Resource enhancement: Concepts, learnings, and future directions

Fish and fishery products are always in high demand causing pressure on world fish supply. The world’s wild capture fisheries resources ultimately reached its peak around the early 90s and plateaued at around 90 million tonnes. The stagnancy in wild fisheries production poses an alarm to the ever-growing human population. Fortunately, at around the same time, aquaculture production has filled some gap in seafood supply with over 100 million tonnes produced annually. However, there are various concerns about aquaculture and its sustainability. This is where the idea of aquatic resource enhancement comes in, not only to increase fish yield for food but also to compensate for losses caused by anthropogenic interventions, while promoting environmental rehabilitation and conservation. Resource enhancement, as a whole, can include various concepts on sustainable development, habitat conservation and improvement, ecological management, and aquaculturebased stock enhancement. This paper highlights the development of some resource enhancement programs worldwide and provide some examples particularly those from the Southeast Asian Region. We will attempt to tackle some successes and failures, as well as review past and recent experiences to extract important learnings. Based on these lessons, future directions of how resource enhancement initiatives can be made more efficient and sustainable. As a general rule, we recommend that in order to increase chances of success for programs on resource enhancement, it has to be science-based, there needs to be inclusive and participatory planning and management involving all stakeholders and adheres to responsible culture practices. Moreover, there should be concurrent efforts in reducing fishing pressures, as well as in protecting and rehabilitating natural ecosystems

Valuing and Managing the Philippines’ Marine Resources toward a Prosperous Ocean-Based Blue Economy

The ocean-based “blue economy” is a significant part of the Philippine economy that has largely been taken for granted despite its enormous potential. It is of critical importance to a substantial segment of our population dependent on the seas and coastal resources for their livelihood and sustenance, appreciably enlarge the country’s wealth, and significantly contribute to its gross domestic product. This paper attempts to review the major issues concerning marine ecosystems in relation to the country’s pursuit of the blue economy. It discusses the economic and social activities in relation to the seas and coastal areas, and provides updated estimates of the real value of the country’s marine ecosystems’ goods and services. Based on primary and available secondary data, the marine ecosystems (excluding the continental shelf) can contribute a conservative monetary value of US$ 966.6 billion to the economy. In light of the risks and threats to the blue economy, the paper further discusses the country’s current national initiatives and involvement in regional collaborations toward ensuring its health and sustainable development. Given the Philippines’ vast largely untapped potential, a recommendation for the creation of a Department of Marine Resources, separate from the Department of Agriculture, seems in order

Role of resource specialists in community-based coastal resources management in Bolinao, Pangasinan

In ARCHIV 115463 v.

Effects of sediment enrichment with macroalgae, Sargassum spp., on the behavior, growth, and survival of juvenile sandfish, Holothuria scabra

To scale-up culture production of the sea cucumber Holothuria scabra using ocean grow-out systems, bottlenecks in enhancing the growth and survival of juveniles need to be addressed. As the selection of release sites is fraught with uncertainty, organic enrichment of sediment using dried Sargassum spp. to increase food abundance (i.e., microalgae and bacteria) may be a viable option to optimize ocean nursery systems. The effects of sediment enriched with dried Sargassum spp. on the diel burying behavior, growth, and survival of juvenile (>3 g) sandfish were investigated in the field for 60 days using sea pens (2.25 m2) with a stocking biomass of 66 g m−2, and in glass tanks (0.045 m2) with the same stocking biomass (∼3 g individual tank-1) in the laboratory for 30 days. Enrichment with Sargassum markedly changed sediment characteristics. Although diurnal burying behavior did not vary significantly between treatments, a greater percentage of juveniles in enriched pens and tanks remained buried during the daytime compared to unenriched pens. Without protection from predators in the wild, all juveniles from enriched pens survived compared to those from unenriched pens (85 ± 10%) after 7 days. After 30 days, absolute growth rates (AGR) of juveniles in enriched pens (0.51 ± 0.06 g day-1) and tanks (0.82 ± 0.27 g day-1) were significantly higher compared to unenriched pens (0.13 ± 0.04 g day-1) and tanks (0.49 ± 0.19 g day-1). Results showed that mean sediment chlorophyll-a content of ∼4 μg g-1 in sea pens enriched with Sargassum spp. could hasten the growth of ∼3 g juveniles to >20 g in 30 days. This study demonstrated that the organic enrichment of sediment is a viable option to optimize the growth of sandfish in an advanced ocean nursery system that may significantly improve survival prior to release for grow-out. Keywords: Holothuria scabra, Behavior, Growth, Survival, Sargassum, Sediment enrichmen

