At local to regional scales, tropicalisation often increases species richness where warm-water species extend their ranges to overlap with existing communities and decreases species richness where warming waters extirpate species  . Latitudinal estimates from catalogued observations show declining species richness in equatorial waters over the past 50 years, with concomitant increases in species richness at mid-latitudes; the pattern is especially prominent in free-swimming pelagic species . Similar patterns among marine animals have been described previously for historical warming events . Tropicalisation is associated with increased representation of herbivorous species , although observations and theory suggest that dietary generalism can also favour range-shifting species .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report