NEW DELHI: A new study shows for the first time at a global scale and across all kinds of species that marine life has been changing its distribution away from the equator in direct response to climate change.
As predicted by climate warming, the number of species has decreased at the equator and increased in the sub-tropics since the 1950s.
This was the case across all 48,661 species, and when they were split into those living on the seabed (benthic) and in open water (pelagic), fish, molluscs and crustaceans.
The results from the University of Aucklandled research showed that pelagic species had shifted pole ward in the northern hemisphere more than benthic.
The lack of a similar shift in the southern hemisphere was because ocean warming has been greater in the northern than southern hemisphere.
Previously, the tropics were considered stable and an ideal temperature for life because so many species live there.
Now, scientists say that the tropics are not so stable and are increasingly too hot for many species.
The study was the culmination of lead author Chhaya Chaudhary’s PhD at the University of Auckland and was built on a range of studies in a research group that studied the literature and data on particular taxonomic groups in detail, including crustaceans, fish and worms.
The data were obtained from the Ocean Biodiversity Information System (OBIS), a freely accessible online world database whose establishment was led by the University’s Professor Mark Costello as part of the Census of Marine Life, a global marine discovery programme from 2000 to 2010.