Inferring Stock Status of Painted Spiny Lobster (Panulirus versicolor) in Aru Islands Waters, Indonesia

Abstract

Three of six commercial spiny lobster species in Indonesian waters was found in Aru Islands waters which exploited continuously using drift gillnet and the catch was dominated by painted spiny lobster (Panulirus versicolor). To ensure the sustainability of the lobster stock, fisheries should be managed properly based on the best available science. In data-limited fisheries, length composition data are most common form information available for researchers and managers since its relatively cheap and simple to collect. In this study, we evaluate the stock status of P. versicolor in Aru Islands waters using three length-based methods: 1) length-converted catch curve (LCCC), 2) length-based spawning potential ratio (LB-SPR) and 3) length-based Bayesian biomass (LBB). The result showed that the mean length at catch of P. versicolor was 80.9 mm in carapace length. Furthermore, the three methods agree that the current status of painted spiny lobster stock seems to be fully exploited where the exploitation rate, the spawning potential ratio, and relative stock size (B/BMSY) were 54%, 35%, and 85%, respectively. Thus, for sustainability of this stock, it is highly recommended to catch P. versicolor at size greater than 80 mm in carapace length.