Suzanne Petersen, education specialist
Lamprey River Advisory Committee
Many researchers, community planners, environmental specialists, and concerned citizens gathered recently for the State of the Estuaries Conference held October 16, 2009 in Somersworth. The focus of this gathering was to discuss Great Bay, the Hampton-Seabrook Estuary, and the greater coastal watershed. The bottom line from the conference was that our waters are showing increasing signs of trouble. In August 2009, NHDES determined that much of Great Bay and the lower Piscataqua River were impaired by elevated nitrate and bacteria levels and low dissolved oxygen. Declining eelgrass habitat and low numbers of oysters in Great Bay and the lower Piscataqua River were cited as indicators of declining biological integrity in the estuary. Such impairments of the estuary are often the consequence of impairments to the tributary rivers, of which the Lamprey is the biggest. Other impairments in the estuaries include mercury, PCBs, and dioxin.
First, let us define a few key words.
An estuary is a semi-enclosed body of water where fresh water from rivers meets salt water from the ocean. Estuaries have unique attributes that favor traditionally productive fisheries and shellfisheries. Pollution in an estuary comes from activities on land, the estuary itself, the atmosphere, and the ocean.A watershed is the land area surrounding a body of water whose boundaries are determined by the drainage of rainwater. Rain that falls on one side of a mountain may drain to one watershed and rain that falls on another side of the same mountain may drain to a different watershed. New Hampshire’s coastal watershed includes Candia to the west, Brookfield and Wakefield to the northwest, Seabrook to the south and Wells, Maine to the northeast. All the rain that falls on this area ultimately travels toward the ocean, picking up all the sewage, septic waste, excess fertilizer, eroded soils, petroleum drippings, etc. from the watershed along the way. The more natural and undeveloped a watershed is, the more water gets filtered by the soil, and the better the quality of water that reaches the river, lake, or estuary.
Nitrate is a water-soluble molecule composed of one atom of nitrogen and three atoms of oxygen. It is used by all living things and is released back to the environment when living things die or defecate. Nitrate is an important plant fertilizer. On land, and in small quantities, plants use nitrate to fuel growth. Plants can only take up a certain amount of nitrate, however; the excess is picked up and carried away by water. Nitrates most often occur in rivers and estuaries as a result of non-point source pollution. Non-point source pollution is hard to trace to a particular origin and it may come from multiple sources. Cumulatively, though, it far outweighs nitrates from point sources such as sewage treatment plants.
In streams, rivers, lakes, and estuaries, algae use nitrate to fuel their growth. In amounts above what is naturally available, such growth is usually harmful to the environment. Estuaries are especially vulnerable to nitrate pollution. Excessive algal growth causes the water to become murky and green, which lowers the depth that sunlight can penetrate. By day, the algae photosynthesize, but by night, these same plants consume oxygen gas dissolved in water for normal respiration. Further, when algae die, their decomposition by bacteria consumes even more dissolved oxygen.
In the summer when water is warm, gases such as oxygen do not dissolve well in water. Add the burden of algal respiration and decomposition to this situation of lower dissolved oxygen, and the result is water that has very little or no dissolved oxygen gas. Without dissolved oxygen, fish and shellfish cannot survive. Fish kills often occur in the summer where tidal rivers are polluted with nutrients. The Lamprey, Oyster, Salmon Falls, and Squamscot Rivers have been experiencing low dissolved oxygen levels in the last decade, and the frequency with which they occur is on the rise.
Nitrate can also cause direct harm to people in addition to the side effects of excessive algal growth. Nitrate in drinking water can cause “blue baby syndrome”, a sometimes deadly condition. Nitrates leach into ground water primarily through failed septic systems. Several wells in the Lamprey River watershed have nitrate concentrations that exceed safe limits. Few homeowners have the time or money to perform frequent water quality tests on their wells, so some people are drinking unsafe water.
Fecal coliform bacteria is a contaminant associated with untreated mammal and bird waste. It can come from improperly treated water from sewage treatment plants, dog waste left near streams or pavement, but it more commonly comes from failed septic systems. The presence of even small quantities of fecal coliform bacteria can render water unfit for shellfishing, swimming, and drinking. The Lamprey River and Great Bay have sites that exceed the safe limit.
Impaired is a designation or status that the government uses when a body of water does not meet federal quality limits under the Clean Water Act. Impaired water is not fit for drinking, swimming, and/or fishing. The designation brings with it a badge of failure, and sanctions, up to and including fines and mandatory mitigation.
First, our land use practices and the increasing population in southeast New Hampshire and southern-most Maine are causing harm to our waters and to us. Everything we do on our land affects our water. Second, all of us, from Wakefield to the seacoast, must address these issues. We must work together, not only as towns or counties or even states, but as citizens of our shared watershed. Our water connects us all, across town lines and state lines. What happens far inland and away from any significant stream has effects on the seacoast. New Hampshire and Maine have agreed to work together and our towns must agree to work together, too. Our communities have been given a political mechanism to address our common water issues through the newly formed Southeast Watershed Alliance.
Our towns must be vested in reaching common goals, but as individuals we all must also be vested.
Our rivers and estuaries are great resources for all of us. Unfortunately, they cannot provide for us indefinitely if we continue to subject them to the demands we currently place upon them. In most cases, these water resources can function well if we choose to permit them to keep their natural attributes and systems: free flow, abundant vegetated ground cover, wetlands, etc.. It should be an easy choice to make. Natural systems are beautiful as is and do not require significant effort on our part. In almost every case, natural systems are more economical and efficient than human-designed landscapes. After presenting the woes of the estuaries, the State of the Estuaries report did indicate progress toward the goal of protecting land in the watershed. As of 2008, 11.3% of the watershed was protected from development. The goal of protecting 15% will help provide benefits that come from natural landscapes.
The Lamprey River Advisory Committee, which administers the federal Wild and Scenic River Program for the Lamprey, continues to make land protection its priority. The LRAC has tripled the federal land protection funds it receives through partnerships and grants to protect almost 2,000 acres and more than eleven miles of river front. Landowners interested in protecting their land from development in the river corridor and, thus helping to protect Great Bay, should contact Sharon Meeker at email@example.com. Please also visit the LRAC website at www.lampreyriver.org.
The full report of the “State of the Estuaries 2009” can be downloaded at www.prep.unh.edu or by contacting the Piscataqua Regional Estuaries Partnership at 603-862-3403, or PREP, University of New Hampshire, Nesmith Hall, 131 Main St., Durham, NH 03824-2601.