Download RARE, THREATENED, AND ENDANGERED SPECIES

PPRP Exhibit __ (STG-4)
Wildlife and RTE Species Exhibit
PSC Case No. 9290
Delmarva Power & Light Company – Church Substation to Maryland/Delaware State Line
138-kV Transmission Line Rebuild Project
RARE, THREATENED, AND ENDANGERED (RTE) SPECIES
Delmarva Power & Light Company (Delmarva Power) evaluated the proposed Church to
Townsend project ROW (Project) as potential habitat to both federal and state listed species.
Delmarva Power reviewed readily accessible information on the distribution of RTE species,
consulted with federal and state resource projection agencies, USFWS and DNR's Wildlife and
Heritage Service (WHS), and conducted field studies to document species presence/absence.
Coordination with WHS
WHS provided an environmental review of the Church to Townsend ROW for its entire length,
which was later supplemented by a DNR wildlife ecologist. In a letter dated February 24, 2011
(Appendix A), WHS determined that the Project route encroaches upon wetlands known to
support three state-listed plant species: state-endangered Harper’s fimbristylis (Fimbristylis
perpusilla) and featherfoil (Hottonia inflata), and state-threatened lowland loosestrife
(Lysimachia hybrida). The wetlands, also known as Delmarva bays, are within the Millington
Wildlife Management Area, and are designated as Nontidal Wetlands of Special State Concern
(NTWSSC1). An upland buffer of 100 feet surrounding a NTWSSC is regulated by MDE, which
may require permitting. Also in this area, WHS noted that the Project route crosses through a
wetland known to support the state-endangered eastern tiger salamander (Ambystoma tigrinum
tigrinum). Farther south, where the Project route crosses the Chester River at Millington, WHS
has records for eastern lampmussel (Lampsilis radiata) in the river, a species considered
possibly rare and currently given a state rank of uncertain for reasons such as lack of historical
records, low search effort, or cryptic nature of the species.
In a letter dated April 29, 2011 (Appendix B), a DNR wildlife biologist provided supplemental
environmental review following field visits to the Project site on March 14 and April 4, 2011. The
site visits confirmed breeding by tiger salamanders in two seasonal pools within the ROW, and
documented one of the highest numbers of egg mass counts in recent years at a seasonal pool
1
Nontidal wetlands of Special State Concern are the best examples of Maryland's nontidal wetland habitats and are designated
for special protection under the State's nontidal wetlands regulations.
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DELMARVA POWER-CHURCH TO DELAWARE STATE LINE-PSC CASE 9290
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adjacent to the ROW. Also on one site visit, potential habitat for state-threatened bog turtle
(Glyptemys muhlenbergii) was described in an area of scrub-shrub/emergent wetland within the
Cypress Branch floodplain and an emergent wetland in the floodplain of an unnamed tributary to
Cypress Branch. In a letter data July 1, 2011 (Appendix B), it was also noted that stateendangered barking treefrog (Hyla gratiosa) may be present in seasonal pools such as
Delmarva bays, and recommended field surveys for calling frogs and dipnet surveys for larvae.
Field Surveys
In response to information gained through agency coordination, Delmarva Power conducted
targeted field surveys of RTE species to determine presence within the ROW. Surveys for RTE
plant species in Maryland did not confirm the presence of any of the three species identified by
WHS (only one species – Carolina anglepod (Matelea carolinensis) – was confirmed in
Delaware near the state-line border). As indicated above, surveys for eastern tiger salamander
confirmed the presence of breeding salamanders in two pools within the ROW, and a pool with
very high breeding activity adjacent to the ROW. Surveys for barking treefrog were inconclusive;
no calling frogs were heard and dipnet surveys of seasonal pools did not yield any larvae.
Eastern Tiger Salamander (Ambystoma tigrinum tigrinum)
Eastern tiger salamander is a state-endangered species known from isolated breeding
populations along the Coastal Plain in Maryland (White and White 2002). The salamander
formerly had broader distribution on both Eastern and Western Shores, but populations have
declined in recent years owing to wetland loss, deforestation, water pollution, and vegetation
succession in breeding ponds (Smith 2009). For most of the year, the salamanders live
underground in deciduous or mixed woodland habitats, often with sandy substrates (White and
White 2002). Beginning in November, adult salamanders migrate to seasonal breeding pools
that form during the wetter winter season. Breeding occurs over the winter months and can
extend as late as mid-March, after which the adult salamanders return to upland forest habitats.
Egg masses deposited by female salamanders in pools hatch into larvae after about a month.
Larval salamanders develop over the ensuing weeks and metamorphosis generally occurs from
mid-June to late August, after which the juvenile salamanders disperse into upland forest
habitats.
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DELMARVA POWER-CHURCH TO DELAWARE STATE LINE-PSC CASE 9290
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In a letter dated April 29, 2012 (see Appendix B), MD DNR provided recommendations for
protecting eastern tiger salamanders in the vicinity of the wetland seasonal pools confirmed as
breeding habitat for this species, specifically:
1) to minimize the area covered and time that heavy equipment is in the vicinity (500 feet)
of these wetlands to avoid destroying burrows and salamanders; and
2) if possible, to conduct activities in these areas outside of the tiger salamander breeding
season (November to April).
