Dick Pinney's Guide Lines: Nutrients overload Seacoast watersheds
March 22. 2014 1:03AM
THE canary in the mine is dead or dying, and we sincerely hope it's not too late for us humans to do something quickly to stop a catastrophe from happening.
The "canary" is the Great Bay and Piscataqua River's eelgrass and saltwater smelt population, and the cause, rather than the toxic air of the mine, is the overload of nutrients in the watershed - mostly nitrogen.
We here in New Hampshire are not alone. Maine's almost total loss of its saltwater smelt population puts it in the same situation. There's no doubt other factors beside the nutrient loading of our watersheds contribute to the nitrogen content of the water - and we do have some control over this, although the clock is ticking fast, so we can't waste any time in improving water quality.
Imagine about 2,000 area toilets flushing their nitrogen-loaded packages into the Piscataqua River with little treatment other than the screening of large solids and settling out of small solids. Then, more poison: a shot of chlorine, which could be removed from the slurry but is left in the discharge.
Well, the City of Portsmouth has about 2,000 hotel rooms alone, not to mention all the rest of the toilets in homes and businesses adding to the huge outflow. Add other methods of producing nitrogen that now goes through our sewers and, after hardly any effective treatment, on into the river, and the damage is even worse.
And let's not forget about several other cities and towns in Maine and New Hampshire that also empty their nitrogen-rich soup to the watershed.
Why is nitrogen to blame? Because its effectiveness as a fertilizer enables just about every living thing - other than animals - to grow and flourish.
Eelgrass beds are vital for keeping things such as sediment in check as they anchor the sediment to their roots. They keep silt beds in check and provide both food and cover for many marine species. It's said that just about every thing that lives in the ocean receives some kind of beginning or help from our tidal estuaries. Here in New Hampshire and Maine, there are plenty of examples of this.
Four things that come to mind that have suffered from overloads of nitrogen in these estuarine environments are waterfowl, smelt, oysters and clams, with the smelts looking like they are already hearing their death knoll. Oysters seem to use nitrogen, but the impact on them from polluted discharge that includes nitrogen is the siltation, caused by loss of eelgrass, that covers the oyster beds and smothers them.
Nitrogen overloads in our waters have been preventing the growth of eelgrass and, in many cases, have killed acre upon acre of productive eelgrass beds.
We live right on the shoreline of Great Bay and have witnessed the loss of eelgrass with our own eyes. Like any other kind of grass, eelgrass needs sunlight to live and flourish. The overload of nitrogen and the increase in sediment, both in suspension and covering the bottom, have filtered out the sunlight and killed the eelgrass. Without eelgrass, the sediment load will increase tremendously, so you could say that it's a downward spiral.
But it can be stopped if we react quickly enough. The Great Bay and Piscataqua River "Waterkeeper" program, which is part of a worldwide Waterkeeper Alliance of 214 waterkeepers, is funded and instituted by the Conservation Law Foundation. Our own waterkeeper, Jeff Barnum of York, Maine, seems to be on the right track in getting as many people and businesses onboard to try to put a stop to this very slippery slope. We're on board with Jeff and several other dedicated conservationists to get this movement off its blocks. You can reach Jeff at firstname.lastname@example.org. We suggest that you send him an email and offer some help. It's getting to be a very desperate window of opportunity to get the job done.
Dick Pinney's column appears weekly in the New Hampshire Sunday News. Email him at DoDuckInn@aol.com.