Abstract:
Biological and environmental conditions are drivers of fish habitat use, making it
essential to understand how fish move and use specific areas to inform effective fisheries manage-
ment and conservation. This study quantified the residency and habitat use patterns of the juve-
niles and early adults of 2 commercially exploited snappers (Lutjanidae) in Santa Elena Bay, a trop-
ical estuarine embayment influenced by a seasonal upwelling in the north Pacific coast of Costa
Rica. Using an array of 28 acoustic receivers, we monitored 14 Colorado Lutjanus colorado (28.8–
48.9 cm) and 16 Pacific dog L. novemfasciatus (22.5–49.3 cm) snappers over 22 mo. Both species
were detected inside the bay over 60% of the monitoring days, showing higher relative abundance
in mangrove and transitional estuarine habitats. Throughout the study, a shift in habitat use was
observed for both species. Individuals moved from mangrove and transitional habitats to the outer
reef habitat and exhibited a decreasing occurrence probability over time, suggesting they leave the
bay as they mature. Season and environmental variables, e.g. temperature, had minimal or no effect
on the occurrence of the tracked snappers in the bay. However, roaming varied seasonally, increas-
ing during upwelling periods. These results suggest that habitat connectivity facilitates gradual life
stage transitions, indicating that Santa Elena Bay likely supports essential fish habitat for commer-
cially important species, particularly for L. novemfasciatus. Results also highlight the importance
of integrating knowledge of the complex interplay of biological components (e.g. developmental
and intra- and interspecific interactions) and seasonal habitat dynamics into conservation and
management strategie
