Assessment of Postharvest Losses Due to Catching Undersized Fishery Commodities and Size-Dependent Pricing in the Philippines

The continuing decline in catch rates instigates various fishing adjustments to keep up with the demands of a growing population. Fishery resources are being caught before they can attain their optimum harvestable size. Undersized catch elicits lower economic value; thus, considered as losses in postharvest fisheries. The present study focused on generating actual data on the volume of undersized catches in selected landing sites in the Philippines. It aims to quantify the magnitude of postharvest and financial losses incurred from catching fishery commodities below their marketable sizes. The estimated loss at 0.97% and 4.02% for capture and aquaculture commodities, respectively, was equivalent to PHP 15,235,290 financial loss. Estimation of losses by commodity showed that squid recorded the highest at 20.14%, followed by tilapia (9.61%), blue swimming crab (4.48%), shrimp (2.75%), small pelagics (1.98%), mussel (1.46%), oceanic tuna (0.91%), by-catch (0.79%), milkfish (0.09%), and oyster (0.02%). Excessive catching of undersized BSC and squid in Western Visayas may lead to overexploitation of resources and may adversely affect subsequent recruitment in the long run. The study's results indicate that catching undersized species could lead to substantial postharvest losses and subsequent loss of potential revenue to the industry players. Allowing the stocks to attain their maximum biomass level will minimize postharvest losses; thus, maximizing utilization of resources and benefits derived from the sector. Unrestrained catching of undersized fishery commodities undermines resource sustainability, economic potential, and food security. The strengthening of regulatory frameworks is, therefore, necessary to address both economic and ecological impacts.

Marine Mammals Occurring in the Negros Occidental Coastal Wetlands Conservation Area, Philippines

The Negros Occidental Coastal Wetlands Conservation Area (NOCWCA) is the Philippines’ 7th Ramsar Site of Wetlands of International Importance. It spans 89,607 ha comprising the municipal waters of 10 adjacent towns and municipalities. Its waters are part of the Guimaras Strait in the north and the Panay Gulf in the south. This research aimed to assess marine mammal diversity in these coastal wetlands. Marine mammal species here were documented through strandings, interview surveys, and boat surveys. Ten species of marine mammals, including the dugong (Dugong dugon), have stranded in the NOCWCA for the past ten years. Three species were encountered in the boat surveys: Indo-Pacific bottlenose dolphin (Tursiops aduncus), Long-snouted spinner dolphin (Stenella longirostris longirostris), and Irrawaddy dolphin (Orcaella brevirostris). All species were encountered in close proximity to fishing boats, indicating possible interactions. The presence of these marine mammals here highlights the importance of these areas as essential habitats.

Assessing the Viability of Commercial Media for the Mass Culture of Chaetoceros muelleri

The microalgae Chaetoceros muelleri is considered a highly nutritious feed for the cultured larvae of the tropical sea cucumber Holothuria scabra. Due to the cost of analytical grade culture media used in the production of C. muelleri, there is a need to evaluate cheap alternative commercial media to decrease the cost of producing quality live microalgal food. In this study, two different indoor batch culture systems (1 L glass bottles and 10 L plastic carboys) were used to evaluate the effectiveness of two conventional (modified F/2 and Walne’s) and one commercial (Epizyme AGP complete) microalgal culture media. Results of the 1 L glass bottle experiment showed that the peak cell density of C. muelleri in AGP (1,241 ± 116 x 104 cells ml-1) was not significantly different from the modified F/2 (1,584 ± 41 x 104 cells ml-1) and Walne’s medium (1,319 ± 162 x 104 cells ml-1) (Kruskal-Wallis test, p=0.78). Likewise, in the plastic carboy experiment, the maximum cell density of C. muelleri in Walne’s medium (750 ± 144 x 104 cells ml-1) and F/2 medium (653 ± 79 x 104 cells ml-1) were higher, but not significantly different from AGP (496 ± 184 x 104 cells ml-1) (Kruskal-Wallis test, p=0.43). The highest growth rate in the glass bottle cultures was the modified F/2 (0.38 div day-1), while AGP was the lowest (0.34 div. day-1). On the other hand, in carboy culture, AGP was higher (0.17 div.day-1) compared to modified F/2 (0.15 div. day-1) and Walne’s medium (0.13 div. day-1). The exponential growth phase was similar in the glass bottles, while in the carboy, the exponential phase was reached at a shorter time in the AGP treatment than those in the modified F/2 and Walne’s media. The findings showed that AGP medium is an adequate alternative to replace the conventional media (modified F/2 and Walne’s) during the secondary stock culture for C. muelleri. The viability of using cheaper and more readily available commercial AGP media for the indoor culture production of C. muelleri can contribute to cost-effective scaling-up of the hatchery production of quality H. scabra larvae and early juveniles.

