Developing an independent shallow-water survey for the Western Rock Lobster Fishery: tracking pre-recruitment abundance and habitat change.

Forecasting lobster recruitment is important for the stock assessment of the West Coast Rock Lobster Managed Fishery (WCRLMF). This forecasting is based on two separate indices, puerulus settlement data and the catch rate of undersize lobster (60 - 76 mm CL) in shallow waters. The current method of measuring undersize lobster abundance (PRA) is based on catch data adjusted for multiple biases inherent in commercial monitoring, namely: water depth, water temperature, swell, fisher experience, pot type, escape gaps, pot pulling time, month and location. Fishery-independent survey data collection is time consuming and expensive (as multiple staff are required). To increase cost effectiveness (for this and other lobster surveys), a more efficient data collection system is needed. This investment will design and construct more efficient data recording tools and compare the data recorded with commercial monitoring of undersize lobsters and puerulus settlement data. The survey will also provide a platform for monitoring inshore WRL habitats to establish a baseline against which further research into the relationships between WRL and their near shore habitats can be undertaken to assist with detecting and quantifying habitat shifts that may impact the fishery.