This study assessed the mangrove community structure, relative seasonal abundance of all size classes of crabs (catch per unit effort or CPUE) and percent composition of the catch in two collection grounds in Pambujan and Rosario, Northern Samar using cylindrical bamboo traps and lift nets. Mangroves in Pambujan was dominated by Avicennia marina and A. alba. The initial total count of mangrove trees (67 stems ha^-1) was slightly higher compared with the final count (61 stems ha^-1). On the other hand, mangroves in Rosario was dominated by Rhizophora apiculata and R. stylosa. The total count of mangrove trees was higher in the initial (108 stems ha^-1) compared with the final (46 stems ha-1). However, saplings and seedlings increased in both sites after 18 months. Mean CPUE ranged from 0.04 to 0.4 crabs using cylindrical bamboo traps in the monthly spring tide sampling for 19 months in Pambujan. High mean CPUE was recorded in February and August 2008. Mean CPUE ranged from 0.04 to 0.41 crabs using lift nets in the monthly spring tide sampling. The highest mean CPUE was noted in August. The initial and final CPUE were comparable. In Rosario, mean CPUE ranged from 0.3 to 1.78 crabs monthly caught in cylindrical bamboo traps and from 0.04 to 0.77 crabs in lift nets. In general, the number of crabs caught in both traps was higher in Rosario than in Pambujan. Mud crab ranged from 2.02-72.2% of the monthly total catch in lift nets in Pambujan. Other species of crabs ranging from 27.78 to 86.36% were the dominant catch in several months. In Rosario, mud crab ranged from 12.5 to 82.35% of the monthly total catch. The catch composition of the cylindrical bamboo traps was more varied compared with lift nets in both sites. The decrease in the population of mud crabs may also be associated with the decrease in mangrove trees. With the continuous cutting of trees and regular extraction of all sizes of mud crabs, the industry may no longer become sustainable. This paper is the first to be done on the assessment of the mud crab population in Northern Samar and the information gathered can be used as basis for the development and improvement of the existing fisheries legislation for the conservation and management of the remaining wild resources.

Mud crab farming has long been established in the Philippines and the country is the second top producer in the world. Except for Scylla paramamosain, the three other species, S. serrata, S. tranquebarica and S. olivacea are commonly found in the country, but S. serrata is the preferred species for farming. Crab seeds for farming are mainly from the wild and in recent years, a small percentage from the hatchery. Due to the apparent decline of the wild crab stocks, provincial and municipal ordinances have been issued by a number of Local Government Units (LGUs) along with the Bureau of Fisheries and Aquatic Resources (BFAR) to conserve and manage the remaining resources. From the hatchery, megalopa or crab instars are grown in net cages installed in the nursery pond. Mud crab farming engages mostly in long-term grow-out culture of juvenile crabs to market size for 3-5 months, short-term fattening of lean crabs for 15-45 days, and recently, soft-shell crab production. Polyculture of juvenile crabs to market size with one to three other commodities in earthen brackishwater ponds is usually practiced. Mud crabs for soft-shell crab production are mainly from the wild, while SEAFDEC/AQD demonstrates the use of hatchery-produced juvenile mud crabs as seedstock. Refinement is continuously being done to improve the economic viability of producing crabs, although basic technologies have been developed for all phases of culture (hatchery, nursery, grow-out, fattening and soft shell crab production). The major issues facing the industry are the lack of seedstock, difficulty of zoea 5 to molt to megalopa stage, cannibalism particularly at the nursery phase, species identification at the juvenile stage, use of fish as aquafeed, diseases, effects of climate change and quality of crabs at postharvest. In 2012, the Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development (PCAARRD) of the Department of Science and Technology (DOST) started funding projects under the National Mud Crab Science and Technology Program (NMCSTP) to address these issues. The major aim of the Program was to improve the production, profitability and sustainability of crab farming. SEAFDEC/AQD leads in capacity building with focus on the sustainability of the mud crab industry. Various collaborations and research studies on mud crab culture enabled SEAFDEC/AQD to package mud crab technologies, conduct local and international training courses and on-site technology demonstrations, and publish extension manuals and scientific publications since the mid1990s. Research and Development activities have been translated into improved production. With the recent developments and refinements of technologies, it is expected that the Philippines will increase its production by 25-50% in the next 5 years.