Full ecoregional plan - Conservation Gateway

The expert interviews provided critical information regarding the biological diversity andcondition of sites across the region. Although a standardized information form was used tocollect the 452 expert interview site records, the varying background of the interviewees led tovast differences in the level of detail recorded on the interview forms. Many fields were leftentirely blank on most interview forms, including in nearly all cases the ranking fields for size,condition, and landscape context. For example only 38 of the 452 had any landscape contextranks listed. The significant blanks in relation to some of these larger scale condition attributeshighlighted the inability of most interviewees and TNC staff to put the described sites into size,condition, or landscape rank categories given the available information. Ranking requireddetailed knowledge of the desired native natural biotic community vs. the current bioticcommunity, understanding of the current and natural flow regime, the ripairian and watershedcondition around site, and the ability to compare the site to the existing range of quality amongother sites over large spatial watershed scales. Despite these blanks, much useful information onlocal conditions and biological diversity was collected through this interview process. Theinformation on the presence of particular species, biological communities, substrate diversity,temperature, flow, and other key ecological processes at the sites was particularly helpfulbecause this information could not be gathered from GIS. In many cases information on exoticspecies and other local condition information such as dam management, bank stability, smallerlocal water withdrawals/well, and riparian buffer condition were noted.Although exotic species could not be comprehensively evaluated for each size 2 watershed,nonindigenous species are a significant threat to aquatic ecosystems in this analysis area.Nonindigenous species have a number of negative impacts such as competition with indigenousspecies for food and habitat, reduction of natives by predation, transmission of diseases orparasites, hybridization, and habitat alteration. The USGS Nonindigenous Aquatic Speciesdatabase (http://nas.er.usgs.gov) that records of all introduced, regardless of whether or not theybecause established, lists 94 introduced fish species in New England, with 25 of those speciesexotic to the region. The most widespread introduced fish species in New England include thebluntnose minnow, brown trout, burbot, cutlips minnow, fathead minnow, lake trout, largemouthbass, pearl dace, pumpkinseed, rainbow smelt, rainbow trout, rock bass, round-whitefish, andtrout-perch. In addition to fish, a large number of nonindigenous species of other taxa such asplants, amphibians, reptiles, mammals, mollusks, crustraceans, and sponges have also enteredaquatic systems and caused significant ecosystem alteration. For example in New England, theUSGS database referred to above reports 9 (7 exotic) amphibians, 1 exotic jellyfish, 8 (2 exotic)crustaceans, 1 exotic byozoan, 15 (10 exotic) mollusks, 17 (5 reptiles), 4 (1 exotic) tunicate, and23 aquatic vascular plants. Although these introductions have not all resulted in establishedpopulations, some of the most problematic and invasive species within the 5 EDUs include theasiatic clam, purple loosestrife, common reed grass, Eurasian water-milfoil, water-chestnut,yellow iris, curly pondweed, two-leaf water-milfoil, European water-clover, Carolina fanwort,watercress, Brazilian waterweed, dotted duckweed, pond water-starwort, and hydrilla. Thesespecies have or can significantly alter physical and biological functions of aquatic systems. Forexample, the water chestnut is a highly invasive species that can out-compete native plants,choke the waterbodies it invades, and reduce oxygen levels that increases the potential for fishkills. Similarly, Eurasian watermilfoil, a stringy submerged plant, can quickly proliferate andaggressively compete with native plant communities to form large dense mats that clogwaterbodies. Purple Loosestrife, an invasive wetland perennial plant, will grow densely inshallow waterbodies or wetlands and can eliminate food and shelter for wildlife includingREVISED 6/2003AQUA-RESULTS-35