Milkfish (Chanos chanos) Fry Concession System in Bolinao, Pangasinan: Implications to Coastal Resources Management

The ecological and socioeconomic implications of the concession system on milkfish (Chanos chanos Forssk.) fry in Bolinao, Pangasinan were evaluated from 1996 to 1999. Monitoring of landed catch from 1996 to 1998 showed that the seasonal trend and annual volume of catch varied widely during the three-year period. The fry season in 1996 and 1997 lasted seven months, starting from the second week of April to the second week of October. However, during the 1998 season, fry were available for eight months starting in the second week of March and ending in November. The peak period also varied considerably during the three-year period. In 1996, peak abundance of fry was observed in the last week of July while in 1997 and 1998, the peak was during the second week of May. The volume of total catch for the entire season also varied widely, from as low as ~400,000 fry (1997) to as high as 2,400,000 fry (1996). The concessionaire “postor” has the sole right to buy all fry caught within the municipal waters. Thus, s/he dictates the buying price. Moreover, the existing concession system has no mechanism to regulate harvest of milkfish fry gathering. This arrangement allows the concessionaire to enjoy huge economic benefits while the fry gatherers only get a minimal share in the income. To promote sustainable and equitable harvest of milkfish fry, a new access arrangement through a permit system was proposed by the fry gatherers. The proposed permit system will promote a sustainable harvest of milkfish fry through the implementation of a closed period during the fry season. Compared to the present concession system, the permit system is believed to be more equitable because of the abolition of the 1/3 cut levied by the concessionaire on the landed catch. The permit system also facilitates a mechanism that provides for transparency on the selling/buying price. More importantly, fry gatherers will have the opportunity to sell to buyers offering a relatively higher buying price. In addition, fry gatherers may also opt to grow out milkfish fry to fingerlings which may potentially give them higher economic returns for their catch

Viability of a bottom-set tray ocean nursery system for Holothuria scabra Jaeger 1833

Scaling up the hatchery production of juvenile sandfish Holothuria scabra is constrained by limited hatchery space and the associated high operational costs. To shorten the hatchery rearing phase, ocean nursery systems like floating hapa nets have been used with good prospects but with limitations during rough sea conditions. In this study, the potential of bottom‐set trays (0.14 m2) as an alternative ocean nursery system for early sandfish juveniles (0.5 ± 0.1 cm) was evaluated. The effects of stocking density and presence of artificial substrates (AS) on the growth and survival were determined in a 60‐day field experiment. Average length and growth rates at lower stocking density treatment (100 individuals tray-1) were significantly higher (1.45 ± 0.22 cm; 0.03 ± 0.01 cm day-1) than at higher stocking density treatments (400 and 500 individuals tray-1) 0.95 ± 0.06 cm; 0.03 ± 0.004 cm day-1) with or without AS (p < .05) respectively. The coefficient of variation in length (CV) at high stocking densities were significantly higher than at low densities (p < .05) and growth rate was strongly negatively correlated with density. Survival was significantly higher (55% ± 9%) in trays with AS across all stocking density treatments than in trays without AS (34% ± 2%). Results suggest that AS may have reduced intra‐ and interspecific interactions, resulting to significantly lower growth variations and higher survival. The bottom‐set tray with AS can be a practical alternative ocean nursery unit for rearing early sandfish juveniles particularly when the sea surface condition is rough. With improved design and density management, survival and growth may be further enhanced.This work was part of the research project of MAJM funded by the Department of Science and Technology—Philippine Council for Agriculture and Natural Resources Research and Development (DOST-PCAARRD)

