Abstract

Designation of essential fish habitat requires a detailed understanding of how species-specific vital rates vary across habitats and biogeographical regions. This is especially true for species like the economically important brown shrimp (Farfantepenaeus aztecus) which occurs in multiple habitat types across a wide geographic range (southeastern US Atlantic and Gulf of Mexico (GoM) coasts) and exhibits variation in vital rates to small-scale variability in habitat conditions. As juveniles, brown shrimp occupy a suite of interconnected habitats within the estuarine mosaic before migrating offshore as adults. In the southeastern US, intertidal creeks make up a substantial proportion of available habitat within the estuarine mosaic, yet habitat-specific vital rates, including growth, are currently unavailable. We therefore sought to (1) estimate growth rates of juvenile brown shrimp in intertidal creek habitat within a high salinity, southeastern US estuary, the North Inlet estuary in South Carolina, and (2) compare our estimated rates with those from salt marsh habitats in northern GoM estuaries, the only other estuaries where field-derived estimates for juvenile brown shrimp are available. Juvenile brown shrimp collected over a 10-week period (May–July 2021) ranged from 25 to 95 mm TL and appeared to emigrate from the intertidal creek to deeper waters beginning at ~ 65 mm TL. Daily growth rates ranged from 0.45 to 2.30 mm day−1, with the highest rates estimated early in the study period. Despite differences in estimation method, salt marsh habitat type, and region, estimated growth rates from the North Inlet estuary were nearly identical to those from northern GoM estuaries. Collectively, our results suggest that despite differences in habitat geomorphology, spatial extent, and temporal availability, intertidal creeks may provide juvenile brown shrimp with similar nursery function to other habitats within the estuarine seascape.