According to a new study, involving the University of Southampton, the speculations of increase in jellyfish in the oceans seem to be overstated. The new study shows no strong evidence of any such increase in jellyfish population for the past two centuries, reports Science Daily.
During the study it was found that global jellyfish populations undergo some variance with decadal rising and falling. There was a rise in the 1990s and early 2000s which led to the current view of a global increase in jellyfish. Similarly a substantial increase in jellyfish population in 1970s was overlooked due to lack of awareness of global scale problems and less information sharing options.
"Sustained monitoring is now required over the next decade to shed light with statistical confidence whether the weak increasing linear trend in jellyfish populations after 1970 is an actual shift in the baseline or part of a larger oscillation," Dr. Cathy Lucas, a marine biologist at the University of Southampton said, according to Science Daily.
There have been certain regions which saw an increase in jellyfish population and certain places remained stable over the decadal periods. There were fluctuation in the number of jellyfish rise and fall and few places actually saw a decrease in jellyfish count over the period of time.
"There are major consequences for getting the answer correct for tourism, fisheries and management decisions as they relate to climate change and changing ocean environments," said Dr Lucas, according to Science Daily. "The important aspect about our work is that we have provided the long-term baseline backed with all data available to science, which will enable scientists to build on and eventually repeat these analyses in a decade or two from now to determine whether there has been a real increase in jellyfish."
"The realisation that jellyfish synchronously rise and fall around the world should now lead researchers to search for the long-term natural and climate drivers of jellyfish populations, in addition to begin monitoring jellyfish in open ocean and Southern Hemisphere regions that are underrepresented in our analyses," said lead author Dr. Rob Condon, marine scientist at the Dauphin Island Sea Lab (DISL) in Alabama, reports Science Daily.
There are significant damages that can be caused by jellyfish blooms to fisheries, tourism and other human industries, and the current findings show the rise and fall in jellyfish is one threat that society may face and be prepared for.
The findings of this study are published online in the latest issue of Proceedings of the National Academy of Sciences-PNAS.
