​Sydney, May 24 (IANS) Unlike the declining populations of many fish species, the number of cephalopods - octopus, cuttlefish and squid -- has increased in the world's oceans over the past 60 years, new research has found.

To investigate long-term trends in its abundance, the international team of researchers compiled a global database of cephalopod catch rates 

"Our analyses showed that cephalopod abundance has increased since the 1950s, a result that was remarkably consistent across three distinct groups," said study lead author Zoe Doubleday from University of Adelaide in Australia.

"Cephalopods are often called 'weeds of the sea' as they have a unique set of biological traits, including rapid growth, short lifespans and flexible development. These allow them to adapt to changing environmental conditions (such as temperature) more quickly than many other marine species, which suggests that they may be benefiting from a changing ocean environment," Doubleday said.

The research stemmed from an investigation of declining numbers of the iconic Giant Australian cuttlefish, Doubleday said.

"Surprisingly, analyses 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," Doubleday noted.

The study was published in the journal Current Biology.

Cephalopods are found in all marine habitats and, as well as being voracious predators, they are also an important source of food for many marine species, as well as humans.

"As such, the increase in abundance has significant and complex implications for both the marine food web and us," Doubleday said.​