Biodiversity Studies • Wetland Delineation & Assessment • Habitat Management • GIS Mapping • Permitting Vernal Pool Survey Results 1717, 1733, 1753 Storrs Road Mansfield, CT Submitted to: Robert Moskowitz Submitted by: Eric Davison Wildlife Biologist Registered Soil Scientist Certified Professional Wetland Scientist Date: 12-24-19 Davison Environmental, LLC • 10 Maple Street, Chester, CT 06412 • 860-836-6576 • www.davisonenvironmental.com CONTENTS 1.0 INTRODUCTION ............................................................................................................ 1 2.0 VERNAL POOLS DEFINED ........................................................................................... 1 3.0 TERRESTRIAL (NON-BREEDING) HABITAT ................................................................ 2 4.0 SURVEY METHODS ...................................................................................................... 2 5.0 SURVEY RESULTS ....................................................................................................... 3 5.1 Wetland Characteristics .............................................................................................. 3 5.2 Vernal Pool Survey Results & Wildlife Observed ........................................................ 3 6.0 REFERENCES ............................................................................................................... 5 ATTACHMENTS • Figures 1-2 • Site Photographs Vernal Pool Assessment Storrs Road, Mansfield, Connecticut 1.0 INTRODUCTION Davison Environmental, LLC conducted a vernal pool assessment within wetlands on three contiguous parcels located on the south side of Storrs Road in Mansfield (the “site” hereinafter). See attached Figures 1 and 2 which illustrate the location of the site. These parcels total +25 acres, with one large contiguous wetland system covering a large portion of the properties. Davison Environmental was originally retained to delineate the wetlands and watercourses on the site, which was completed in January of 2019. A survey of the delineated wetland boundary was provided by Bohler Engineering and that data was digitized using a Geographic Information System (GIS) software georeferencing tool and plotted onto Figure 2 in order to illustrate the approximate location and extent of the wetlands that were studied on the site. 2.0 VERNAL POOLS DEFINED Vernal pools are ephemeral waterbodies that provide critical breeding habitat for woodland amphibians, particularly mole salamanders (Ambystoma spp.) and wood frog (Lithobates sylvaticus). Many vernal pool definitions have been developed by both regulatory agencies as well as conservation organizations. While these definitions vary slightly, they all include the same common critical characteristics. In the Northeastern U.S., a recognized source regarding protection of vernal pools is a document developed by Calhoun and Klemens (2002), entitled: Best development practices: Conserving pool-breeding amphibians in residential and commercial developments in the northeastern United States (the “BDP Manual”, herinafter). The BDP Manual provides the following operational definition of vernal pools: “Vernal pools are seasonal bodies of water that attain maximum depths in the spring or fall, and lack permanent surface water connections with other wetlands or water bodies. Pools fill with snowmelt or runoff in the spring, although some may be fed primarily by groundwater sources. The duration of surface flooding, known as hydroperiod, caries depending upon the pool and the year; vernal pool hydroperiods range along a continuum from less than 30 days to more than one year. Pools are generally small in size (<2 acres), with the extent of vegetation varying widely. They lack established fish populations, usually as a result of periodic drying, and support communities dominated by animals adapted to living in temporary, fishless pools. In the region, they provide essential breeding habitat for one or more wildlife species including Ambystomid 1 | Page Vernal Pool Assessment Storrs Road, Mansfield, Connecticut salamanders (Ambystoma spp., called “mole salamanders” because they live in burrows), wood frogs (Rana sylvatica), and fairy shrimp (Eubranchipus spp.).” Most vernal pool indicator species enter pools to breed in the late winter or early spring (March- April), with juvenile dispersal from pools occurring from June – October. The exception to this is the marbled salamander which breeds in pools in late summer and early fall (August- September), with juvenile dispersal occurring from May – July. 3.0 TERRESTRIAL (NON-BREEDING) HABITAT Vernal pool wildlife utilize upland (non-wetland) forested habitat adjacent to vernal pools (Colburn, 2004). The forest provides terrestrial