2005-004-FA_SONARTRK: Klein 3000 sidescan-sonar survey lines collected in Moultonborough Bay, Lake Winnipesaukee, New Hampshire by the U.S. Geological Survey 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.

在美国新罕布什尔州的淡水水体中，危害最为严重的水生入侵植物物种为异叶狐尾藻（Myriophyllum heterophyllum，variable leaf water-milfoil）。一旦成功定殖，异叶狐尾藻会形成密集草床，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环境。此外，异叶狐尾藻的入侵还会干扰水体的休闲使用功能，对新罕布什尔州多个湖泊及池塘周边的游泳、划船、垂钓活动以及房产价值均造成了负面影响。

1965年，温尼佩绍基湖的莫尔顿伯勒湾成为新罕布什尔州首个记录到异叶狐尾藻的水体。该物种原产于美国东南部与中西部地区，在这些区域，较高碱性的水体似乎会抑制其生长。但在原生分布范围之外，它能够很好地适应与莫尔顿伯勒湾类似的贫营养湖泊及海湾的相对酸性、低碱度且营养匮乏的生境。

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异叶狐尾藻的分布（存在情况与种群密度）开展了调查研究。本研究采用地球物理探测系统与常规水质测量方法，识别出可能适宜异叶狐尾藻定殖与生长的湖底生境类型。本研究成果旨在为联邦及州级机构的资源管理人员提供异叶狐尾藻检测以及易入侵区域识别的方法，从而助力相关管理工作。最终，这些研究成果可推动早期检测、入侵预防以及更高效的治理策略的制定与实施。