Table 1 Covariates considered in density surface modeling.

From: Long-term random sampling confirms high-use areas and indicates declining abundance of juvenile smalltooth sawfish (Pristis pectinata) in Charlotte Harbor, Florida

Covariate

Description

Min_Depth

Minimum depth (m) in micro-grid, determined from BlueTopo bathymetry

Avg_DO

Mean dissolved oxygen (mg/L) value across samples on given survey date within a micro-grid

Avg_temp

Mean temperature (°C) across samples on given survey date within a micro-grid

Avg_salin

Mean salinity across samples on given survey date within a micro-grid

Avg_pH

Mean pH across samples on given survey date within a micro-grid

Min_MDTS

Minimum mangrove distance to shore (m)

Sum_MNN

Sum of mangrove nearest neighbor values from Zonal Statistics

Year

Year of sampling

Season

“Spring/Summer” (March–August) or “Fall/Winter,” based on month of sampling

River

River nearest sampling location (i.e., Caloosahatchee, Myakka, or Peace)

DistToRM

Distance from sampling location to nearest river mouth (m), with locations outside of river expressed as negative distances

DevelopedSL

Sampling grid exclusively contains developed shoreline (1) or contains some natural shoreline (0)