Interannual Spatial Variability of the Western Hemisphere Warm Pool and the Impacts on Marine Protected Areas in the Mexican Pacific

The Western Hemisphere Warm Pool is the second warmest body of water on Earth and has been highlighted according to its significant influence on ocean and atmosphere components. This study focuses on the comparison of the interannual spatial variability of the Western Hemisphere Warm Pool in the Eastern Pacific (WHWP-EP) according to satellite-derived data from the Advanced Very High Resolution Radiometer. Secondly, the response of chlorophyll a (Chl-a) as a proxy of phytoplankton was evaluated for Marine Protected Areas (MPAs, which are considered the main tool for conservation of biological diversity) located in the Mexican Pacific with emphasis on anomalous events of the WHWP-EP. The response was predominantly negative, particularly in MPAs located in the Deep Mexican Pacific and southern Gulf of California, while the Midriff islands area (central Gulf of California) was not statistically significant due to the known higher resilience to warm events. Observed trends in the extension of the WHWP-EP and negative response of Chl-a in most of the MPAs highlight the need to consider phytoplankton in marine planning and management strategies, particularly in the area known as Deep Mexican Pacific, where MPAs has been reported with a lack of management effectiveness.