MIAMI — The oceans are warming and coral reefs are dying, but octopuses, squids and cuttlefish appear to be thriving, with their numbers steadily rising over the past 60 years, researchers said Monday.
The findings, based on a global database of cephalopod catch rates devised by researchers at the University of Adelaide, were reported in the journal Current Biology.
“Our analysis showed that cephalopod abundance has increased since the 1950s, a result that was remarkably consistent across three distinct groups,” said lead author Zoe Doubleday.
She said cephalopods may be benefiting from the changing environment because of their “unique set of biological traits, including rapid growth, short lifespans and flexible development.”
The study did not say how many more such creatures there are today than in the 1950s, or give any figures for the rate of increase.
However, the study said the rise in abundance was clear across the globe, based on samples from all the world’s major oceans.
Previous studies have also pointed to warming temperatures as a boon to cephalopods, which may have fewer predators as global fish stocks decline.
But researchers said more work is needed to uncover the factors at play, and the future implications.
The current project got started as an investigation into declining numbers of the Giant Australian cuttlefish, said Doubleday.
“There has been a lot of concern over declining numbers of the iconic Giant Australian cuttlefish at the world-renowned breeding ground in South Australia’s Spencer Gulf,” she said.
“To determine if similar patterns were occurring elsewhere, we compiled this global-scale database,” she added.
“Surprisingly, analysis revealed that cephalopods, as a whole, are in fact increasing; and since this study, cuttlefish numbers from this iconic population near Whyalla are luckily bouncing back.” — AFP