Habitat suitability analysis for sea cucumber mariculture development in the coastal waters of Bangladesh

Sea cucumbers are bottom-feeding echinoderms that inhabit almost all marine environments, from the littoral to the hadal zones. They play an important role both ecologically and economically. We aimed to analyse the environmental drivers of sea cucumber habitats and to identify the suitable habitats for mariculture in the coastal marine waters of Bangladesh. We applied the generalized additive model (GAM) to evaluate the habitat suitability incorporating different ecological parameters along with the presence and absence data of sea cucumbers. Data were collected from various sources, including in-situ measurements, model simulations, and satellite observations. Our model revealed turbidity as the major ecological predictor for sea cucumber habitat suitability, followed by chlorophyll-a, surface eastward geostrophic seawater velocity current, sea surface temperature, the meridional component of the absolute geostrophic velocity current, salinity, DO, and depth. We found 9 km2 of area is suitable, 2 km2 is moderately suitable, 9 km2 is less suitable, and 90 km2 is not suitable for sea cucumbers. Our model had substantial agreement with in situ observation (AUC 0.91, R2 = 0.67, p < 0.002). As Bangladesh focuses on blue growth and emphasizes mariculture activities, our study will support the initiation of mariculture for non-conventional but commercially important items, such as sea cucumbers.