Octopuses have been around for hundreds of millions of years, but most only live for a few years, dying soon after mating or laying eggs. With octopus catches doubling in recent years to meet the demands of a growing global population, ensuring the sustainability of octopus fisheries has become crucial. To achieve this, an accurate, reliable, cost-effective, and easy-to-use method to determine an octopus’s age and estimate their growth and reproductive rates is needed.
A team of Australian scientists has developed the world’s first practical guide to aging octopus, published in the Marine and Freshwater Research Journal. By using growth rings on the beaks and stylets of octopuses, University of South Australia marine scientists have created a tool for managing and assessing octopus fisheries. Understanding an octopus’s age allows researchers to determine the impact of fishing rates on the population and helps in maintaining sustainable fisheries.
The guide was developed by UniSA PhD student Erica Durante and research assistant Louise Hosking under the supervision of Dr Zoe Doubleday. It is part of a larger study led by Dr Karina Hall of the NSW Department of Primary Industries and funded by the Fisheries Research and Development Corporation. By knowing the age of octopuses, researchers can estimate their growth and reproductive rates, ensuring that fishing practices are sustainable and do not deplete the population.
Aging octopuses can be challenging as their growth rings represent days rather than years, and methods need to be customized for each species. With an estimated 400,000 octopuses harvested annually from around 90 countries, the pressure on octopus stocks is increasing. By making this guide accessible to everyone, the researchers hope to contribute to the sustainability of fisheries and ensure the survival and thriving of this ancient animal.
Understanding an octopus’s age is crucial for the conservation and management of the species, whether they are being fished or not. Knowing the maturation rate of octopuses helps in preventing the fishing out of immature individuals before they have had a chance to breed. By determining the age of octopuses, researchers can also estimate how long it takes for them to reach maturity and reproduce.
By publishing this practical guide, the Australian scientists aim to preserve the practical scientific knowledge necessary for aging octopuses and to ensure the sustainability of octopus fisheries. This knowledge is essential for managing fisheries, protecting octopus populations, and ensuring that this incredible animal continues to survive and thrive in the face of increasing fishing pressures worldwide.
