C r i t i c a l Issue Assessment & Control Addressed by 3 management objectives, 5 action plans The Piscataqua Region watershed is experiencing in the future. Both Maine and increased invasion by terrestrial, freshwater and have active programs to control the spread of marine exotic species. Humans through shipping, these species through volunteer lake monitoring trade, overland travel, and importation of non- and through the “Lake Host” program where native host species have introduced some of these volunteers check boats at landings and inform and animals, while others have migrated boaters about aquatic invasive plants. “Studies show that due to changes in habitat temperatures and storm invasives can reduce patterns. Many have the capacity to opportunisti- Invasive marine plants and animals include the natural diversity, cally and quickly invade disturbed habitats. Inva- Chinese mitten crab, green crab, Asian shore impact endangered sive species can be thought of as non-indigenous crab, tunicates, and disease causing parasites, such or threatened species that adversely affect the habitats they in- as MSX and Dermo. These invaders are harmful species, reduce vade economically, environmentally or ecologi- to shellfish, eelgrass habitats and the overall na- wildlife habitat, cally. For instance, research funded by PREP has tive biodiversity of estuarine and marine habitats. create water quality Research to evaluate the susceptibility of estuar- impacts, stress and documented significant native clam mortality ies to these invaders suggests that temperature reduce forest and from abundant populations of non-native green and salinity are important factors in survivability. agricultural crop crabs. Another example is the invasion of local production, damage marshes with the non-native invasive variety of Development of a marine invasive management personal property, common reed (Phragmites australis), which forms plan will highlight the most effective measures to and cause health dense monoculture stands that displace native minimize impacts on existing habitats. problems.” vegetation and reduce the quality of the habitat

- Gu i d e t o Inv a s i v e for most wildlife. Up l a n d Pl a n t Sp e c i e s in Ne w Ha m p s h i r e , 2005 The NH Coastal Watershed Invasive Part- nership (CWIPP) was formed to coordinate re- gional invasive plant management activities between federal and state agencies and land conservation organizations. Target invasive species include com- mon reed, purple loosestrife, bittersweet, buck- thorn, Japanese knotweed, burning bush, pepper- weed and Japanese bar ber r y. These plant s displace native species and can alter coastal habitats. Soil disturbance and road impacts aid the spread of these invasives, so the rapidly developing Pis- cataqua Region is particularly at risk.

At present, CWIPP includes all 42 New Hamp- shire communities in the Piscataqua Region wa- tershed. Several projects are underway in New Castle, Rye, and North Hampton and in the Crommett Creek watershed in Newmarket and Durham. The 10 watershed communities in Maine work with the Maine Department of Con- servation and the University of Maine Coopera- tive Extension on invasives control. Coordination of these programs across the full watershed area Program - NH Coastal Coletti C. would be valuable. Perennial pepperweed ( latifolium) is an aggressive non-native plant of the mustard family Common freshwater nuisance species are milfoil, that creates dense stands, out-competing native plant water chestnut, fanwort, and didymo (rock snot). species, and destroying habitat for many species of These organisms degrade lake, pond and river animals. Through its pepperweed patrol program, the habitats and affect aquatic recreation and fisher- NH Coastal Program has managed the small ies. Boaters that move from lake to lake can pepperweed population in New Hampshire through easily carry these plants from place to place. Ze- early detection surveys and control using targeted hebicide treatment and hand-pulling. bra mussels may pose a threat to rivers and lakes 18