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Turtle Nesting Habitat Conservation

Written by: Breeka Li Goodlander

Turtles play an important role in maintaining the function and biodiversity of natural ecosystems. Turtles do this, namely by acting as significant bioturbators of soil (think small-scale tilling!), infaunal miners of [aquatic] floors,  nutrient re/cyclers, dispersers and germination enhancers of seeds, and [primary] consumers (Lovich et al., 2018). Did you know that turtle eggs are almost entirely protein and lipids (Booth, 2003)? This means that turtle eggs act as significant biomass producers for their environment. When these shells are consumed or broken down, nutrient transfer occurs and organisms flourish. In other words, turtle eggs help fertilize soil! 

On a broader scale, turtles maintain the function and biodiversity of ecosystems through mineral and nutrient cycling from aquatic to terrestrial ecosystems and vice versa. Turtles have even shown to have profound importance in the cleanup of polluted water bodies due to this cycling (Sinha, 1995). This means that even while turtles bask in the sun and take their time to cross the road, they are always on the clock and working for the natural environment. Unfortunately, of the 356 species of turtles worldwide, approximately 61% are threatened or endangered due to habitat destruction, climate change, and more (Lovich, et al., 2018). So how can we support these critters that do so much in light of our collective current situation? 

One solution is to create a designated turtle nesting habitat (TNH), which is exactly what the Franklin Conservation Department (FCD) is doing at the DelCarte Conservation Area (DelCarte). By following the Advisory Guidelines for Creating Turtle Nesting Habitat (NHESP, 2009), the FCD is hoping to increase the biodiversity of the local aquatic-terrestrial systems and preserve the function and diversity of DelCarte’s natural ecosystem. In doing so, this Project aims to ensure future protection and success of Massachusetts native turtle species and their ecological interactions with their surrounding environment. 

So what turtle species is the DelCarte TNH designed to support? The DelCarte TNH is designed to suit the nesting needs of the painted turtle (Crysemys picta) and common snapping turtle (Chelydra serpentina), both freshwater/estuary species. While not threatened or endangered, these species are still vulnerable to disturbance and impacts, and the installation of the TNH will help bolster their ability to persist and prosper well into the future.

The DelCarte TNH totals approximately 1,151 square feet and can be found at the beginning of the main trailhead, adjacent to the north pond. If one were to visit DelCarte now, they would notice a “grubbed” area and a split-rail fence in the shape of a square, with exposed substrate at its bottom. This square is the designated TNH and demarcates the area away from human influence, while still allowing ground clearance pondward for gravid turtles. While the TNH may look small – and it is! The nesting area itself is only 400 square feet of exposed substrate. – an additional 751 square feet of vegetation including, but not limited to, little bluestem (Schizachyrium scoparium), partridge pea (Chamaecrista fasciculata), sweet fern (Comptonia peregrina), and lowbush blueberry (Vaccinium angustifolium) will be planted around the fence to attract and provide cover for gravid females and hatchlings once they emerge from the nest. As a tip, any TNH substrate should consist of well-drained soil, sand or gravel for successful nesting. Ground vegetation should also be sparse and include native sedge, grasses, and a few low growing shrubs (less than 2 to 5 percent cover for the site) (NHESP, 2009). 

As of last autumn, the TNH was dominated by crushed gravel and weedy, aggressive, and sometimes invasive, upland vegetation such as, but not limited to, common mugwort (Artemisia vulgaris), strawcolored flatsedge (Cyperus strigosus), Virginia creeper (Parthenocissus quinquefolia), Canada goldenrod (Solidago canadensis), pigweed (Polygonum aviculare), common blackberry (Rubus allegheniensis), giant foxtail (Setaria faberi), Eastern black nightshade (Solanum ptychanthum), broad-leaved dock (Rumex obtusifolius), curly dock (Rumex crispus), and pale smartweed (Persicaria lapathifolia). Work has begun to remove all vegetation, except for strawcolored flatsedge, Canada goldenrod, and common blackberry, to the best extent practicable, and revegetate with little bluestem, partridge pea, sweet fern, lowbush blueberry, and other native plants fit for the surrounding environment. 

So where in the process is the project now? Currently, staff are working on sourcing proposed vegetation for planting later in May. Additionally, the TNH substrate will likely need to be scarred prior to May 1 (i.e., before nesting season). 

Future goals for the DelCarte TNH include the installation of educational signage demonstrating the importance of turtles, their nesting habitat, and why the TNH is “off limits”, and game cameras to monitor nesting success. The FCD has high hopes that the TNH can inspire others to be more mindful of their impacts to the natural world and install their own TNH per the Guidelines. Any nesting that occurs within the DelCarte TNH will be provided to the Massachusetts Natural Heritage and Endangered Species Program (NHESP) to provide support for the state-wide installation of designated Turtle Nesting Habitat. The TNH is part of a larger ecosystem restoration project, which can be followed here

 

References 

Booth, D.T. Composition and energy density of eggs from two species of freshwater turtle with twofold ranges in egg size. (2003) Comparative Biochemistry and Physiology Part A 134, 129-137 

Lovich, J.E., Ennen, J.R., Agha, M., & Whitfield Gibbons, J. Where Have All the Turtles Gone, and Why Does It Matter? (2018) BioScience, 68(10), 771-781. 

Natural Heritage and Endangered Species Program, Massachusetts Division of Fisheries and Wildlife. (2009) Advisory Guidelines for Creating Turtle Nesting Habitat. 1-4. 

Sinha, R.K. Commercial exploitation of freshwater turtle resource in the middle Ganges River System in India. (1995) Proceedings of the International Congress of Chelonian Conservation, 14-20.