Utilization of Shrimp Head Wastes into Powder Form as Raw Material for Value-Added Products

Shrimp processing industries produce large amounts of wastes in the form of shrimp heads, shells, and tails, which are more or less 50% of the raw materials. Improper disposal of these nutrient-rich wastes can cause environmental problems if not duly managed. This study aims to utilize Penaeus monodon shrimp head wastes into powder form using a cabinet type drier and establish the processing yield and important product qualities. Two treatments of shrimp head powders were studied: shrimp head powder with carapace (SHPwc) and shrimp head powder without carapace (SHPwoc). The yields obtained were 26.72% for SHPwc while 20.42% for SHPwoc; both are considered to have significant value since both are produced from wastes. Both products have satisfactory water activity levels; however, the bulk density was high, and the solubility was lower than other published powdered seafood by-products. Both products have light orange or brown color: however, in both odor and flavor, SHPwoc had a higher mean general acceptability, with “like slightly-like moderately” results. SHPwoc was subjected to a shelf-life study with added salt and ascorbic acid preservatives. Monthly analyses revealed that the microbiological parameters are still within limits, and both moisture and pH values were acceptable after eight months of storage at ambient temperature (28-30°C). However, the peroxide value is acceptable until only the sixth month, which signifies the end of shelf-life based on theoretical sensory changes. The results of this study show the promising significance of utilizing shrimp processing wastes into seafoodbased products.

Efficient Fishing Method to Control the Population of Rice Eel, Monopterus albus (Synbranchidae) in Rice Fields in Cagayan Valley, Philippines

Rice eel (Monopterus albus) was introduced in the Philippines in 1905 as an aquaculture species without a thorough evaluation of its possible negative impact on the environment. In Cagayan Valley Region, it is being considered as a pest due to the economic loss it brought to farmers as it bore holes on the dikes, draining the water from the rice field, thus, contributing to the additional expense of the farmers. However, from the economic point of view, the species offered great potential as an export commodity due to its broad export market in East Asian countries. Hence, this study was conducted to determine the most efficient and effective method of controlling the proliferation of rice eel in rice fields in the Cagayan Valley region while preserving its integrity as an export commodity. Twelve (12) municipalities were chosen as the study sites based on validated reports of the high occurrence of rice eel. Three fishing methods, namely, fish trap (FT), hook and line (HL), and electrofishing (EF) gadget, were utilized. These gears were set during the dry and wet seasons. Catch and catch per unit effort (CPUE) were used to determine gear efficiency, while monetary values, net income, and ROI were used to assess the profitability of the gears. Results showed that electrofishing gadgets exhibit greater efficiency among the three fishing gears. The EF gadget also has the highest CPUE (4 individuals) per hour while only around 0–1 per hour for FT and HL. Seasonality does not affect the efficiency of the three fishing gears. Also, there is no significant interaction between seasons and fishing gears (p = 0.525). Computed annual net income and return on investment (ROI) is also greater using EF (PHP 407,630.40/ha/year with 569% ROI) compared to HL and FT (net incomes of PHP 113,244.68/ha/year and PHP 161,618.99/ha/year, and 261% and 309% ROI, respectively). However, the use of EF as a control measure should entail restrictions such that only within rice farm areas and not in open waters and only after harvest or before planting with issued EF licenses and permits from BFAR and local ordinances. Higher penalties should also be imposed for illegal use of EF such as use in open waters. As an alternative to EF, a combination of FT and HL with modifications or more environment-friendly fishing gears can be explored to catch and control the rice eel population.

Vulnerability to Climate Change of “Giant Squid” (Thysanoteuthis rhombus) Fishery in Marinduque, Philippines

The Philippine fisheries sector has been affected by the impacts of climate change. Vulnerability to climate change pertains to a natural system's ability to cope with the negative impacts of climate change, variability, and extremes. Vulnerability Assessment (VA) provides a framework for climate change impacts evaluation over a broad range of systems. Tools such as Fisheries Vulnerability Assessment Tool (Fish Vool) have been developed to do VA. The "giant squid" diamondback (Thysanoteuthis rhombus) fishery in the province of Marinduque is an essential source of food and livelihood in the area. However, its vulnerability to climate change impacts has not been assessed. In this study, the "giant squid" fishery in Gasan, Marinduque, was assessed using Fish Vool. Results revealed that overall climate change vulnerability of the fishery is high, where both sensitivity and adaptive capacity are medium while exposure is high. Overall, the study provided a better understanding of the "giant squid" fishery vis-à-vis climate change and provided information for future fisheries management and conservation in the province.

Stock Assessment of the Blue Swimming Crab Portunus pelagicus (Linnaeus, 1758) in Stock Enhancement Sites of Danajon Bank, Central Philippines

