Trends, prospects and utilizations of sea cucumber fisheries in Malaysia

The holothurian or sea cucumber is one of the marine resources, which has been used not only as luxury food for certain countries but also as medicines. Because of its’ higher nutraceutical and pharmaceutical values, sea cucumber has become one of the most important products and it has high price in international market and thus provide an important employment and income source to the coastal communities in many Pacific island countries including Malaysia. They have been harvested for hundreds of years for trade with Asia and were probably one of the worthy exports from the Indo-Pacific islands. Unfortunately, the increase in demand and price, combined with the development of cash economies and growing coastal populations in many islands, has led to widespread overfishing of the resource across much of this region. There is a high level of interest in adoption of aquaculture and stock enhancement techniques to restore production phases,but different capacity levels require implementation of different techniques.Some Pacific island countries and territories have completed successful research trials of hatchery, nursery and release techniques,and now have capacity to scale up this activity but such types of research are still in the initial stage in Malaysia. Factors that work in favor of successful aquaculture include pristine marine environments,long familiarity with sea cucumbers as a commodity,and traditional marine tenure systems that in some places can provide a basis for management of released sea cucumbers.Currently,the exploitation of sea cucumber turns out to be excessive and disrupts its sustainability. Aquaculture is the best way to prevent this severe problem. The success of sea cucumber culture is very depending on broodstock management,seed availability and suitable food for larvae as well as juvenile along with appropriate grow-out culture techniques under controlled rearing protocols

Population and reproductive biology of a commercially important sea cucumber species, Stichopus horrens (Selenka, 1867) in Pangkor Island, Perak

To enhance our understanding on some of the important biological aspects of commonly targeted sea cucumber species in Malaysia, population and reproduction biology of a commercially important species of tropical sea cucumber, Stichopus horrens (Selenka, 1867) was investigated for a period of one year in Pangkor Island, Perak, Peninsular Malaysia. In total, 641 live individuals of S. horrens were collected from August 2015 to July 2016. Biometrics data were measured and population parameters were estimated using length-frequency data analyzed by FAO-ICLARM Stock Assessment Tool II (FiSAT-II) software. Reproduction was monitored through macroscopic and microscopic analyses of the gonads. The mean total weight and body length of the population was 96.80 ± 2.22 g and 15.23 ± 0.19 cm respectively. The length- weight relationship of the population was found to be W = 0.413L2.02. The growth parameter K and L∞ were estimated at 0.75 year-1 and 32.50 cm respectively. The total mortality was estimated at 2.38 year-1, natural mortality at 1.48 year-1 and fishing mortality at 0.90 year-1. The level of exploitation was at 0.38 and below the optimum level of 0.50. The gonad weight and tubule diameter were significantly different between male and female, being heavier and longer in the latter. The gonad index peaked at 0.76% in September, 2015 and gradually declined to the lowest at 0.03% in May, 2016 which was also proportional to the changes in tubule diameters. Histological examination of gonads revealed that the highest proportion of mature individuals was in September, 2015 when the spawning started and prolonged up to April, 2016 with the majority spawned in October, 2015. The size-class distribution of oocyte showed the dominant distribution of large mature oocytes (80–100 μm) from October to December 2015. The size at first sexual maturity was estimated at 20 cm in length and 135 g in total weight. The mean absolute fecundity was 1,100,727 (± 148,613 SE) and significant positive relationship between fecundity and size of the individuals was found. The population parameters revealed that this species is a relatively fast grower with high mortality. The findings also suggested that spawning of S. horrens might be seasonal with major spawning occurring from October to January. The results also demonstrated that spawning took place over a long period of time and mature species can be found almost throughout the year. The species also reaches late sexual maturity and the reproductive viability increase with increasing size and also probably ages. The prolonged release of gametes and availability of matured adults throughout the year might facilitate sustainable aquaculture program of this species. The period of enhanced spawning observed will also contribute to better management of broodstocks in such program to a greater extent