A small stand of trees along the bank of the Severn River is part of the solution for what ails the Bay, noted EPA Bay Program Director Jeff Lape on an overcast morning in early April.
It would likely rain soon, but the runoff from a nearby road would pass through the 10-year-old buffer, where much of the rain would be filtered and much of the pollutants it carried, trapped.
If all areas along the Bay and its tributaries had buffers, he noted, "we would see a major improvement in the health of our water resources."
Such restoration efforts need to be stepped up, Lape said, as he announced the release of the annual Chesapeake Bay Health and Restoration Assessment. It showed that just 12 percent of the Bay and the tidal portions of its tributaries met dissolved oxygen and water clarity goals, while key habitats such as underwater grass beds remained far below restoration goals.
Data in the 2007 Bay Program report show that most habitats remain below goals or are in decline, and target fish species-except striped bass-are in poor condition, although shad show signs of rebounding in some rivers.
"It's easy to see from this data that much more needs to be done to accelerate the pace of implementation if we are to succeed in cleaning up the Bay and its rivers," Lape said. "Not only do we need major actions to accelerate implementation, but we also must grow smarter and greener to protect our local waterways and the Bay."
The report said some positive restoration efforts have taken place-such as fish passages, underwater grass plantings and upgrades to wastewater treatment plants-but the overall water quality which drives the health of the ecosystem remains largely unchanged over the last two decades.
Only 12 percent of the Bay meets water clarity goals-a situation that has been getting progressively worse since the mid-1980s, when 40 percent achieved water clarity goals. That's bad news for underwater grasses, as well as for aquatic predators that require clear water to find their prey.
The report shows that the Bay still suffers from a massive overload of nutrients, especially nitrogen. It estimates that about 318 million pounds of nitrogen reached the Chesapeake in 2007-just a bit less than the average 350 million pounds a year that's entered the Bay since 1990.
That's almost double the 175 million pound annual goal.
"The Bay continues to be bombarded by excess nitrogen, which contributes to harmful algal blooms and low oxygen levels for fish and crabs," said Carlton Haywood, chair of the Bay Program's Monitoring and Assessment Subcommittee and director for program operations at the Interstate Commission on the Potomac River Basin. "This trend is eroding the Bay's resiliency and must be reversed."
The news was better for phosphorus. In 2007, about 15 million pounds entered the Bay. That's significantly less than the 27 million pounds that entered the Bay in the mid-1980s, but still more than the 12.8 million pound goal.
The two nutrients fuel algal growth in the Bay, which blocks sunlight needed for underwater grasses, one of the most important habitats in the Chesapeake. When the nutrients die, they sink to the bottom and are decomposed in a process that depletes the water of oxygen.
The lack of significant nitrogen reductions is a sign that some of the ongoing nutrient reduction efforts are being offset by human activities.
For instance, the report said agriculture had achieved 48 percent of its nitrogen and 51 percent of its phosphorus goals, while wastewater treatment plants had achieved 69 percent of their nitrogen and 87 percent of their phosphorus goals.
But other activities are hurting the Bay's water quality.
In recent years, high commodity prices have resulted in a more intense use of agricultural land, as farmers have grown more acres of corn, which can produce large amounts of nutrient-laden runoff-actions that threaten to offset other agricultural nutrient reduction activities.
"That is a very real issue because corn really does transport a lot of nitrogen in runoff," Lape said.
Meanwhile, the watershed population has grown from 13.5 million to 16.7 million people. Development has increased at an even faster pace: From 1990-2000, the amount of impervious cover-roads, parking lots and rooftops-increased at a rate five times faster than population growth.
"Each year we have 150,000 people moving into the watershed, bringing more pavement, roads, roofs and lawns," Lape said.
The report noted that more than 750,000 acres of forest land, which yields less nutrient and sediment runoff than any other land use, has been lost in the Bay watershed since the mid-1980s.
Other factors such as climate change make restoration more problematic, the report noted. Sea level rise causes increased shoreline erosion which results in more sediment clouding the water. Increased river flows and warmer water temperatures can also increase algae growth and reduce the amount of oxygen in the water.
