Challenge 03: Sustainably feed the global population
Permanent URI for this collectionhttps://repository.unesco.gov.ph/handle/123456789/22
Ocean Decade
Challenge 03:
Sustainably feed the global population
Generate knowledge, support innovation and develop solutions to optimize the role of the ocean in sustainably nourishing the world’s population under changing environmental, social and climate conditions.
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- Growth, nitrate uptake kinetics, and biofiltration potential of eucheumatoids with different thallus morphologiesNarvarte, Bienson Ceasar V.; Genovia, Tom Gerald T.; Hinaloc, Lourie Ann R.; Roleda, Michael Y. (Wiley, 2021-12-30)The declining production of commercially important eucheumatoids related to serious problems like increasing susceptibility to ice‐ice disease and epiphytism may be ameliorated by nutrition. This ushered to an increasing interest in incorporating seaweeds into an integrated multi‐trophic aquaculture (IMTA) setup to take up excess inorganic nutrients produced by fish farms for their nourishment. In this regard, it is important to understand the nutrient uptake capacity of candidate seaweeds for incorporation in an IMTA system. Here, we examined the growth, nitrate (NO3‐) uptake kinetics and biofiltration potential of Eucheuma denticulatum and three strains of Kappaphycus alvarezii (G‐O2, TR‐C16 and SW‐13) with distinct thallus morphologies. The NO3‐ uptake rates of the samples were determined under a range of NO3‐ concentration (1‐ 48 µM) and uptake rates were fitted to the Michaelis‐Menten saturation equation. Among the examined eucheumatoids, only SW‐13 had a linear response to NO3‐ concentration while other strains had uptake rates that followed the Michaelis‐Menten saturation equation. Eucheuma denticulatum had the lowest Km (9.78 ± 1.48 µM) while G‐O2 had the highest Vmax (307 ± 79.3 µmol · g‐1 · min‐1). The efficiency in NO3‐ uptake (highest Vmax/Km and α) was translated into the highest growth rate (3.41± 0.58 % · d‐1) measured in E. denticulatum. Our study provided evidence that eucheumatoids could potentially take up large amount of NO3‐ and fix CO2 when cultivated proximate to a fish farm as one component of an IMTA system. During a 45‐d cultivation period of eucheumatoids, as much as 370 g NO3‐ can be sequestered by every 1 kg initial biomass E. denticulatum growing at 3% · d‐1. Furthermore, based on our unpublished photosynthetic measurements, the congeneric K. striatus can fix 27.5 g C · kg‐1 DW during a 12‐h daylight period.
- Vulnerability drivers for small pelagics and milkfish aquaculture value chain determined through online participatory approachMacusi, Edison D.; Geronimo, Rollan C.; Santos, Mudjekeewis D. (Elsevier, 2021-11)Climate change impacts on the fisheries can be short-term or long-term, making them highly vulnerable. Fishers' vulnerability encompasses several factors and includes, among others, their sensitivity, exposure to the elements, and their adaptive capacity. The main aim of this study was to help develop a vulnerability assessment tool that can be applied in the various nodes of the fisheries and aquaculture value chains with a long-term view of enhancing the resilience of the fisheries and helping increase the adaptive capacity of the fishing communities. A participatory technique using online workshops was conducted together with various stakeholders (N = 214) who gave insights and suggested indicators that drive climate change impacts and vulnerability. Based on the online workshops conducted, the common hazards/drivers were increasing temperature, typhoons, flooding (sea-level rise), and the recent pandemic, which consequently destroy coral reef ecosystems, affect fisheries yield, increases fish mortality, damage boats, fishing gears, pens, cages, pond dikes, erode beach properties, and devastate houses. In association with these impacts, mobility, travel, processing, and logistic operations are severely reduced. In the human dimension, the fishers and fish farmers are directly affected in terms of income loss, destroyed fishing gears, nutritional deficiencies and health impacts, less fishing operations, early or reduced harvest yield, and low market value of products. In the adaptation options, the infrastructure, social, economic, awareness/knowledge, and relevant governance/policy dimensions are needed to address and help mitigate various climate change impacts.
