Introduction Sea cucumbers, or their dried form (beche-de-mer), are either eaten or used for medicinal purposes, and they have been a highly sought-after commodity in Asia for centuries (Toral-Granda et al. 2008). In the Pacific, most commercially valuable sea cucumbers occupy shallow clear seas, making the harvesting of these sessile and often conspicuous animals a rela- tively simple procedure. The combination of high value plus ease of capture has meant that many sea cucumber stocks around the world are now heavily overfished (Toral-Granda et al. 2008; Friedman et al. 2010). In Melanesia, sea cucumbers provide a very important source of income to rural coastal com- munities, being one of the few commodities that can be captured, processed locally, and then stored for extended periods of time (Kinch et al. 2008a). In shallow habitats, sea cucumbers are typically gleaned from reef flats and the reef crest on a low tide; in deeper areas, free divers use masks and fins to pick up sea cucumbers. In water that is too deep to easily access (typically below 20 m), free divers often use “bombs” — a small harpoon or series of straitened hooks inserted into a lead weight — to harpoon sea cucumbers that are beyond their reach. In Melanesia, the sea cucumber fishery is a multi- species fishery. In Papua New Guinea (PNG) for example, at least 26 species of sea cucumbers are harvested (Kinch et al. 2008b). Like other regions in the western Pacific, many sea cucumber fisheries in Melanesia have exhibited boom and bust cycles. Initially, sea cucumber fisheries target only one or two high value species, but once these stocks are over fished the fishery typically shifts its focus to lower value species (e.g. Lokani 1990; Lokani et al. 1996). Stocks of high value species are often quickly depleted, as evidenced by a case study on the Car- teret Islands that are northeast of Bougainville Island. In 1982, a beche-de-mer fishery targeting white and black teatfish (Holothuria fuscogilva and H. whitmaei) harvested approximately 10 t of sea cucumber from the Carteret Islands, but by 1983, total production had fallen to just over 2,000 kg and large, high grade beche-de-mer was virtually elimi- nated from the fishery (Dalzell 1990). Although sea cucumber fisheries typically follow boom and bust cycles, today, their high value, a lack of alternative income opportunities, a wide net- work of beche-de-mer purchasers, and the ease of processing and storing means that artisanal fisher- ies can continue to place considerable pressure on these fisheries well after stocks have been overex- ploited (Friedman et al. 2010). Several recent sur- veys in Melanesia have shown that sea cucumber stocks are widely overfished (e.g. Friedman et al. 2008; PNG National Fisheries Authority 2007; Ram- ofafia 2004; Ramohia 2006). 12 SPC Beche-de-mer Information Bulletin #31 – January 2011 Severely overfished sea cucumbers in the Autonomous Region of Bougainville Richard Hamilton 1 and Paul Lokani 2 Abstract In this paper we compare changes in populations of sea cucumbers that were surveyed on reef flats around Buka Island, in the Autonomous Region of Bougainville (ARB) in 1992 and 2008. Over this 16-year period, the abundances of eight species of sea cucumber declined dramatically. By 2008, six of the eight species sighted in 1992 and 2008 — Actinopyga echinites, A. miliaris, Bohadschia similis, Holothuria atra, H. coluber and H. scabra — had declined to between 1% and 5% of their 1992 abundances, providing quantitative evidence that the sea cucumber fishery in the ARB is severely overfished. In 1992, H. scabra, H. atra and B. similis constituted 92% of the sea cucumbers sighted on reef flats. These species were also the three most abundant sea cucumbers in the 2008 survey, comprising 62% of all sea cucumbers seen. Relatively high abundances of Actinopyga mauritiana and Bohadschia vitiensis were also sighted in 2008, species that were not encountered in the 1992 survey. Our findings provide support for the national moratorium that was placed on the sea cucumber fishery in Papua New Guinea in 2009, and we anticipate that many years of complete closure will be required before stocks in the ARB recover to 1992 levels. 1. The Nature Conservancy, Indo-Pacific Resource Centre, 51 Edmondstone Street, South Brisbane, QLD 4101, Australia. Email: rhamilton@tnc.org 2. The Nature Conservancy, Papua New Guinea Office, Suite 7, Monian Haus, Nita Street, Tabari Place, Boroko. Email: plokani@tnc.org