Project to launch in Mandurah to track numbers of juvenile western rock lobsters

Photo: Supplied.
Photo: Supplied.

A new project to survey the number of juvenile western rock lobsters in shallow waters will launch in Mandurah next year.

The three-year scheme aims to ensure the continued sustainability of the valuable fishery, which is worth $450 million in WA.

Researchers will survey the juvenile numbers between Kalbarri and Mandurah, as well as assess changes to the marine habitat that could impact on the population.

The Department of Primary Industries and Regional Development will run the project, working closely with the commercial industry and researchers from the University of Western Australia to design the survey.

Six-hundred modified lobster pots, designed to catch as many juveniles as possible, will be spread across 12 locations along the coastline.

These pots will be set twice with catches monitored and data provided from 1200 different locations.

Researchers will then analyse the numbers, size, sex and health of the lobsters, and compare the data against the settlement of baby lobsters sampled as part of another survey.

Department principal research scientist Simon de Lestang said all undersize lobsters would be returned to their individual reef locations.

"Many of the pots will also have a camera attached to help map the surrounding marine habitat, allowing the department to monitor any environmental changes," he said.

"Over the past nine years, the abundance of juvenile western rock lobsters have started to diverge from their historical relationships.

"It is thought a marine heat wave in 2011 may have changed the marine environment in some areas of the fishery, impacting on the survival of juvenile lobsters.

"This project will help us to get a better understanding of the juvenile population and the marine habitat, allowing us to provide further information to industry on the future management of the fishery."

The project is funded throughthe Fisheries Research and Development Corporation.

The surveys will start in March 2021.