Appendix E
Spotted Turtle Habitat Suitability Analysis
Final Report: Spotted Turtle (Clemmys guttata)
Habitat Assessment at Mentor Marsh, Lake
Co., Ohio (Sewer Line Replacement Project)
Prepared for:
Neal Hess
CT Consultants Inc.
3875 Embassy Parkway Suite 200
Akron, Ohio 44333
Prepared by:
Jeffrey G. Davis
625 Crescent Road
Hamilton, Ohio 45013
513-470-8748
[email protected]
October 12, 2015
1.0 INTRODUCTION
1.1 Purpose
This document serves to report the findings of a habitat survey, by an ODNR approved
herpetologist, for determining the suitability of habitat features and/or attributes for the
Ohio state threatened Spotted Turtle (Clemmys guttata; Figure 1) along the right of way
for a sewer line replacement project through Mentor Marsh in Lake County, Ohio
(Figure 2). The survey was recommended by the Ohio Division of Wildlife.
1.2 Site Description
The sewer line to be replaced is a segment that crosses Mentor Marsh in Lake County,
Mentor Township, Ohio from near the dead end of Woodridge Road on the north side of
the marsh near 41.73030°N -81.32198°W to the sewage treatment plant at
approximately 41.72357°N -81.33494°W. It extends southwest across the marsh to a
narrow channel of shallow, open water at approximately 41.72738°N -81.326332°W
over which the new sewer line will be bridged. The smell of the water at this point
suggested that sewage has leaked from the pipeline into the marsh. From this point the
proposed sewer line continues southwest through a woodlot to the sewage treatment
plant (Figure 3).
The portion of the marsh intersected by the pipeline is dominated by
the invasive phragmites or common reed (Phragmites australis). The existing pipeline
crosses the marsh in a sanitary causeway that has subsided in some places such that
the top of the sewer line is exposed at the surface (Figure 4). In areas where remnants
of the causeway exist there are tree species that are tolerant of hydric soils. Most
prevalent among them are cottonwoods (Populus deltoides), willows (Salix sp.) and
silver maples (Acer saccharinum). The phragmites grows in a dense monoculture in the
lower portions of the marsh, creating a nearly impenetrable tangle of vegetation and a
canopy that prevents sunlight from reaching the ground (Figure 5). Open water along
Wake Robin Trail is more than 300 feet east of the existing and proposed sewer lines.
The proposed sewer line will be installed adjacent to the existing one. The latter will be
decommissioned but not removed upon installation of the former.
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1.3 Spotted Turtle Natural History
The spotted turtle is a small freshwater turtle that inhabits shallow wetlands in the East
Coast-Great Lakes Region. Their habitats are usually clean shallow water with a mud
bottom and ample aquatic and emergent vegetation (i.e. bogs, fens, wet prairies, vernal
pools, and even roadside ditches). These wetlands must have an open canopy that
allows the turtles to bask in full sun. They become active very early in the spring and
can be visually seen basking on logs or emergent clumps of grass and sedges. When
disturbed they will take to the water and bury themselves in the mud. These turtles are
also quite terrestrial. Research has suggested over 60% of their time is found in upland
areas.
Mating and egg laying usually occurs from March to May depending on temperatures.
During the hot summer months, spotted turtles go into aestivation (a time of inactivity),
burying themselves in muskrats burrows or leaf litter. During the fall months there is a
short period of activity before they return to their hibernacula. Overwintering occurs in
muskrat burrows or in the soft mud at the bottom of the wetlands they inhabit.
2.0 METHODS
2.1
Desktop Survey
An initial examination of aerial photos was used to identify potential Spotted Turtle
habitat, specifically, open canopy emergent wetlands. Museum and literature searches
were conducted to determine the history of spotted turtle distribution in Lake County.