- Impacts of aquaculture nutrient sources: ammonium uptake of commercially important eucheumatoids depends on phosphate levelsNarvarte, Bienson Ceasar V.; Hinaloc, Lourie Ann R.; Gonzaga, Shienna Mae C.; Roleda, Michael Y. (Springer, 2023-09-14)In an integrated multitrophic aquaculture (IMTA) system, seaweeds serve as extractive species that utilize excess nutrients, thereby reducing the risk of eutrophication and promoting sustainable aquaculture. However, the use of excessive fish feeds and the resultant faecal waste as nutrient streams can contribute to variations in nitrogen and phosphorus levels (e.g., primarily NH4+ and PO4−3) in the surrounding area and this may impact the physiology of the integrated seaweeds, particularly on how these species take up inorganic nutrients. In this study, the effect of different PO4−3 levels on NH4+ uptake of the three commercially important eucheumatoids Kappaphycus alvarezii, Kappaphycus striatus and Eucheuma denticulatum was examined under laboratory conditions. Seaweed thalli (n = 4) were incubated in seawater media containing 30 µM NH4+, and 0, 0.5, 1.0, 1.5, 3.0 or 5.0 µM PO4−3 for 1 h under a saturating light level of 116 ± 7.13 µmol photons m−2 s−1 inside a temperature-controlled laboratory. Species-specific responses to PO4−3 levels were observed. For K. alvarezii, maximum NH4+ uptake (17.8 ± 1.6 µmol gDW−1 h−1) was observed at 0.5 µM PO4−3 and the uptake rate declined at higher PO4−3 levels. For K. striatus, NH4+ uptake increased with increasing PO4−3 levels, with maximum N uptake (6.35 ± 0.9 µmol gDW−1 h−1) observed at 5.0 µM PO4−3. For E. denticulatum, maximum NH4+ uptake (14.6 ± 1.4 µmol gDW−1 h−1) was observed at 1.0 µM PO4−3. Our results suggest that among the three eucheumatoid species, the NH4+ uptake of K. striatus persists even at high levels of PO4−3. However, our results also showed that K. striatus had the lowest range of NH4+ uptake rates. These results should be taken into consideration when incorporating eucheumatoids in the IMTA system, where PO4−3levels significantly vary in space and time.This is contribution no. 500 from the Marine Science Institute, University of the Philippines (UPMSI), Diliman. The AlgaE Team would like to thank the Bolinao Marine Laboratory (BML) for providing the venue to conduct our experiments. BCV Narvarte and MY Roleda acknowledge the Sea6 Energy Pvt. Ltd. for sponsorship during the 24th International Seaweed Symposium (ISS) held on February 19-24, 2023, at Hobart, Tasmania, Australia. Likewise, BCV Narvarte and LAR Hinaloc would like to thank the University of the Philippines- Office of the International Linkages (UP-OIL) for providing them with a travel grant to attend the aforementioned symposium. BCV Narvarte also acknowledges the Department of Science and Technology- Philippine Council for Agriculture, Aquatic, and Natural Resources Research and Development (DOST-PCAARRD) for his PhD Scholarship (GREAT- Graduate Research and Education Assistantship for Technology Program).
- Fisheries Administrative Order No. 267-1: Series of 2023. Rules & regulations governing the landing and transshipping of fish and fishery products that have not been previously landed, and other port services in the Philippines by foreign-flagged fishing vessels.(Department of Agriculture, 2023-12-14)
- Fisheries Administrative Order No. 267: Series of 2021. Rules and regulations governing the landing and transhipping of fish and fishery products that have not been previously landed, and other port services in the Philippines by Foreign-flagged fishing vesssels.(Department of Agriculture, 2021-11-03)
- Transcriptome-derived SNP markers for population assignment of sandfish, Holothuria (Metriatyla) scabraOrdoñez, June F.; Ravago-Gotanco, Rachel (Elsevier, 2024-01-30)The sandfish, Holothuria scabra is a commercially important fishery and aquaculture species contributing to the high-value sea cucumber industry. Overexploited across many areas throughout its distributional range, natural populations are considered in decline. Accurate genetic assignment to population of origin is becoming increasingly important for genetics-based marine fisheries management and monitoring, especially for species experiencing depletion of natural stocks and decline in fisheries productivity due to overfishing and illegal, unreported, and unregulated (IUU) fishing. Initiatives for genetics-based applications on economically important seafood such as H. scabra have been limited by the lack of comprehensive genome or transcriptome resources. The present study developed and evaluated the use of gene-associated single nucleotide polymorphism (SNP) markers to assign sandfish to three locations in the Philippines, in the proximity of existing and emerging hatchery production centers. In silico SNP discovery pipeline using pooled RNA-Seq libraries and medium-throughput genotyping approach generated a dataset comprising 115 individuals genotyped at 88 SNPs. Population assignment using machine-learning analysis and Bayesian approach revealed that the 88 transcriptome-derived SNPs allowed the assignment of sandfish individuals to population of origin, with an overall assignment accuracy of >80%. The novel SNPs developed could find their utility in facilitating the development of geographic traceability tools applicable in the context of sandfish aquaculture, fisheries management and conservation.
