Research trends on marine zooplankton in the southern Gulf of Mexico: A short review

The Gulf of Mexico (GoM) is a large interior sea located on the North American continent, which shares its waters with Cuba, the USA, and Mexico. Owing to its complex circulation pattern, high biological productivity levels, and bathymetry, the GoM is one of the 21 Large Marine Ecosystems in the American continent. Besides, along their coasts, numerous lagoons host a high species richness and serve as refuges, growth, and feeding areas for numerous species of high ecological and commercial value. The high biological productivity of the GoM and its adjacent areas is directly linked to the organisms positioned at the lowest levels of the trophic web, specifically the zooplankton. Studies of zooplankton communities in the northern GoM began in the early 20th century. In the Mexican portion, thanks to the Russian-Cuban expeditions in the 1960s, substantial progress was made in understanding the composition and distribution patterns of some zooplankton groups, which has increased considerably over the last two decades. This paper presents a short synthesis and review of the research trends on marine zooplankton in the southern GoM. Due to their significant numerical contribution and importance in commercial fishing, copepods and fish larvae are two of the most studied zooplankton groups to date. Decapods, rotifers, and doliolids have been largely neglected. Other groups have recently attracted attention due to the threats they face. For example, due to the acidification scenarios documented in the GoM, holoplanktonic mollusks, such as pteropods and heteropods, represent key groups. This review also discusses the threats to which zooplanktonic populations in the GoM are subject. Indeed, warming, acidification, and deoxygenation events, as well as plastic pollution, are aspects that should be considered in future research.