Secretariat of the Pacific Community ISSN 1025-4943 Issue 33 – May 2013 BECHE-DE-MER information bulletin Inside this issue Editorial Change in weight of sea cucumbers during processing: Ten common This issue of SPC Beche-de-mer Information Bulletin contains eight articles commercial species in tonga and communications from several countries. It also includes abstracts about sea P. Ngaluafe and J. Lee p. 3 cucumbers that were presented at the 14th International Echinoderm Conference First insight into Colombian Caribbean that was held in Brussels in August. sea cucumbers and sea cucumber fishery The first article (p. 3) comes from Tonga. Poasi Ngaluafe and Jessica Lee analyse A. Rodriguez Forero et al. p. 9 the change in weight of ten common commercial sea cucumbers. They discuss the possible reasons for the discrepancy they observe between their results and Strategies for improving survivorship of hatchery-reared juvenile Holothuria previous ones, and the implications for fisheries management in Tonga. scabra in community-managed sea cucumber farms We are also very pleased to present some insights about sea cucumbers and sea A. Rougier et al. p. 14 cucumber fisheries in the Colombian Caribbean. The article is from the team of Holothurian abundance, richness and Adriana Rodríguez Forero (p. 9). They report on species that could be new for the population densities, comparing sites Caribbean and conclude with stressing the importance of initiating a management with different degrees of exploitation in plan for the Colombian fishery resource. the shallow lagoons of Mauritius K. Lampe p. 23 Some news also from Madagascar, where Antoine Rougier et al. (p. 14) talk about Artificial breeding and larval rearing of the strategies for improving survivorship of hatchery-reared juvenile Holothuria three tropical sea cucumber species: scabra in community-managed sea cucumber farms. Their findings indicate that Holothuria scabra, Pseudocolochirus violaceus and Colochirus quadrangularis technical solutions must be coupled with active management to maximise the in Sri Lanka survivorship of juveniles. A. Kumara et al. p. 30 From the shallow lagoons of western and southern Mauritius, Katrin Lampe The ability of holothurians to select sedi- (p. 23) presents statistics on a total of 3411 holothurians, comparing their diver- ment particles and organic matter sity and population densities in 16 survey sites that had been exploited to differ- K. Mezali and D.L. Soualili p. 38 ent degrees. Volunteer programme assesses the Holothuria arguinensis populations in Ria Ajith Kumara et al. (p. 30) worked on the breeding and larval rearing of three Formosa (southern Portugal) tropical sea cucumber species, Holothuria scabra, Pseudocolochirus violaceus M. González-Wangüemert et al. p. 44 and Colochirus quadrangularis, in Sri Lanka. They were successful in obtaining juveniles for the three species. Karim Mezali and Dina Lila Soualili (p. 38) analysed the ability of holothuri- Editor ans to select sediment particles and organic matter. For that, observations on the Igor Eeckhaut Marine Biology and bioimitation digestive contents of holothurians from shallow waters in Algeria are presented. 6, Av. Champ de Mars The results illustrate the diet specificity of the species. University of Mons 7000 Mons Belgium Email: [email protected] Mercedes González-Wangüemert et al. (p. 44) assessed the Holothuria arguin- Production ensis populations inside Ria Formosa (South Portugal) through a volunteer pro- Fisheries Information Section gramme. They found high densities but the values oscillated, depending on tran- SPC, BP D5, 98848 Noumea Cedex New Caledonia sects and habitats. Fax: +687 263818 Email: [email protected] Kalo Pakoa and Ian Bertram (p. 49) summarise the current state of sea cucumber www.spc.int/coastfish Produced with financial assistance fishery management in 12 Pacific Island countries or territories and the various from Australia, France and New Zealand actions that are taken to establish formal fishery management frameworks. 2 SPC Beche-de-mer Information Bulletin #33 – April 2013 Finally, we publish several short reports about underwater observations of Management state of Pacific sea cucum- ber fisheries spawning events of juveniles: from Rodrigue by Alexandre Bédier et al., K. Pakoa and I. Bertram p. 49 who also synthesises data recorded in previous bulletins (p. 53); from Papua New Guinea by Jeff Kinch et al. (p. 56); and from India by Hithesh Kardani Natural spawning observations on Rodri- gues Island, Indian Ocean and Mayurdan Gadhavi (p. 57). A. Bédier et al. p. 53 We received many communications, among which was a description of the Observation of juvenile Holothuria workshop (SCEAM Indian Ocean) that was held in Zanzibar in November