Lape expressed confidence that the state-federal Bay Program partnership was up to the challenge of restoring the Bay.
But, he cautioned, "I want to be real careful that when we say there has been some improvement from one year to the next that we not give people the impression that this Bay just turns on a dime. It took 400 years to get to this condition."
The full Chesapeake Bay Health and Restoration Assessment, as well as supporting information, is available on the Bay Program's web site, www.chesapeakebay.net.
Key Indicators Of Bay Health
To determine ecosystem health, the Chesapeake Bay Health and Restoration Assessment evaluates 13 water indicators of water quality, habitats and key fish and shellfish species:
Dissolved Oxygen: Species living in various parts of the Bay need different amounts of dissolved oxygen to survive; worms living in bottom sediment need small amounts of oxygen, while striped bass living near the surface need much higher concentrations. Last summer, only 12 percent of the Bay and its tidal tributaries contained enough oxygen to support species that should be found in different habitats.
Water Clarity: Twelve percent of the Bay's waters achieved water clarity goals in 2007. Clear water is essential for underwater grasses to survive, and for fish and other predators to be able to find their prey.
Chlorophyll a: This is a measure of algae near the surface of the Bay. Some algae is important to fuel the Bay's food web, but excess concentrations block sunlight to underwater grasses, contribute to low dissolved oxygen concentrations, and can lead to blooms of harmful algae species. In 2007, 26 percent of the Bay met cleanup goals.
Chemical Contaminants: Thirty-three percent of the Bay's waters are free of impairments caused by toxic pollutants in 2007, such as excessive concentrations in sediments or high enough concentrations in fish tissue to lead to consumption advisories.
Bay Grasses: The Chesapeake had about 65,000 acres of underwater grasses in 2007, or 35 percent of the 185,000 acre restoration goal. Grass beds are one of the most important parts of the Bay ecosystem, helping to filter the water and providing habitat for a host of species, from juvenile blue crabs to waterfowl.
Bottom Habitat: About 43 percent of the bottom areas of the Bay supported healthy communities of benthic organisms such as worms and clams. Because these organisms have only a limited ability to move, their health is considered a good indictor of environmental conditions.
Phytoplankton: A healthy mix of algal species is important for the Bay's food web, while blooms dominated by a single species can be harmful. Data from spring 2007 indicate that 55 percent of the Bay's phytoplankton communities were considered healthy.
Wetlands: As of 2005, the Bay had an estimated 283,946 acres of tidal wetlands, a decline of 2,600 acres from a decade earlier. Tidal wetlands are important habitats, and also help to absorb runoff and filter pollutants. They are threatened by sea level rise, climate change, shoreline development and invasive species. Right now, the Bay Program does not have a specific tidal wetlands goal.
Fish & Shellfish
Blue Crabs: The 2007 blue crab population was about 78 percent of the 200 million blue crab interim target. Overall abundance continues to be low, and the stock has not shown signs of rebounding. They are the Bay's most valuable commercial species today.
Striped Bass: Rockfish continue to exceed restoration goals. But concerns remain about the species' health because of the high prevalence of mycobacteriosis, a chronic wasting disease, among the population.
Oysters: The region has achieved 8 percent of its goal of a tenfold increase in oyster populations, measured from a 1994 baseline. Oysters are a critical species because they help to filter the water and provide habitat for a host of other species. Their populations are near historic lows because of overharvesting, disease and poor water quality.
Shad: Twenty-two percent of the Baywide shad restoration goal has been achieved, although success varies widely among rivers. The Potomac has achieved 67 percent of its goal, and the York 38 percent, while the Susquehanna River has reached only 0.01 percent of its population goal and the James River, 0.02 percent. Shad once supported the most valuable commercial fishery in the Bay.
Menhaden: The number of juvenile menhaden in the Chesapeake Bay has been below average for the last 14 years. Menhaden are an important source of food for larger fish such as striped bass, and are also valued for their ability to filter the water. Right now, the Bay Program does not have a goal for menhaden.