Enhancement Effect of Sea Urchin Grow-out Cages in Lucero, Bolinao, Pangasinan

A preliminary study was conducted on the environmental impact of sea urchin (Tripneustes gratilla Linnaeas) grow-out culture in Lucero, Bolinao, Pangasinan. It was hypothesized that the feces generated by the caged urchins (~6,000 individuals at any one time) might cause localised sediment organic enrichment and subsequent shifts in benthic faunal communities. Results from preliminary surveys conducted in April and August of 1999 indicated minimal impact of sea urchin grow-out culture on the local reef flat community. Some enhancement of faunal abundance and sediment organic matter content in the cage area were noted; however, the impact was limited to a radius of 5-25 meters from the grow-out cages. The enhancement effects appeared to be seasonal occurrences that were dependent on local currents and degree of wave exposure. Epiphyte biomass, total suspended solids, sediment grain size, and relative water movement seemed largely unaffected by sea urchin grow-out culture. However, more frequent and thorough samplings are needed to validate these initial results. The presence of localised enrichment in sediment organic content and epibenthic faunal density suggest the possibility of converting the sea urchin grow-out area into polyculture systems that would make more efficient use of the food resources available while minimizing potential anthropogenic impacts on the environment

Establishment and Implementation of the Balingasay Marine Protected Area: A Community-Based Approach

A community-based approach in the establishment and implementation of a marine protected area (MPA) in Balingasay, Bolinao, Pangasinan is presented. The factors necessary to facilitate the successful establishment and implementation of a community-managed MPA include heightening of environmental awareness, community mobilization, and legal/institutional and financial assistance. A heightened environmental awareness encouraged the community to undertake resource management action. The formation of a people’s organization, SAMMABAL (Samahan ng mga Mangingisda at Mamamayan ng Balingasay), was crucial in assessing environmental problems (e.g., overfishing) and identifying the establishment of an MPA as a management tool to address the problem. SAMMABAL was also instrumental in eliciting community support for the issuance of a municipal ordinance in the establishment of the MPA. Subsequently, the organization initiated the patrolling of the MPA. Institutions involved in the community-based management of the MPA also included the multi-sectoral council (BRMC – Balingasay Resource Management Council) and representatives from the barangay council and the municipal government. This institutional arrangement has proven to be very resilient, indicating a high probability of sustaining its successes despite some obstacles and shortcomings. Clear delineation of the role and functions of the institutions and the stakeholders was essential in advancing the initiative. This case study will draw on the lessons from the experience of a four-year community-managed MPA

Assessment of the sea cucumber resource and fishery in the Bolinao-Anda reef system

Fishery-independent and -dependent surveys were conducted to assess the status of the sea cucumber resource and fishery in Bolinao and Anda, Pangasinan. Thirty-five species of holothurians were recorded in 25 sampling stations within seagrass beds, coral reefs and mixed habitats. The estimated total population density of all aspidochirote sea cucumber species is 63 ind. ha-1. The artisanal multi-species fishery is at present primarily based on Holothuria scabra, Stichopus horrens and Bohadschia marmorata although there are indications that other high-value species were fished to local extinction. Taken together, the small sizes (<20 cm body length) of the majority of aspidochirote sea cucumbers, their low population densities, and the continuous decrease in catches are clear signs of an overexploited fishery that will likely collapse without management intervention. Adaptive management strategies for Bolinao and Anda are recommended based on the findings of this survey

Pseudocryptic diversity and species boundaries in the sea cucumber Stichopus cf. horrens (Echinodermata: Stichopodidae) revealed by mitochondrial and microsatellite markers

Abstract Morphologically cryptic and pseudo-cryptic species pose a challenge to taxonomic identification and assessments of species diversity and distributions. Such is the case for the sea cucumber Stichopus horrens, commonly confused with Stichopus monotuberculatus. Here, we used mitochondrial cytochrome oxidase subunit I (COI) and microsatellite markers to examine genetic diversity in Stichopus cf. horrens throughout the Philippine archipelago, to aid species identification and clarify species boundaries. Phylogenetic analysis reveals two recently diverged COI lineages (Clade A and Clade B; c. 1.35–2.54 Mya) corresponding to sequence records for specimens identified as S. monotuberculatus and S. horrens, respectively. Microsatellite markers reveal two significantly differentiated genotype clusters broadly concordant with COI lineages (Cluster 1, Cluster 2). A small proportion of individuals were identified as later-generation hybrids indicating limited contemporary gene flow between genotype clusters, thus confirming species boundaries. Morphological differences in papillae distribution and form are observed for the two species, however tack-like spicules from the dorsal papillae are not a reliable diagnostic character. An additional putative cryptic species was detected within Clade B-Cluster 2 specimens warranting further examination. We propose that these lineages revealed by COI and genotype data be referred to as Stichopus cf. horrens species complex