Changes in habitat availability for multiple life stages of diamondback terrapins (Malaclemys terrapin) in Chesapeake Bay in response to sea level rise

Global sea level rise (SLR) will significantly alter
coastal landscapes through inundation and erosion of lowlying
areas. Animals that display area fidelity and rely on
fringing coastal habitats during multiple life stages, such as
diamondback terrapins (Malaclemys terrapin Schoepff 1793),
are likely to be particularly vulnerable to SLR-induced changes.
We used a combination of empirical nest survey data and
results from a regional SLR model to explore the long-term
availability of known nesting locations and the modeled availability
of fringing coastal habitats under multiple SLR scenarios
for diamondback terrapin in the MD portion of
Chesapeake Bay and the MD coastal bays. All SLR scenarios
projected the rapid inundation of historically used nesting locations
of diamondback terrapins with 25%–55% loss within
the next 10 years and over 80% loss by the end of the century.
Model trajectories of habitat losses or gains depended on habitat
type and location. A key foraging habitat, brackish marsh,
was projected to decline 6%–94%, with projections varying
spatially and among scenarios. Despite predicted losses of
extant beach habitats, future gains in beach habitat due to
erosion and overwash were projected to reach 40%–600%.
These results demonstrate the potential vulnerability of diamondback terrapins to SLR in Chesapeake Bay and underscore
the possibility of compounding negative effects of SLR
on animals whose habitat requirements differ among life
stages. More broadly, this study highlights the vulnerability
of species dependent on fringing coastal habitats and emphasizes
the need for a long-term perspective for coastal development
in the face of SLR.