non-breeding habitat for amphibians, where they feed on the forest floor and shelter beneath surficial cover objects (e.g., rocks, logs) and within fossorial small mammal burrows. Forests not only provide habitat, but the trees adjacent to vernal pools are critical to vernal pool ecology, as they contribute to the food web (via detritus inputs), help maintain cool water temperatures, and affect pool hydrology (Colburn, 2004). Vernal pool amphibians disperse a significant distance into forests surrounding vernal pools. A number of studies have documented dispersal distances of indicator species (Colburn 2004, Windmiller 1996, Semlitsch 1998). Individuals commonly migrate 400-800 meters or more from uplands to their breeding pool (Colburn 2004). 4.0 SURVEY METHODS Site visits were conducted on April 16th and May 10th, 2019. The purpose of those visits was to search site wetlands for larval and adult amphibians in areas of shallow water. This work was timed appropriate to record the early spring breeding activity of vernal pool wildlife. Aquatic and semi-aquatic species were also catalogued. On both site visits two biologists waded through site wetlands and visually surveyed for egg masses, used dipnets to search for larval and adult amphibians within the water column, and cover searched the wetland-upland interface to look for amphibians under cover objects (rocks, logs and other surficial material). On the May 10th survey, two biologists utilized a seine net and dipnets to capture and inventory species located in the deeper portions of the pond and surrounding marsh habitats. During both surveys, any amphibians heard chorusing were also noted. 2 | Page Vernal Pool Assessment Storrs Road, Mansfield, Connecticut 5.0 SURVEY RESULTS 5.1 Wetland Characteristics Two wetlands occur on the site. The primary wetland, which occupies a large portion of the survey area, forms the headwaters to Cedar Swamp Brook. The system is part of the Willimantic River sub regional drainage basin. This wetland includes a pond (totaling ca. 1.5 acres) and bordering marsh with a narrow fringing shrub swamp. The northeastern and southwestern portions of this wetland are forested. These cover types are noted on Figure 2. Wetland hydrology varies across the wetland in response to the variable topography but consists predominately of permanently ponded wetlands. This hydrology has been enhanced and maintained by beaver, as there is an active beaver dam located at the southwest side of the wetland. The western portions of the wetland consist of open water (i.e., pond), while the shallower fringes along the eastern side are densely vegetated. Areas of dense submergent aquatic and emergent vegetation are present within the open marsh portions of the wetland. The southeastern, northeastern and northwestern portions of the wetland are forested. The hydrology in these forested areas is largely saturated to temporarily flooded. The wetland drains in a southwesterly direction (into Cedar Swamp Brook). A second small wetland (field demarcated by wetland flag #42-53) straddles the southern site boundary near Professional Park Road. This wetland is a small gently sloped forested wetland with a saturated hydrology. The wetland does not contain areas of prolonged standing (or flowing) water and therefore offers little habitat for wetland-dependent wildlife. It is not a vernal pool. 5.2 Vernal Pool Survey Results & Wildlife Observed Wetland-dependent and wetland-associated wildlife observed during the survey work are listed below in Table 1: Table 1: species observed Common Name Scientific Name Spring peeper Psuedacris crucifer Green frog Rana clamitans Bullfrog Rana catesbeiana Wood frog Lithobates sylvaticus Pickerel frog Rana palustris Gray treefrog Hyla versicolor Redback salamander Plethodon cinereus Red-spotted newt Notopthalmus viridescens 3 | Page Vernal Pool Assessment Storrs Road, Mansfield, Connecticut Table 1 continued… Garter snake Thamnophis sirtalis Painted turtle Chrysemys picta Fish Bluegill Lepomis macrochirus Pumpkinseed Lepomis gibbosus Chain pickerel Esox niger Golden shiner Notemigonus crysoleucas Minnows Birds Mallard Anas platyrhynchos Canada goose Branta canadensis Red-winged blackbird Agelaius phoeniceus Eastern kingbird Tyrannus tyrannus Tree swallow Tachycineta bicolor Barn swallow Hirundo rustica No vernal pools were found on the site. The wildlife assemblage present is dominated by limnetic species that inhabit open water. These species require permanent flooding, as opposed to seasonal flooding (i.e., along with seasonal drying) utilized by vernal pool species. The littoral zone, located on the fringes of the pond where the water is shallow and emergent and submergent vegetation occur, is occupied by species that favor marsh habitats