fuscogilva on the fringing reefs of New 2012. We would also like to congratulate Thomas Plotieau, who recently Ireland Province, Papua New Guinea J. Kinch et al. p. 56 had his PhD thesis on H. scabra’s diet accepted. He specialised in the bac- teria assimilated from the sediment eaten by this species. Observation of juvenile Holothuria pardalis at Sikka Coast, Gulf of Kachchh Igor Eeckhaut H.K. Kardani and M.K. Gadhavi p. 57 Communications p. 58 Abstracts and new publications p. 67 PIMRIS is a joint project of five international on marine resources to users in the region, so as to organisations concerned with fisheries and marine support their rational development and management. resource development in the Pacific Islands region. PIMRIS activities include: the active collection, The project is executed by the Secretariat of the cataloguing and archiving of technical documents, Pacific Community (SPC), the Pacific Islands Forum especially ephemera (‘grey literature’); evaluation, Fisheries Agency (FFA), the University of the South repackaging and dissemination of information; Pacific (USP) and the Pacific Regional Environment provision of literature searches, question-and-answer Programme (SPREP). This bulletin is produced by services and bibliographic support; and assistance SPC as part of its commitment to PIMRIS. The aim of Pacific Islands Marine Resources with the development of in-country reference PIMRIS is to improve the availability of information Information System collections and databases on marine resources. SPC Beche-de-mer Information Bulletin #33 – May 2013 3 Change in weight of sea cucumbers during processing: Ten common commercial species in Tonga Poasi Ngaluafe1* and Jessica Lee2 Abstract Accurately estimating the weight of live sea cucumber from the weight of dried beche-de-mer is important for national fisheries data, for standardising data collected from surveys or export records, and for inform- ing management decisions and regulating fisheries quotas. Different sea cucumber species lose different proportions of their body weight through processing, so conversion ratios are best calculated on a species- by-species basis. This study measured the proportional change in weight of ten sea cucumber species in Tonga over the various stages of processing. The aim of the study was to fill knowledge gaps by providing conversion ratios for species for which no relevant data exist, such as Actinopyga lecanora, Bohadschia argus, B. similis, B. vitiensis and Holothuria coluber. For other species studied, the conversion ratios were compared with the ratios calculated in previous studies, with this study generally producing higher conversion ratios (i.e. less weight lost through processing). We discuss the possible reasons for this discrepancy, the implica- tions for fisheries management in Tonga, and the need for further studies. Introduction studies have been carried out in Tonga. Comparing the ratios obtained in this study to those reported Sometimes, weight data for sea cucumbers are in previous studies will help the Tongan Fisheries available for only one stage of processing, whether Department to decide whether the ratios currently this be the pre-processing stage (fresh weight), an being used for catch calculations are appropriate intermediate processing stage or, more commonly, to Tonga. the fully processed dried product (beche-de-mer). Conversion ratios allow weight data to be com- Methods pared using a common unit for analysis. If accu- rate conversion rates are available for a particular The methods followed were based on the methods species, the processed weight can be used in order used by Purcell et al. (2009), with some variations. to estimate the weight (and numbers, if average Length conversion information was not considered weights are available) of fresh sea cucumbers that in this study, as it is not as relevant as weight con- were processed. version information for commercial export calcula- tions in Tonga. Some previous studies have determined the aver- age change in weight from whole, unprocessed The study was conducted in Uiha on the island of sea cucumbers to dried beche-de-mer for several Felemea, in the Ha’apai group of islands in Tonga. common tropical species (Conand 1990; Skewes Sea cucumbers were collected by local fishers and et al. 2004; Purcell et al. 2009; Lavitra et al. 2009). brought to shore in tubs. A sample size of twenty- However, there are still knowledge gaps for some five individuals was weighed for each species, with commercial species, several of which have been the exception of Thelenota ananas (prickly redfish), addressed in this study. with only 14 individuals recorded, and Actinopyga sp. (affinity flammea) with only two individuals In addition to differences