Abstract

The Caribbean Sea encompasses a vast range of physical environmental conditions that have a profound influence on the organisms that live there. Here we utilise satellite and in situ products to undertake a region-wide categorisation of the Physical Environments of the Caribbean Sea (PECS). The classification approach is hierarchical and focuses on physical constraints that drive many aspects of coastal ecology including species distributions, ecosystem function and disturbance. The first level represents physicochemical properties including metrics of sea surface temperature (average, minimum and maximum monthly mean), turbidity (relative frequency of anomalies), and salinity (average). The second level considers mechanical disturbance and includes both chronic disturbance from wave exposure and acute disturbance from hurricanes. The maps have a spatial resolution of 1 km2. An unsupervised neural network classification produced 16 physicochemical provinces for the Caribbean Sea. Spatial patterns in province geography reflect well-known ocean processes. The provinces can be categorised into six broad groups: (1) areas of high turbidity and low salinity, such as the Orinoco River plume; (2) areas of high turbidity, broadly distributed in the basin; (3) areas low salinity such as the high runoff region along Panama and Costa Rica; (4) upwelling areas in Yucatan and the southern Caribbean; (5) high-latitude areas including the waters of the Gulf of Mexico; (6) offshore waters of the inner Caribbean. Because physical environments underpin so much of coastal ecosystem structure and function, we anticipate that the PECS classification will facilitate comparative analyses and inform the stratification of studies across environmental provinces.