Distribution of the Pacific stingray (Styracura pacifica) in the Térraba River Mouth, Térraba Sierpe National Wetland, Pacific of Costa Rica

Coastal wetlands are vital habitats for elasmobranchs, yet the spatial ecology of many species remains poorly understood, hindering effective conservation. The Pacific chupare ray, Styracura pacifica , listed as Vulnerable by the IUCN, is one such data-poor species with virtually unknown feeding habits and limited ecological data. This study aimed to address the spatial ecology of S. pacifica within the Térraba-Sierpe National Wetland (HNTS), Costa Rica, providing baseline data for management. We employed a participatory science framework, integrating Local Ecological Knowledge (LEK) from artisanal fishers with over 15 years of experience in the area, to identify key sampling sites in the main river channel and intertidal sand flat pools. Data were collected between 2022 and 2023 using floating longlines and modified cast nets. For each captured ray, sex and disc width (DW) were recorded, alongside environmental variables like temperature and precipitation. Due to non-normal catch per unit effort (CPUE) distributions, non-parametric analyses were applied. Relationships between CPUE, disc width (DW), and environmental variables were assessed using Spearman correlations, and differences between ecosystems, years, and groups were evaluated using a rank-based test. A total of 66 individuals were captured across both habitats. Captures were exclusively composed of immature individuals, with significantly smaller DWs recorded in intertidal pools (19.6–37 cm DW) compared to the main channel (31-55.7 cm DW), confirming strong size-based habitat segregation. CPUE was significantly and inversely correlated with temperature in the main channel and with rainfall in the intertidal pools, suggesting dynamic shifts in distribution linked to local environmental conditions. Our findings provide empirical evidence that the HNTS functions as a crucial nursery system for juvenile S. pacifica. The observed sensitivity to temperature and rainfall highlights the vulnerability of these life stages to climate-driven habitat instability. Methodologies that allow us to track individuals and their movements, adapted to small-sized rays, are recommended for a better understanding of habitat use.