By Natalie Parletta
As the oceans have warmed by one degree Celsius since pre-industrial times, the abundance of marine life has changed significantly from plankton and fish to mammals, seabirds and macroalgae.
The populations of plants and marine animals in cooler waters have grown as previously uninhabitable habitats become more viable, while those near warmer waters are declining.
This finding comes from a global analysis of data for more than 300 marine species collected over the past century and is published in the journal Current biology.
“Some marine species seem to be benefiting from climate change, especially some populations at the Poleward borders that can now thrive,” said co-lead author Louise Rutterford of the University of Bristol, UK.
“In the meantime, some marine life is suffering because it cannot adapt quickly enough to survive the warming. This is particularly noticeable in populations near the equator.”
Both trends could adversely affect species behavior and the broader ecosystem – including predators, prey, and food availability – and could point to a further loss of marine species as ocean temperatures are expected to continue to rise to 1.5 degrees by 2050.
“We see that species such as emperor penguins are less common when the water at the equator gets too warm,” says lead author Martin Genner.
Other species that move from warmer to cooler waters are Atlantic herring and Adèlie penguins.
While the shifts could improve hot water fishing opportunities in new habitats, ideal conditions for hot water parasites to thrive could also be created, which could disrupt the aquaculture industry and livelihood on the coast.
Based on smaller regional studies, the authors predicted that temperature changes would affect the frequency of marine organisms that function physiologically within narrow thermal tolerance limits.
However, human activities have a different impact on the ocean and cause habitat and storm destruction related to climate change, salinity, and acidification, which must be considered along with a thorough life history and physiological and environmental characteristics of all types.
In order to get a clearer, global picture of the frequency patterns in relation to sea temperatures, the team collected data from 540 data sets from 1991 to 2016.
Their analysis found that overall species populations were much more likely to grow towards the poles and decrease near the equator, confirming that warming water affects their survival.
“Our study is therefore based on indications of climate-related local frequency changes and stands alongside climate-related changes in other biological parameters,” the authors write, “such as the overall distribution of species and temporal shifts in events in life history. ”
This is likely to continue and “have a further impact on local ship assemblies and the coastal industries dependent on them.”