2005-004-FA_VIDEOTRK.SHP: Trackline navigation for video data from 40 sample locations collected by the U.S. Geological Survey in Moultonborough Bay, Lake Winnipesaukee, New Hampshire in 2005 (Geographic, WGS 84, Esri polyline 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variable leaf water-milfoil）。该物种定植后会形成茂密的植株群落，能够改变水体的湖沼学特征，进而影响自然湖泊群落及其栖息生境。异叶狐尾藻的入侵滋生还会破坏水体的休闲使用功能，对新罕布什尔州多处湖泊及池塘及其周边区域的游泳、划船、垂钓活动以及房产价值均造成负面影响。

1965年，温尼佩绍基湖（Lake Winnipesaukee）的莫尔顿伯勒湾（Moultonborough Bay）成为新罕布什尔州首个发现异叶狐尾藻的水体。异叶狐尾藻原产于美国东南部和中西部地区，在这些区域内，碱性较强的水体似乎会抑制该植物的生长。但在其原生分布范围之外，该物种能够很好地适应类似莫尔顿伯勒湾的贫营养湖泊及海湾的相对酸性、低碱度且养分匮乏的生境条件。

2005年，新罕布什尔州环境保护部（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异叶狐尾藻的分布（包括其存在范围与种群密度）开展了调查。本次研究采用地球物理探测系统与常规水质监测手段，识别出了可能适宜异叶狐尾藻定植与生长的湖底生境环境。本研究结果旨在为联邦及州级机构的资源管理者提供检测异叶狐尾藻以及识别易受入侵滋生区域的方法，从而助力相关管理工作。最终，该研究成果可助力实现早期监测预警、入侵预防以及更高效的治理防控策略。