Artificial nesting habitats as a conservation strategy for turtle populations experiencing global change

Area of Science:

• Herpetology
• Ecology
• Conservation Biology

Background:

• Diamondback terrapins (Malaclemys terrapin) face habitat loss in North American estuaries due to anthropogenic impacts.
• Degraded nesting sites and shading by invasive plants negatively affect terrapin embryo development and survival.
• Artificial nesting islands made from dredged sediments are a potential, yet unproven, habitat solution.

Purpose of the Study:

• To evaluate the impact of dredged soil and shading on diamondback terrapin hatching success.
• To determine if dredged bottom sediments can be utilized to increase available nesting habitats.
• To assess the suitability of aged dredge soil as a nesting substrate.

Main Methods:

• Field experiments were conducted in Barnegat Bay, New Jersey, comparing hatching success in natural loamy-sand versus dredged soil.
• Nests were monitored under both shaded and unshaded conditions over two years.
• Hatching success rates were recorded for diamondback terrapin (Malaclemys terrapin) nests in different substrate and light conditions.

Main Results:

• In the first year, natural loamy-sand yielded the highest hatching success (55.2%), with no hatchlings from fresh dredge soil.
• In the second year, unshaded loamy-sand had 85.3% hatching success, while 1-year-aged dredge soil achieved 59.4%.
• Aging dredge soil for one year significantly improved its suitability as an incubation substrate, likely due to salt washout.

Conclusions:

• Uncontaminated dredged soil, aged for at least one year, can serve as a suitable nesting substrate for diamondback terrapins.
• Constructing artificial islands using aged dredge soil may expand nesting opportunities and offer protection from predators.
• Habitat restoration using aged dredge soil presents a promising strategy for diamondback terrapin conservation in degraded estuarine environments.