2.2 Site Visit
Because the segment of the sewer line to be replaced covers a distance of only about
0.8 miles, a site visit was scheduled on October 9, 2015 so the entire area to be
impacted could examined by a pedestrian survey. During the site visit, a search for
vegetation typical of spotted turtle habitat was undertaken. Among the plant species
associated with the spotted turtle habitat are arrowhead (Sagittaria latifolia), coontail
(Ceratophyllum demersum), sedges (Carex sp.), willows (Salix sp.), dogwoods (Cornus
sp.), and buttonbush (Cephalanthus occidentalis).
The canopy was evaluated to
determine if it was sufficiently open to allow spotted turtles access to sunlight for
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basking, and the substrate was examined to determine if it was soft enough to allow
them to burrow into it.
3.0 RESULTS
3.1 Literature Search and Museum Records
3.1.1 The literature search resulted in only one record. Conant (1938) reported a
single specimen (TZS 541) that was placed in the herpetological collection of the Toledo
Zoological Society. It was collected from the west end of Mentor Marsh. Conant (1951)
did not report any additional Lake County specimens.
Wynn and Moody (2006)
indicated a record for Lake County from prior to 1951 and it is likely the same specimen
reported by Conant (1938). They did not add any records to those discussed in earlier
publications.
3.1.2 The museum search resulted in one record in the American Museum of Natural
History (AMNH R-120799) collected in Lake County in 1931. The Toledo Zoological
Society collection was donated to the American Museum of Natural History about 15
years ago. It is very likely that AMNH R-120799 is the same specimen as TZS 541 and
if that is the case, no spotted turtles have been collected from Lake County, and more
specifically Mentor Marsh, in more than 80 years.
3.2
Site Visit (Pedestrian Survey)
The phragmites was so dense in the marsh that it created a canopy that would exclude
basking sites for spotted turtles. Therefore there was no suitable spotted turtle habitat
in the portion of the marsh intersected by the existing and proposed sewer line. There
was evidence of some ephemeral wetlands southwest of the marsh where the existing
and proposed sewer lines leave the marsh and continue under the closed canopy of a
woodlot.
The closed canopy make the habitat unsuitable for spotted turtles.
The
phragmites in the marsh grows so densely that the root mass would likely be
impenetrable to spotted turtles attempting to burrow into the mud. The smell of sewage
in the water suggests that it is not the cool, clean water the species typically inhabits.
4.0 RECOMMENDATIONS
Despite the fact that there is a historical record for spotted turtles at Mentor Marsh, the
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segment through which the current sewer line exists and the replacement sewer line is
proposed do not provide suitable habitat for the species at this time.
No further
consideration is necessary regarding spotted turtles along the proposed sewer
line right of way at Mentor Marsh. This recommendation is not valid if the proposed
route of the new sewer line installation moves outside of the proposed right of way.
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Literature Cited
Conant, R. 1938. The Reptiles of Ohio. The reptiles of Ohio. The American Midland
Naturalist 20(1): 1-200.
Conant, R. 1951. The Reptiles of Ohio (2nd ed.). Notre Dame. 284 p.
Wynn, D.E. and S.M. Moody. 2006. Ohio Turtle, Lizard, and Snake Atlas. Ohio
Biological Survey Miscellaneous Contributions Number 10. iv + 81 pp.
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Figures
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Figure 1. A spotted turtle from Green County, Ohio.
Figure 2. The sewer line extends southwest from near the dead end of Woodridge Road to the
sewage treatment plant in the lower left corner of the photo (3). The sewer line passes through
a monoculture of Phragmites between sites 1 and 2. At site 2 there was shallow water that
appeared to flow toward the west. Between sites 2 and 3, the sewer line is routed through a
woodlot with a closed canopy. The red line representing the sewer line right of way is
approximate.
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Figure 3. Between sites 2 and 3 (see Figure 2) the pipeline extends southwest along the edge
of a woodlot. The canopy created by the trees renders it unsuitable for spotted turtles.
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Figure 4. The existing sewer line is exposed at the surface in some areas where it crosses the
marsh. The water at this point (site 2 in Figure 2) smelled of sewage suggesting the water is
probably not the clean, cool water preferred by spotted turtles.
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