Octopocalypse now: Cephalopod populations booming

24 May 2016

This is a photograph of giant Australian cuttlefish (Sepia apama), Spencer Gulf, South Australia, via Scott Portelli

Climate change looks to be beneficial for cephalopods, with “remarkable” octopus, cuttlefish and squid population numbers going upwards for six decades now.

The octopus. The cuttlefish. The squid. These are all part of the cephalopod family, a family going through quite the boom.

While the effects of climate change – warmer water, higher water, altering weather patterns – have so far proved disastrous for many animals on the planet, there’s always room for a winner.

According to a new report in Current Biology, for 60 years now, the oceans, rock pools and even bays of this planet have had to make room for a growing number of tentacled swimmers.

Looking at 35 different cephalopod species over catch-rate data from 1953 to 2013, Zoë Doubleday and her team found that many are on the rise.

According to the researchers, the thought now is that cephalopod populations are benefitting from the stark change in environment over recent decades.

Giant Australian cuttlefish (Sepia apama), Spencer Gulf, South Australia, via David Wiltshire

Giant Australian cuttlefish (Sepia apama), Spencer Gulf, South Australia, via David Wiltshire

“The consistency was the biggest surprise,” said Doubleday, noting the remarkable variety of preferred environments for different species.

“The fact that we observed consistent, long-term increases in three diverse groups of cephalopods, which inhabit everything from rock pools to open oceans, is remarkable.”

Doubleday said the population spurt could prove costly for some sea life, and beneficial for others.

For example, certain prey will no doubt come under more stress with more cuttlefish and squid around, which could have a knock-on effect further down, or up, the food chain. Take this crab chase, for example.

“Conversely, increases in cephalopod populations could benefit marine predators that are reliant on them for food, as well as human communities reliant on them as a fisheries resource.”

Gordon Hunt was a journalist with Silicon Republic