IMIS

Maps of the North Atlantic showing the average abundance of Metridia lucens during the a) Day and c) Night, and the abundance of Pleuromamma during the b) Day and d) Night from 1960-2019.

Some large zooplankton are known to conduct Diel Vertical Migrations (DVM), coming to the surface waters during the night to feed and avoid visual predators at depth during the daylight. The CPR survey consistently tows plankton recorders in the surface waters throughout night and day, and therefore has been able to detect DVM in zooplankton species that carry it out. These maps show the distribution of two large calanoid copepods, Pleuromamma spp. (multiple species are summed for this genus grouping) and Metridia lucens, recorded in the CPR survey during Day and Night across the North Atlantic, both species demonstrate DVM behaviour. M. lucens are found off the coast of Ireland and throughout the North Atlantic, while Pleuromamma are found in the lower latitudes of the North-western Atlantic.