Innovative DNA methods to age blue swimming crabs in Indonesia

Amount awarded: £5,000

This project is using innovative DNA methods to age blue swimming crabs in the Madura Island fishery improvement project (FIP) in Indonesia. Understanding the age structure of the fishery – the number of different ages you have in a population – is important for sustainable stock management.

Age structure affects growth, development, mortality, reproduction and vulnerability of animals, so it is an important indicator to understand the stock status. It will also help reveal what conservation measures may be suitable alongside sustainable fisheries measures such as stock enhancement. This involves boosting wild populations with artificially bred juveniles from a hatchery.

The FIP is led by the Indonesian Blue Swimming Crab Association (APRI). It has received two previous Ocean Stewardship Fund grants from the MSC in 2021, to support its progress towards sustainability.

This research, supported through the Student Research Grant, will help contribute to the stock assessments and development of harvest strategies – tools to help manage the stock sustainably into the future.

The fishery’s progress is also verified through the In-Transition to MSC program, and is expected to enter full assessment against the MSC Standard before the end of 2022.

What the project will do

Leni Maryani, Master’s Postgraduate Student Researcher at IPB University in Indonesia, will be using DNA techniques to test tissue samples of known, cultivated and unknown age specimens. This particular DNA method using methylation – which tests for genetic changes during biochemical processes – will be used to identify the age of the individual crabs.

It is an innovative approach for assessing stock status of the blue swimming crabs. It is thought it could also be more accurate and detailed than other methods of aging. The findings will be publicly available in an international journal, making the methods accessible to all relevant fisheries.