2009 State of the Estuaries Report Reveals Signs of a Declining Coastal Environment
By Dave Kellam, Piscataqua Region Estuaries Partnership
October 28, 2009
In Great Bay, the concentrations of dissolved inorganic nitrogen, a major component of nutrient loading to the system, have increased by 44 percent in the past 28 years. The negative effects of the increasing nutrient loads are evident as water clarity has declined and eelgrass habitat in the estuary has disappeared from the tidal rivers, Little Bay, and the Piscataqua River. Image courtesy of Fred Short, UNH.
A new report from the Piscataqua Region Estuaries Partnership (PREP) concludes that the environmental quality of the Piscataqua Region estuaries is declining. Eleven of 12 environmental indicators show negative or cautionary trends – up from seven indicators classified this way in 2006.
PREP is a program based at UNH that collaborates with governmental agencies, researchers, conservation organizations, businesses, and the public to implement a management plan to protect, restore, and monitor the region’s coastal watersheds. The program is primarily funded by a grant from the US Environmental Protection Agency.
The most pressing threats to the estuaries relate to population growth and the associated increases in nutrient loads and non-point source pollution.
• Each year, about 2.3 square miles of undeveloped fields and forests in the coastal watershed are converted into roads, parking lots, and/or buildings, dramatically reducing the ability of the land to retain and clean polluted runoff from rainwater and melting snow before entering the estuary. Sprawling development patterns, which are typical in much of the watershed area, add more developed areas per person than approaches that include compact development or conservation subdivision designs.
• In Great Bay, the concentration of dissolved inorganic nitrogen, which can be harmful at high levels, has increased by 44 percent in the past 28 years. The negative effects of this on the estuary system are evident in the decline of water clarity, eelgrass habitat loss, and failure to meet water quality standards for dissolved oxygen concentrations in tidal rivers.
Other indicators that suggest a declining environment include historically low oyster and clam populations, toxic contaminants present in nearly 25 percent of estuarine sediments, increased prevalence of petroleum-based contaminants in Piscataqua River shellfish, poor migratory fish returns, and continued beach and shellfish bed closures due to bacteria pollution.
The report highlights one area of environmental improvement. By the end of 2008, 76,269 acres (11.3 percent of the watershed) were permanently protected from development. These undeveloped lands provide critical habitat for wildlife and help prevent further water quality degradation.
PREP publishes a State of the Estuaries report every three years to communicate the status and trends of key environmental indicators for the Great Bay and Hampton-Seabrook estuaries and the Piscataqua Region watersheds. Public Service of New Hampshire provided funding to PREP to produce this year’s report.
The 2009 State of the Estuaries Report may be viewed at www.prep.unh.edu.