- Intact shallow and mesophotic assemblages of large carnivorous reef fishes underscore the importance of large and remote protected areas in the Coral TriangleSalvador, Mikaela L.; Utzurrum, Jean Asuncion T.; Murray, Ryan; Delijero, Kymry; Conales, Segundo F.; Bird, Christopher E.; Gauthier, David T.; Abesamis, Rene A. (Wiley, 2024-02-23)1. Overfishing remains a threat to coral reef fishes worldwide, with large carnivores often disproportionately vulnerable. Marine protected areas (MPAs) can restore fish populations and biodiversity, but their effect has been understudied in mesophotic coral ecosystems (MCEs), particularly in the Coral Triangle. 2. Videos were analysed from baited remote underwater video systems deployed in 2016 to investigate the assemblage structure of large carnivorous fishes at shallow (4–12 m) and mesophotic (45–96 m) depths in two of the largest and most isolated MPAs in the Philippines: an uninhabited, fully no-take MPA enacted in 1988 (Tubbataha Reefs Natural Park) and an archipelagic municipality surrounded by an extensive but not fully no-take MPA declared in 2016 (Cagayancillo). Taxa focused on were groupers (Serranidae), snappers (Lutjanidae), emperors (Lethrinidae), jacks (Carangidae) and the endangered Cheilinus undulatus (Labridae). 3. Mean abundance and species richness were not greater in TRNP than in Cagayancillo regardless of depth despite long-term protection in the former. Limited impacts of fishing in Cagayancillo may explain this result. Differentiation of fish assemblages was evident between TRNP and Cagayancillo but more obvious between depths at each location, probably due more to habitat than MPA effects. In Cagayancillo, overall carnivorous reef fish, grouper and jack mean abundance were 2, 2 and 10 times higher, respectively, at mesophotic depths, suggesting that MCEs can serve as deep refugia from fishing. 4. These findings of differentiation between depths and higher abundance of certain taxa in mesophotic depths emphasize that MCEs are distinct from shallow reefs, serve as important habitat for species susceptible to overfishing and, thus, must be explicitly included in the design of MPAs. This study also highlights the value of maintaining strict protection of MPAs like TRNP for the Coral Triangle and an opportunity to safeguard intact fish assemblages in Cagayancillo by expanding its no-take zones.
- Metamorphic success and production cost of Holothuria scabra reared on microalgae concentrates compared with live microalgaeGarpa, Tomilyn Jan; Caasi, Olivier Josh C.; Juinio–Meñez, Marie Antonette (Bureau of Fisheries and Aquatic Resources, 2024-03-07)The production of live microalgae poses challenges for the expansion of sandfish hatcheries, hindered by high costs and limited technical resources. In relation to this, the use of three imported commercial concentrates (Instant Algae®) - TW1200 (Thalassiosira weisflogii), TISO1800 (Isochrysis sp.), and Shellfish1800 (mixed diatom) - were compared with live Chaetoceros calcitrans (CC). The diet efficacy was evaluated based on larval development, growth, and survival to late auricularia (LA) with hyaline spheres (HS), and the number of post-settled juveniles. Larvae reared with TW did not progress beyond LA, while those fed CC exhibited earlier LA development, larger sizes (1028.43 ± 19.38 µm), and significantly more post–settled juveniles (9,268 ± 2,183.79) compared to SHELL and TISO. Although TISO larvae reached a larger size during LA (855.7 ± 62.67 µm), SHELL resulted in a higher number of post-settled juveniles. The better performance of CC and SHELL may be attributed to their higher carbohydrate content. Despite SHELL and TISO having lower juvenile yields and longer feeding durations, the estimated cost per juvenile using SHELL, TISO, and CC were PHP 2.00, PHP 11.77, and PHP 0.52, respectively. Results showed that microalgae concentrates are not a cost-effective option under the studied conditions. The potential use of microalgae concentrates as supplemental feeds and further research to develop the use of local microalgae concentrates to sandfish larval culture are discussed.This study was funded by Australian Centre for International Agricultural Research (ACIAR) through the project FIS/2016/122 “Increasing technical skills supporting community-based sea cucumber production in Vietnam and the Philippines” and administrative support from the Marine Environment and Resources Foundation (MERF), Inc. We would also like to thank the Bolinao Marine Laboratory of the University of the Philippines Marine Science Institute for the use of facilities and equipment. We are grateful to our collaborators, Jon Altamirano and Roselyn Noran, and SEAFDEC AQD for guidance on the methods used for preparation and protocols of microalgae concentrate feeding regimen. Special thanks to JayR Gorospe for comments on the earlier draft and Jerwin Baure for copyediting this manuscript. The assistance of Mr. Tirso Catbagan in the culture of larvae and maintenance of the experimental tanks was invaluable during the experiment.