August 23, 2006
Residents Attack Invasive Species
When someone or something invades their turf, one thing's for certain: Riverhead residents band together to fight the enemy.
Or, at least, scores of volunteers step up when the intruder is an invasive plant that is threatening the Peconic River ecosystem and the rich recreational opportunities, such as fishing, canoeing and kayaking that abound at one of the East End's most beloved natural resources.
Last Saturday, over 50 volunteers brought their goodwill and elbow grease to the Peconic Lake Estates Civic Organization property in Calverton for a removal event geared at ridding the Peconic River of water primrose (Ludwigia peploides), an invasive plant native to South America and first seen in Peconic Lake on the Peconic River in 2003.
Back in May, Shana Miller, of the Peconic Estuary Program, addressed the Riverhead Town Board to discuss the insidious species. Before its discovery in the Peconic River, only one other case of water primrose had ever been found in the New York area, in Brooklyn's Prospect Park. "It's a unique problem," she said.
Water primrose, known commonly by its scientific name Ludwigia peploides, is an invasive aquatic perennial that has found its way into many waterways, most notably throughout France, and is now an emerging concern in the United States.
Since the arrival of the water primrose in the Peconic River, dense mats of vegetation have made boating and fishing nearly impossible.
Water primrose thrives in ditches, riverbanks, ponds, slow-moving streams and along margins of lakes and reservoirs. The major growth requirement for this species is submerged roots.
The water primrose poses many ecosystem threats due to its rapid and extensive growth. French studies indicate that water primrose are able to double their biomass in 15 to 20 days in slow-flowing waters and in about 70 days in rivers.
Water primrose also reduces biodiversity and degrades water quality by decreasing PH and dissolved oxygen content. Because its leaves are above the water surface, Ludwigia does not add much oxygen to water and shades out submerged plants below that could add oxygen to the water.
Those unfamiliar with water primrose would recognize the floating aquatic perennial herb of the evening primrose, or Onagraceae, family, because of the mat formations. Flower-bearing stems are weakly upright with lance-shaped leaves. Stems are purple and have little to no hair. They are rooted, but most of the stem floats on the surface of the water.
Experts say that because water primrose poses such a threat, it must be pulled manually before it establishes a large colony, adding that it is wise to place filters downstream from the infestation before pulling to prevent the further spread of the species.
In an effort to put the brakes on the invasive species, the PEP received a $26,000 grant from the New York State Department of Environmental Conservation to hand-pull the rooted aquatic plant, said Miller.
Miller approached the board because a permit was needed from the DEC before hand-pulling could begin on the Peconic River in Riverhead — to apply for the permit, Riverhead, as the underwater landowner, was required support the initiative.
Time was of the essence, insisted Miller, who said the water primrose is spreading rapidly and is down to Grangebel Park. "If we wait too long, hand-pulling won't be an option," she said. "We don't want to use pesticides."
The board acted quickly and gave the project the green light.
Miller said the PEP would use boats and that the best months for removal are June and August; the first removal event was held in June.
Last Saturday's event was attended by experts from the PEP, The Nature Conservancy, the DEC, local residents, fishermen and canoeists who used power boats, row boats and waders to help yank the species from the water. After removal, plants were transferred to a dumpster for transport to a composting facility to ensure environmentally sound disposal.
Laura Stephenson, of the Peconic Estuary Program, said the effort was a grand-slam success, resulting in the removal of "about 40 cubic yards" of water primrose, "double" the amount removed from the first event. Next year, she promised, an even bigger effort would be embarked upon.
"Something really needed to be done and so many people came out and volunteered their time for such a great cause," she said.