Researchers can only monitor the population in a few places. So, the team—along with scientists from Havenworth Coastal Conservation and Florida International University—developed a new spatial model to predict where else sawfish may live. This helps identify potential habitats outside the survey area based on key environmental characteristics where they were sampled.
The research, “Predictive modeling of juvenile smalltooth sawfish habitats: challenges and opportunities for conservation” was published in the journal Ecology and Evolution on January 21, 2025.
Identifying Key Elements of Sawfish Habitat
To identify key habitat features influencing the occurrence of juvenile smalltooth sawfish, long-term sawfish abundance data in relation to environmental data was assessed from where they were found—including water and mangrove tree properties. Fortunately, long-term survey efforts have produced a large and valuable dataset of sawfish abundance and habitat traits. When a sawfish is encountered, researchers measure nearby environmental attributes, including:
- Mangrove canopy overhang
- Mangrove root density
- Water temperature
- Water salinity
- Water depth
- Bottom substrate

“Models can only perform as good as the data they’re fed,” said coauthor Simon Dedman of Florida International University. “We’re excited to learn key habitat features for this species and are optimistic that ongoing improvements in data sharing will make it easier to do these kinds of analyses, to make it easier to protect species faster.”
Predicting Sawfish Distribution
The results of spatial modeling were used to predict where else juvenile sawfish might live outside of the long-term sampling area. The predictions were based on areas with specific habitat features most strongly correlated with sawfish presence and abundance from the surveys.
After analyzing more than a decade of data, juvenile sawfish were found to rely heavily on very shallow, warm, saline waters fringed with dense mangrove roots.
Using these features, the model successfully predicted consistent sawfish presence beyond areas currently monitored. This includes additional areas within the Ten Thousand Islands National Wildlife Refuge and Everglades National Park. While there are many sample sites within the park, the model identified new places that have either never been sampled before or had minimal sampling efforts.
“We already know that Everglades National Park and Ten Thousand Islands National Wildlife Refuge serve as crucial nursery habitat for juvenile smalltooth sawfish, but our sampling efforts have limitations,” said Andrea Kroetz, lead author of the study. “The model provides additional evidence that juvenile sawfish are very likely present in other areas within this Critical Habitat that we haven’t been able to sample yet, which will guide us in future sampling and monitoring efforts for the species.”
The model domain covered one of the two existing Critical Habitat units that were designated in 2009 to promote juvenile recruitment to the adult population. It could not predict sawfish presence outside this area due to a lack of high-resolution coastal environmental data.
Now that researchers know what environmental characteristics are most important for juvenile smalltooth sawfish habitat, they know what data are needed to identify other important places. With higher resolution environmental data, this model can be a powerful tool to predict habitat for smalltooth sawfish beyond the sampling universe. It can also predict if sawfish habitat exists outside designated Critical Habitat units.
Healthy Habitats Support Recovery
The primary threats to smalltooth sawfish are habitat loss and bycatch in fisheries. Young sawfish rely on shallow estuarine habitats fringed with vegetation, especially red mangroves, as nursery areas. Coastal development in the Southeast United States has changed or destroyed much of this habitat. Continued development of these areas—in particular, the Charlotte Harbor Estuary Unit—threatens viable nursery habitats and could limit sawfish population growth.

These findings provide information that can be used to inform conservation actions to support sawfish recovery. As climate change continues to impact marine ecosystems, understanding the specific environmental preferences of threatened and endangered species becomes increasingly vital. Protecting mangrove habitats, especially in regions vulnerable to pressures such as coastal development and pollution, is critical for sawfish recovery. These habitats should be prioritized for protection and restoration.
The publication was led by Dr. Andrea Kroetz of Havenworth Coastal Conservation and included researchers from NOAA Fisheries and Florida International University.