Unlike the declining populations of many fish species, the number of octopus, cuttlefish and squid has increased in the world’s oceans over the past 60 years, a University of Adelaide study has found. The international team, led by researchers from the University’s Environment Institute, compiled a global database of cephalopod catch rates to investigate long-term trends in abundance. “Our analyses showed that cephalopod abundance has increased since the 1950s, a result that was remarkably consistent across three distinct groups,” says lead author Dr Zoë Doubleday, Research Fellow in the Environment Institute and School of Biological Sciences. “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. “As such, the increase in abundance has significant and complex implications for both the marine food web and us,” says Dr Doubleday.