The stock status of Blue Swimming Crab (BSC), Portunus pelagicus, locally known as lambay, in Danajon Bank was assessed from June 2019 to September 2020 to monitor the impact of the BSC stock enhancement initiative by the Philippine Association of Crab Processors, Inc. (PACPI) in collaboration with BFAR 7. The stock was assessed based on the indicators, namely, catch per unit effort (CPUE), exploitation rate (E), average size, length at first maturity (Lm), and Spawning Potential Ratio (SPR). Data analysis was done using FAO-ICLARM Stock Assessment Tools (FiSAT) II software and the Barefoot Ecologist’s Toolbox for the Length-based Spawning Potential Ratio (SPR). Results show that BSC dominated the monitored landings accounting for 66% of the overall catch harvested mainly by crab pot and crab net. Higher CPUEs were obtained in the months of July, June, May and August with annual mean observed to be higher than the previous assessment conducted by ECOFISH in Danajon Bank particularly for crab pot. Population characteristics revealed that male crab grew slightly faster having higher asymptotic length (L∞ =21.65cm Carapace Width or CW) and growth constant (K=1.3yr-1) than female (L∞ =21.40cm CW, K=1.28yr-1). Sex ratio of male to female was at 1:1.28 indicating plenty of female crabs were captured than male. Gravid crabs were abundant in May, December, April and October. Recruitment pattern showed two pulses with primary peak occurred in April and May and secondary pulse happened in August and September. Encouraging performance indicator noted from this assessment was on the bigger probability of capture sizes and mean length of commonly caught BSC falling above the recommended catchable size of 10.2 cm CW pursuant to DA-DILG JAO No. 1 s. 2014. Maturity size (Lm) was estimated at 10.54 cm CW, though smaller than the previous reported Lm values in Danajon but still within the threshold. The estimated SPR was 26%, higher than 20% limit reference point but slightly lower than 27% recorded in the assessment done by ECOFISH Project in 2014 to 2015. The present SPR though lower than 30% precautionary threshold however higher than 21% generated in Visayan Sea Region 7 for the same period. The higher SPR in Danajon Bank compared to Visayan Sea maybe credited to the effect of stock enhancement activity implemented in the area, though observation is not yet conclusive. On the other hand, unfavorable indicators were seen on high exploitation rate (E), high exploitation at yield per recruit some of which already breached the optimum level, consequently subjecting Danajon Bank to high fishing pressure. It is recommended to continue the BSC stock enhancement program of PACPI and BFAR 7 taking consideration some strategies for improvement specified in the recommendations.

Impact of Ecotourism on Local Community’s Participation in Coastal Resource Management: Case of Palaui Island Protected Landscape and Seascape (PIPLS) in Northern Luzon, Philippines

The establishment of marine protected areas (MPAs) managed by the community has been a popular tool for coastal and resource management in the Philippines. As the MPAs limit the use of the resources, the eco-biological components of the marine environment have been preserved and maintained, which opened opportunities for ecotourism activities. Thus, ecotourism has been developed as one way of gaining economic benefits from the coastal and marine resources while conserving biodiversity and restoring critical habitats by shifting resource exploitation from an extractive to a non-extractive usage. This study was conducted using household surveys and key informant interviews to investigate whether ecotourism's development affects the local community's participation and support on MPA management using the case of Palaui Island Protected Landscape and Seascape (PIPLS) in northern Luzon, Philippines. The respondents recognized the impacts of ecotourism on their family welfare, fishing activities, and involvement in MPA management. In particular, ecotourism development strengthens local communities' support for coastal resource management, especially if it provides enough sources of income. The results of this study could provide information to resource managers and policymakers on crafting sustainable ecotourism and alternative livelihood policies in MPAs, taking into account its possible impacts on the coastal fishing communities.

Population Density, Distribution, and Species Composition of Sea Cucumbers in Pagasinan Tidal Flat, Bongao, Tawi-Tawi, Philippines

This study investigated the population density, distribution, and species composition of sea cucumbers in Pagasinan Tidal Flat, Bongao, Tawi-Tawi, Philippines. Sea cucumbers were collected in the night along the tidal flat and by snorkeling along the reef area. The study recorded seven species belonging to genera Holothuria (five species), Bohadschia (one species), and Stichopus (one species). The population densities ranged from 0.09 ± 0.5 to 3.85 ± 1.67 individuals per 100 m2 each with varying habitat preferences.

How Filipino Fishers Use Traditional Knowledge in Identifying Species of Juvenile Mangrove Crabs for Grow-out Culture

Mangrove crab growers in the Philippines still rely on wild-caught late instar to early juvenile mangrove crablets, as supplies from hatcheries are limited. Any batch of crablets caught from the wild is a mix of the three native species under the genus Scylla. Scylla species have different growth rates. Since grow-out culture depends heavily on species' growth, growers should be able to distinguish the species as early as the juvenile stage, which is taxonomically difficult. This study was done to consolidate low-cost traditional identification techniques for juvenile Scylla from fishers of the Philippines for future validation. Focused group discussions were done in fishing communities from Bataan, Pangasinan, and Cagayan on the island of Luzon. The study was continued through online surveys, as travel was restricted due to the Covid-19 pandemic. Results indicate that 70.58% of respondents identify the species of crabs by looking at their claws and 55.88% observe the color of the crabs. Almost half, or 41.17% of respondents, consider the width and size of the carapace. Unique methods in certain Philippine regions include observation of the behavior patterns, carapace texture, rate of weight gain, and seasonality. Validation of the traditional practices identified in this study would result in a reliable "at-a-glance" method of identifying juvenile Scylla in the Philippines, which would shorten the culture period, improve production gains, and manage local populations.