Echinoderm fisheries: their culture, conservation, bioactive compounds and therapeutic applications

Abstract

The Indo-Pacific region sometimes referred to as the Indo-West Pacific, is considered to be the richest marine biodiversity hotspot comprising unique species of echinoderms, molluscs, shrimps, crabs and fishes. These bioresources provide excellent opportunities for the studies of breeding biology, reproductive ecology, aquaculture, conservation, population genetics as well as species and speciation mechanisms of many diverged taxa. However, this interesting area is quite new and yet to be fully explored and determined. In the bottom-dwelling sessile invertebrates, echinoderms belonging to the phylum Echinodermata, have been considered the high-valued marine bioresource, having profound biological, aquacultural, conservational, nutritional and pharmaceutical significance. Among them, the sea urchins and sea cucumbers are both commercially fished and heavily overexploited. In sea urchins, the harvested product is the gonad, commonly known as "Sea urchin Roe”, which has been long traditions of consuming as a high delicacy food in Asian, Mediterranean and Western Hemisphere countries, and have long been used as a luxury food in Japan. The population of the Asian Pacific Region has been using it for a long time as a remedy for improving general living tone and treatment for a number of diseases. In the sea cucumber, the principal product is the boiled and dried body-wall or ‘bêche-de-mer’ for which there is an increasing demand in many tropical and subtropical countries. Sea cucumbers are also believed to exert wound healing and reduce arthritis pain in humans, hence are widely used in Asian folk medicine. However, due to a lack of proper management and conservation strategy in place, many sea urchin and sea cucumber fisheries are under threat. For this, cultivation of these species increasingly becomes a necessity, both for stock enhancement programs and as a means to meet the increasing market demand. Procedures for mass production of the tropical Holothuria scabra are now well established in China, India, Australia, Indonesia, the Maldives, the Solomon Islands, Philippines and Thailand. Alike many other marine organisms, echinoderms have been, and continue to be, examined as a source of biologically active compounds with biomedical applications. Most recently, a number of important bioactive compounds have been isolated from sea cucumbers and sea urchins, having distinctive biological and pharmacological activities including anti-angiogenic, anticancer, anticoagulant, anti-hypertension, anti-inflammatory, antimicrobial, antioxidant, antithrombotic, antitumor and wound healing activities. However, development patterns of echinoderm fisheries are largely expectable, often unsustainable and frequently too rapid for effective management. Proper steps should be undertaken on the potential ecosystem and human community consequences, appropriate aquaculture management strategies, and urge for better monitoring and reporting of catch and abundance, proper scientific research for stock enhancement and consideration of international biodiversity and trade regulations to ensure sustainable development and utilization of high-valued echinoderm fisheries to a greater extent.