In its ERD (Section 4.8.4, p 145), Delmarva Power has committed to restrict the timing of
construction for this section of the Project (between existing structures 265 and 269) to the
interval between August 2013 and October 2013. Project construction limited to this time
interval should protect not only the breeding adult population but also emergent juvenile
salamanders. No construction activities will occur within 500 feet of the breeding area waters
except during this period, and there will be no construction within the breeding pond areas
themselves. Delmarva Power should abide by this commitment but also, as MD DNR
recommends, minimize time spent within 500 feet of these habitats. Furthermore, these
restrictions should not only be implemented during construction, but also in ensuing years as
vegetation management is conducted. Vegetation management in these areas should be kept to
a minimum with respect to frequency and effort; physical methods of vegetation control should
be employed with no herbicide treatments within 500 feet of known salamander breeding
habitat.
Barking Treefrog (Hyla gratiosa)
Barking treefrog is a state-endangered species identified by DNR as potentially occurring along
the Project ROW. This species inhabits moist woodlands where it is usually found in trees and
shrubs, but also breeds in seasonal pools from late April through July (White and White 2002).
Targeted surveys conducted by Delmarva Power did not confirm the presence of this species
along the ROW corridor. If present, barking treefrogs would likely use the same breeding
habitats as the tiger salamander above, e.g. seasonal pools, Delmarva bays. Therefore, time of
year restrictions instituted for the tiger salamander would likely be protective of barking treefrogs
should they occur in these areas. If in the future barking treefrogs are determined to be present
along the ROW, protective measures would include time of year restriction from April to July on
vegetation management within 500 feet of breeding pools.
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Rare Plants
Three rare plant species known to occur in the vicinity of the Project at Millington Wildlife
Management Area are plants of wetland habitats. Both featherfoil and lowland loosestrife are
obligate species occurring only in wetland habitats, whereas Harper’s fimbristylis has a wetland
indicator status of Facultative Wetland+, indicating that it almost always occurs in wetland
habitats. Targeted field surveys conducted by Delmarva Power did not confirm the presence of
any of these species within the ROW. If in the future, any of these species are determined to be
present within the ROW; protective measures would include minimizing vegetation management
within and around wetlands where they occur and restricting any use of herbicides.
Ospreys
Osprey is a migratory bird of prey species that breeds annually in the Chesapeake Bay region.
Breeding birds return from their South American winter range as early as late February, but
most are present by mid-March (Ellison 2010). Mated pairs construct nests near open water and
frequently make use of made-made structures including duck blinds, marine navigation channel
markers, and transmission line towers. Female ospreys typically lay their eggs in April, usually
three, which are incubated by her for 35-37 days; however egg-laying dates in Maryland range
widely from 26 March to 20 July (Ellison 2010). Eggs hatch yielding nestlings that remain in the
nest for approximately 8 weeks. Most young are capable of sustained flight by late June or early
July; yet, after fledging from the nest, the young remain dependent on the parents for up to 2
months. Following the breeding season, ospreys begin leaving the region by late August and
most birds have departed by October (Ellison 2010).
Delmarva Power conducted a raptor nest survey along the Townsend to Church ROW to
determine nesting use of transmission line structures by species such as osprey. The survey
was conducted during spring and early summer 2011 and documented nesting ospreys on
existing 138 kV H‐frame pole structures and adjacent 230 kV lattice towers within the ROW.
One active osprey nest was confirmed on an existing H-frame structure in the vicinity of an
agricultural pond associated with the headwaters of Jacobs Creek. A total of 15 active osprey
nests and two non-raptor partial nests were observed on adjacent lattice towers. The nests were
located on lattice towers situated near agricultural ponds and major watershed drainages
including the Sassafras River, Herring Branch, Jacobs Creek, Cypress Branch, Mill Pond, and
Andover Branch.
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Although ospreys receive Federal protection under the Migratory Bird Treaty Act (MBTA),
removal of their nests outside of the breeding season is permitted by the USFWS. Delmarva
Power has indicated that it would remove the osprey nest on the H-frame structure as part of
the line reconstruction outside of the breeding season. With respect to the 15 osprey nests and
two non-raptor nests constructed on the 230 kV lattice towers, Delmarva Power has committed
(ERD, Section 4.6.3, p. 130) to implementing time-of-year restriction on construction activities
near these nests to avoid disturbance. For the protection of nesting ospreys, the time-of-year
restriction should span from mid-March through June. Earlier in the season is more critical than
later when mated pairs are establishing the nest and incubating eggs.
References
Ellison, W.G. 2010. Osprey (Pandion haliaetus). Pages 100-101 in 2nd Atlas of the Breeding
Birds of Maryland and the District of Columbia, ed. W.G. Ellison. The Johns Hopkins University
Press, Baltimore
Smith, S.A. 2009. Tiger salamanders – A living litmus test. The Maryland Natural Resource,
Spring 2009, pp. 20-23.
White, J.F. and A.W. White. 2002. Amphibians and Reptiles of Delmarva. Tidewater Publishers,
Centreville, Maryland. 248 pp.
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Appendix A – Wildlife and Heritage Service Letter
Appendix B – DNR Wildlife Ecologist Letters