JPEG images of bottom samples collected by the U.S. Geological Survey in Moultonborough Bay, Lake Winnipesaukee, New Hampshire in 2005 (JPEG Images)

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，危害最为突出的水生入侵植物为异叶狐尾藻（Myriophyllum heterophyllum，variable leaf water-milfoil）。该植物一旦定殖，便会形成密集的草床，改变水体的湖沼学特征，进而影响自然湖栖群落及其栖息生境。异叶狐尾藻的入侵还会干扰水体的休闲利用功能，对新罕布什尔州多座湖泊及周边池塘的游泳、划船、垂钓活动以及地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与中西部地区，在该原生分布区内，碱性较强的水体似乎会抑制该植物的生长。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及海湾中相对酸性、低碱度且营养匮乏的环境。

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）开展调查。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。该研究成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确定易受入侵区域的方法，以辅助其开展管理工作。最终，这些信息可助力实现早期监测、入侵预防以及更高效的防控治理策略。

本次科考航次的野外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）的在线平台获取，具体网址为https://cmgds.marine.usgs.gov/fan_info.php?fa=2005-004-FA。