No abstract

Biophysical characteristics that affect the distribution of sandfish in the sea ranch were investigated to determine indicators for a suitable habitat for sandfish sea ranching. These include sediment grain size, organic matter (OM), chlorophyll a, pheophytin, penetrability, depth and seagrass cover. A total of 5864 hatchery-produced sandfish juveniles were released in seven batches in a 5-ha ranching site in Maliwaliw Island over a period of three years. The 5-ha ranch was divided into three zones, with Zone A (50 × 50 m) being the juvenile release site. Survey of the released sandfish was done quarterly from February 2016 until May 2017 and sediment collection done twice. A total of 750 sandfish weighing 10-600 g were recorded; 23% were <150 g, 59% were 151-350 g, 17% were 351-550 g, and 2% were >550 g. Distribution of substrate parameters between the different sea ranch zones showed no significant differences (p > 0.05). Visualized sediment grain-size data showed multiple cohorts of sandfish with varying sizes in different zones with predominantly medium and fine grains with relatively higher total OM and labile OM. Sandfish >351 g were found in deeper waters (>70 cm at low tide) with lower concentrations of labile OM and chlorophyll a, and higher pheophytin. Sandfish <350 g were found in areas with higher labile OM, higher chlorophyll a and lower pheophytin. Results of this study indicate the need for a sandfish sea ranch site with water depth >30 cm at low tide, and varying sediment particle size and composition to support the different stages of growth and development of sandfish.

This study investigates the potential of locally available mosquito nets as an alternative material for sandfish ocean nurseries. Mosquito nets (~ 2 mm mesh) were designed into single (SL), double (DL), and triple-layered (TL) to approximate the conventional hapa (CH) with ~ 1 mm mesh normally used in sandfish ocean nurseries. The study was conducted in Maliwaliw island and in a cove in Buyayawon both located in Eastern Samar, Philippines. Results showed that TL had the highest juvenile survival (35.93 ± 10.56%) in Maliwaliw, which was significantly different (p < 0.05) from SL and DL. The DL design showed the highest survival (25.23 ± 17.15%) in Buyayawon by day 60, followed by TL (21.37 ± 3.11%), although not statistically significant. On the other hand, average growth rate was highest in SL in both sites where survival was also the lowest. Biomass, however, was the highest in DL in Buyayawon (1,014 ± 266 g m-2) followed by TL in Maliwaliw (925 ± 107 g m-2). Sandfish juvenile survival in DL and TL were higher than those in the CH in both sites suggesting that mosquito nets can indeed be used as an alternative material for rearing early-stage sandfish juveniles in floating ocean nurseries.

Since the 1970s, Samar and Leyte islands had a thriving sea cucumber fishery but have rapidly declined over the years. In Maliwaliw Island, anecdotal accounts validated by the community revealed that the island had a brisk sea cucumber fishery but collapsed due to uncontrolled collection. In 2013, a sandfish sea ranching project was implemented in Maliwaliw Island, Salcedo, Eastern Samar, to bring back the sandfish that has disappeared from the area, and subsequently provide a supplemental livelihood to the local fishers. This study was conducted to investigate the impacts and lessons learned from the sandfish project. Recruitment of wild stock, increased community knowledge of sea cucumber biology and ecology, additional income through sandfish bycatch, and perceived enhancement of the coastal marine environment of the island were among the positive gains from the project identified by the respondents. On the other hand, poaching by fishers from neighboring communities resulting in inter-community conflicts was a major challenge. Clearly, the sandfish sea ranching project in Maliwaliw achieved ecological, social, and economic impacts on the project participants and the community. However, these gains need to be strengthened with effective management measures including size regulation to sustain the sea cucumber fishery in the area.

Blue swimming crab (BSC) industry contributes considerably to the region's economy. Despite the extensive harvesting and marketing activities, there is no information on the people who make a living out of the BSC resource. This study provides suggestions to improve the management of BSC fishery by looking into the crabbers' socio-demographic profile, crabbing gears, crabbing practices, and awareness of regulatory measures regarding BSC fishery management. Semi-structured interviews were conducted from April to August 2014 in selected crabbing municipalities in five major fishing grounds of Eastern Visayas. Generally, the income of the crabbers and their family is way below the poverty threshold indicated for Eastern Visayas. This condition is aggravated by the lack of formal education among the crabbers and their members, which limits them from engaging in other livelihood opportunities. The marginal contribution from other livelihood sources to the household income is still insufficient to support other needs, particularly education. To increase the daily catch, crabbers resorted to unsustainable and destructive crabbing practices, which depletes further the resources. To address these issues, LGUs in partnership with other concerned organizations should formulate and implement programs and projects that will alleviate the living conditions of the crabbers. Moreover, the LGUs should implement national plans along with local legislation to ensure the regulation of BSC catching and selling. Crabbers must practice sustainable, cost-effective, and non-destructive crabbing activity to improve BSC production. Further studies into the biology, seasonality, and stock assessment are needed to craft appropriate science-based management framework.