed?
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Adapted from NEMO Water-vapor transport Ocean Infiltration Increased runoff Decreased Less groundwater flow Lower water table Evaporation Less vegetation, thus less evapotranspiration!! Increased pollution The Water Cycle Development: Increased impervious surface
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Ches Bay Population Growth 2010 - 17.2 million
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Threats to the Chesapeake Bay N UTRIENTS S EDIMENTS T OXIC CHEMICALS H ABITAT LOSS O VERFISHING
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Chesapeake Bay: How is it Doing???
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Habitat Conversion
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Watershed development % impervious surface
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Water Quality Problems Algae blooms and sediment cloud the water and block sunlight, causing underwater bay grasses to die. When the algae die and decompose, they use up oxygen needed by other plants and animals living in the Bay's waters. Algae blooms and depleted oxygen levels are caused by excessive nutrients Poor water clarity is caused by algae blooms and suspended sediments
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Impaired Waters EPA 303(d) list Portions of the Chesapeake Bay and its tidal rivers are listed under the Clean Water Act as “impaired waters” largely because of low dissolved oxygen levels and other problems related to nutrient pollution. This “listing” requires the development of a clean-up plan for the Bay by 2011. Impaired Water Note: Representation of 303(d) listed waters for nutrient and/or sediment water quality impairments for illustrative purposes only. For exact 303(d) listings contact EPA (http://www.epa.gov/owow/tmdl/). Unimpaired Water Nutrient and/or Sediment Impaired
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Harmful Algal Bloom (HAB) HRBT y
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HAB Lafayette River
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Healthy vs. Unhealthy Water Quality Sunlight Healthy Habitat Unhealthy Habitat Balanced Algae Growth Minimal nutrient and sediment inputs Excessive nutrient and sediment inputs Healthy Bay Grasses Reduced Bay Grasses Algae Die-off Algae Decomposition No Oxygen No Benthic Community Benthic Community Healthy Oyster Reef Adequate Oxygen Algal Bloom Barren Oyster Reef
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Chesapeake Bay DO 2006-2009
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Sources of Pollutants to the Bay Nonpt. Sources Run-off from farmland Run-off from lawns and paved areas Point Sources Industry Wastewater Treatment Plants
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Nature of Contaminant Inputs Point Source Inputs with well defined point of discharge Discharge is usually continuous Nonpoint Source Origin of discharge is diffuse Discharge may be transient in time Runoff from cropland Effluent from septic systems Highway de-icing salts Leakage from landfills and storage tanks Wastewater treatment facilities Industrial inputs
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Sediment Nutrients Toxic Substances Pathogens Non-point Source Pollutants
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Hurricane Irene sediment plume Sept. 14, 2011
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Nutrient and Sediment Load Reduction Goals The 2010 pollutant reduction goals are: Nitrogen - Reduce annual loads to no more than 175 million pounds. Phosphorus - Reduce annual loads to no more than 12.8 million pounds. Land-based Sediment - Reduce annual loads to no more than 4.15 million tons. 2010 Phosphorus Goal 2010 Nitrogen Goal 2010 Sediment Goal
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Nitrogen Loading
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Phosphorus Loading
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Chesapeake Bay Water Quality Goals 2009
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Water Clarity
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Dissolved Oxygen (DO)
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Wetland restoration
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Chesapeake Bay Fish / Shellfish Goals 2009
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Rockfish Population Stable Rockfish have rebounded to levels not seen since the 1950’s, but concerns remain over disease, sufficient sources of food and availability of spawning habitat. Fishing moratoria: MD & DE: 1985-1990 VA: 1989-1990 Baywide Female Spawning Stock Biomass
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Striped Bass
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Oysters at Historic Lows Oyster populations in the Chesapeake are at historic lows due to disease, intense harvest pressure and poor water quality.
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Oyster stocks
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Oyster restoration efforts
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Blue Crabs At Risk Mature Female Blue Crabs Average Blue Crab populations have stabilized at below- average levels. Improved water quality and habitat restoration efforts along with proper management of the crab harvest are needed to restore the Bay’s blue crab populations.
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Blue Crab Largest crab fishery in the world $80 million dockside value in Ches Bay $360 million value to national economy
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Blue Crab stock
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SAV 2007-2009 goals
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Bay Grasses Show Annual Variation Underwater bay grasses are slowly improving, but further reductions in the pollutants flowing into the Bay are needed to help them flourish. Annual variations in bay grasses show the sensitivity of the Bay ecosystem. Restoration Goal (185,000 acres by 2010) *Note – Hatched area of bar includes estimated additional acreage. No Baywide surveys 1979-83 and 1988 Source: Chesapeake Bay Program.
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SAV aerial coverage
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PRE-1930’S1960’SPRESENT
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Clam Dredge Scarring in Chincoteague Bay
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SAV Restoration - Planting
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Special thanks to: Dr. Bob Orth, VIMS SAV Program Chesapeake Bay Program Chesapeake Bay Foundation NOAA Chesapeake Bay Office
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Thanks for your interest!!!
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