Using habitat suitability models to predict changes in seagrass distribution caused by water management practices

Habitat suitability (HS) models can help elucidate the relationship between organisms and their environment and simulate the potential impacts of human activities on species distributions. Here, we developed HS models for Thalassia testudinum and Halodule wrightii, two seagrasses found in Biscayne Bay (Florida, USA). These species are mostly found in nearshore habitats of the bay that are highly susceptible to changes in water quality because of their proximity to the city of Miami and activities and projects associated with the restoration of the Florida Everglades. The HS models parameterized with data collected at <900 sites highlighted salinity as a key factor determining habitat suitability for these seagrass species. Thalassia's suitable habitat was associated with higher, more stable salinity compared with that of Halodule, which was associated with lower salinity and shallower depths. Both species benefited under a simulated scenario of increased freshwater flow, but Halodule's suitable habitat increased by 71% compared with that of Thalassia's, which exhibited only an 18% increase. HS models such as those described here provide spatial modeling tools that can contribute science-based input into the management of coastal resources within an adaptive management framework.