INCREASING THE CATCH OF LOBSTER SEED FOR THE DEVELOPMENT OF SPINY LOBSTER AQUACULTURE IN INDONESIA

Lobster aquaculture is a proven strategy to supply increasing demand for spiny lobster, as in Vietnam, where annual production of farmed lobster reaches more than 1,500 tonnes, using a natural supply of post-larval lobster seed. Because of the development of puerulus fisheries to supply seed lobster for aquaculture purposes, there is growing interest in gaining a greater understanding of puerulus settlement to enable improvement of fishing techniques to maximise the catch. Such improvements will involve use of manufactured traps comprised of various materials to simulate "natural'' substrates, and if possible exceed natural settlement rates.

In Indonesia, particularly in Lombok, a significant resource of naturally settling lobster pueruli has been identified and a fishery established that in 2013 captured around 3-5 million pueruli each year. A recent study assessing the effectiveness of the most common puerulus fishing equipment used in Lombok revealed that traps made from disused cement bags were the most effective among those examined. Further assessment and development of trap design may lead to greater catch rates.

To maximise catch rates of pueruli effectively involves habitat enhancement to create an abundance of suitable settlement substrates that increase successful settlement and survival of pueruli beyond what would occur naturally. Such habitat is likely to afford protection from predation and natural environmental perturbations and confer significantly higher survival rates than would occur if no such manufactured habitat was available.

A series of experiments were performed to build on knowledge gained to date about the behaviour and substrate preferences of settling pueruli, by examining aspects of trap design and substrate surface characteristics to enhance catch rates. A series of tank-based experiments was used to examine preferences to various aspects of trap design, and preferred design characteristics were then tested in a field experiment. The results of this work are presented.