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1. “FARMING OF Halymenia durvillei (BUWAK-SAANG) IN DIFFERENT DEPTHS USING FIXED BAMBOO FLOATING RAFT VERTICULTURE METHOD” by: Jacalan , Jonathan T. Poyos , Joshua Ken C. Abayon, Remart H. Gingco , Raymond R. Damiles , Rino G. Adviser & Co-Adviser: Mr. Jaylord Estil and Dr. Anthony S. Ilano April 21, 2025

2. Chapter 1:Introduction The Philippines ranks 4 th globally as the largest producer of seaweeds ( FAO, 2022) . These species are consumed directly as food by Filipinos and utilized in their industrial form (carrageenan). Kappaphycus alvarezii / K. striatum ( cottonii ) and Eucheuma denticulatum ( spinosum ) are the main species cultured by seaweed farmers and utilized for the production of carrageenan in the country (Ask et al., 2002). The Philippines is endowed with 1,065 seaweed species, and 350 of which have known economic values ( Lastimoso et al., 2021). Halymenia durvillei (Bory de Saint-Vincent, 1828) ( buwak-saang ), which serves as food for many Filipinos and has high-value pigments (US$ 1,030/mg r-phycoerythrin) (Bermejo et al. 2002; Spolaore 2006), as well as alternative carrageenan (US$ 114.79/5g lambda-carrageenan) ( Fenoradosoa et al. 2009). In terms of cultivation, Halymenia durvillei lacks optimized farming methods and is harvested naturally from the wild ( Plentex , 2025). Existing studies of this species focus only on ex-situ innovative cultivation on light-water-density optimization (Rula et al., 2021) and vegetative propagation (Trono et al., 2019). Research has shown that cultivation of this species is important and can be improved by providing an applicable open water farming method related to optimizing its growth depth, improving its growth and survival, through conducting a verticulture farming of Halymenia durvillei using a floating fixed bamboo raft inserted with net bags at different depth levels. Rationale of the Study

3. Chapter 1:Introduction Objectives of the study The general objective of this study is to conduct a verticulture farming of Halymenia durvillei in Bantigue, Luyang , Marine Sanctuary Carmen, Cebu, using a fixed floating bamboo raft inserted with net bags at different depth levels. This study specifically aims to: 1. Measure the growth rate and yield of H. durvillei cultivated on fixed floating bamboo rafts inserted with net bags at varying depth levels (1m, 3m, and 5m) within the marine sanctuary in Bantigue, Luyang , Carmen, Cebu. 2. Determine the water physicochemical parameters, which include: current, salinity, temperature, pH, and dissolved oxygen in the culture area relative to the growth and sustainability of the seaweed. 3. Determine the optimal growth depth of H. durville i cultivated in verticulture method at three sampling depths specifically at 1m, 3m, and 5m.

4. Significance of the study This study will give an idea and benefits for the following: Seaweed farmer and Local governments/ communities Seaweed farmers can benefit from alternative sources of carrageenan and species for cultivation. Local communities and governments receive data to create new livelihoods and promote resource sustainability. Entrepreneurs, Students, and Future Researchers Entrepreneurs can explore new business avenues due to the economic and nutritional value of H. durvillei , while students and future researchers gain reference material and educational resources for further studies in marine science and aquaculture. Scopes and Limitations The study focuses on field trials that will be conducted in Bantigue Luyang Marine Sanctuary, Carmen, Cebu. Focusing on the growth and survival of H. durvillei using a 3x3m bamboo raft with net bags at three depths (1m, 3m, 5m). It includes three 30-day culture trials, each with one stocking density (100g per net bag), and measures selected physicochemical parameters (Temperature, salinity, dissolved oxygen, current, and pH) every 7 days. Only one site, one density, five water parameters, and three depth treatments are used, limiting generalizability and excluding broader geographic or seasonal variations.

5. Innovative Cultivation of H. durvillei Trono, (2010). “A Primer on the Land-based Culture of H. durvillei ”, methodology relies on vegetative propagules sourced from wild stocks, the 40 tanks have been seeded with cuttings, and biomass yields are projected to reach up to 40 kilograms within an 8-10 week cropping period. His work demonstrates the viability of propagule-based farming. Rula et al., (2021). “Influence of Light, Water M otion, and Stocking D ensity on the growth and pigment content of Halymenia durvillei (Rhodophyceae) under laboratory conditions”. The result of their study shows that the highest growth rates and phycobiliprotein yields occurred under full light (100%), moderate water motion, and the lowest stocking density (50 g) . Disputes O ver Optimal Stocking Density and Cultivation Method Herliany et al., (2016). