Survey tracklines of swath bathymetry collected by the U.S. Geological Survey in Moultonborough Bay, Lake Winnipesaukee, New Hampshire in 2005 (Geographic, WGS 84, Esri polyline shapefile, 2005-004-FA_BATHYTRK.SHP)

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. Field activity information for this cruise is available on-line through the U.S. Geological Survey Coastal and Marine Geoscience Data System https://cmgds.marine.usgs.gov/fan_info.php?fa=2005-004-FA.新罕布什尔州的淡水水体中，危害最严重的水生入侵植物物种为异叶狐尾藻（Myriophyllum heterophyllum，variable leaf water-milfoil）。一旦定殖成功，异叶狐尾藻会形成茂密的种群斑块，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。此外，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周边的游泳、划船、垂钓活动以及地产价值均造成负面影响。 1965年，新罕布什尔州温尼佩绍基湖的莫尔顿伯勒湾成为该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与中西部地区，在这些区域内，较高碱性的水域似乎会抑制该植物的生长。然而在其原生分布范围之外，该植物能够很好地适应与莫尔顿伯勒湾类似的、相对酸性、低碱度且营养匮乏的贫营养湖泊及海湾环境。 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（存在情况与种群密度）开展了调查。本次研究采用地球物理探测系统与常规水质测量手段，对可能为异叶狐尾藻定殖与生长提供适宜生境的湖底环境进行了识别。本研究成果旨在为联邦与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区域的方法。最终，这些信息可助力实现早期监测预警、入侵预防以及更高效的防控策略制定。 本次野外调查航次的作业信息可通过美国地质调查局海岸与海洋地质科学数据系统（U.S. Geological Survey Coastal and Marine Geoscience Data System）在线获取，链接为：https://cmgds.marine.usgs.gov/fan_info.php?fa=2005-004-FA。