2005-004-FA_SAMPLES.SHP: Sediment sample and textural properties at 40 sample locations collected by the U.S. Geological Survey in Moultonborough Bay, Lake Winnipesaukee, New Hampshire in 2005 (Geographic, WGS 84, Esri point shapefile)

In freshwater bodies of New Hampshire, the most problematic aquatic invasive plant species is Myriophyllum heterophyllum or variable leaf water-milfoil. Once established, variable leaf water-milfoil forms dense beds that can alter the limnologic characteristics of a waterbody, impacting natural lacustrine communities and their habitats. Variable leaf water-milfoil infestations also disrupt recreational uses of waterbodies and have negatively affected swimming, boating, fishing, and property values in and around several lakes and ponds in New Hampshire.

In 1965, Moultonborough Bay, Lake Winnipesaukee became the first waterbody in New Hampshire where variable leaf water-milfoil was observed. Variable leaf water-milfoil is native to the Southeastern and Midwestern areas of the United States where more alkaline waters appear to limit the growth of this plant. Outside its native range, however, it adapts well to the relatively acidic, low-alkalinity, and nutrient-poor conditions of oligotrophic lakes and bays similar to Moultonborough Bay.

In 2005, the New Hampshire Department of Environmental Services (NHDES) collaborated with the U.S. Geological Survey to investigate the distribution (presence and density) of variable leaf water-milfoil in Moultonborough Bay. This study utilized geophysical systems and conventional water-quality measurements to identify lake-floor environments that may provide suitable habitat for the establishment and growth of variable leaf water-milfoil. The results of the study are intended to assist resource managers in federal and state agencies by providing methods for detecting variable leaf water-milfoil and for identifying areas susceptible to infestation. Ultimately, this information may lead to early detection, prevention, and more effective mitigation strategies.

新罕布什尔州的淡水水体中，危害最突出的水生入侵植物物种为异叶狐尾藻（Myriophyllum heterophyllum），俗称可变叶狐尾藻（variable leaf water-milfoil）。该物种一旦成功定殖，便会形成茂密的植株群落床，能够改变水体的湖沼学特征，进而干扰自然湖泊群落及其栖息生境。可变叶狐尾藻的入侵还会破坏水体的休闲使用功能，对新罕布什尔州多座湖泊及池塘周边的游泳、划船、垂钓活动及房产价值均造成了负面影响。
1965年，新罕布什尔州温尼佩绍基湖（Lake Winnipesaukee）的莫尔顿伯勒湾（Moultonborough Bay）成为该州首个发现可变叶狐尾藻的水体。可变叶狐尾藻原产于美国东南部与中西部地区，当地偏碱性的水体似乎会限制该植物的生长。但在其原生分布范围之外，该物种能够很好地适应寡营养（oligotrophic）湖泊及海湾中偏酸性、低碱度且营养匮乏的环境，这类环境与莫尔顿伯勒湾的条件相似。
2005年，新罕布什尔州环境服务部（New Hampshire Department of Environmental Services, NHDES）与美国地质调查局（U.S. Geological Survey）合作，针对莫尔顿伯勒湾内可变叶狐尾藻的分布（存在情况与种群密度）开展了调查。本研究借助地球物理探测系统与常规水质测量手段，识别出可为可变叶狐尾藻定殖与生长提供适宜生境的湖底环境。该研究结果旨在为联邦及州级机构的资源管理者提供支持，通过提供可变叶狐尾藻的检测方法以及易受入侵区域的识别手段。最终，这些研究成果可推动早期检测、入侵预防及更高效的防控缓解策略的制定。