Surviving and thriving in the sea

Selective focus photo of Octopus

Cephalopods are voracious and adaptable predators and inhabit all marine environments.

They’re an important food source for marine mammals, some fish and seabirds.

Squid, octopus and cuttlefish are the best-known members of the cephalopod family, but until recently were not well known at all. We are doing a lot to address this, contributing valuable insights into the way cephalopods are coping with changes to the marine environment.

Our researchers began in the early 2000s with an intensive study of the unique giant Australian cuttlefish. Giant Australian cuttlefish are internationally recognised as an iconic natural phenomenon due to their massive breeding aggregation in South Australia.

Our interest in examining long-term trends in abundance of giant Australian cuttlefish and whether the patterns were cyclical took these studies global.

The research team attracted worldwide attention in 2016 with a groundbreaking study that tracked trends in cephalopod numbers over six decades.

With many marine species in decline the big surprise of the 2016 study was that cephalopods seem to be doing well.

Sixty years of data drawn from numerous international sources, including national fisheries records and scientific surveys, showed populations have increased universally through time.

This may mean humans are inadvertently giving cephalopods a competitive edge by changing the environment so rapidly.

So the research team have gone on to explore how human activity influences these numbers and the implications for fisheries.

Cephalopods grow very quickly, have short lifespans and can be very flexible in the timing of their major lifecycle events, such as when they reach sexual maturity. They adapt to changing environmental conditions much faster than many other marine species.

Key questions include whether we can balance out the human pressure by fishing more of the species that are able to adapt quickly and less of those that can’t. This can then inform future approaches to human fishing and managing marine environments.

Tagged in Environment, sustainability and climate change, marine ecology, cephalopods, fisheries management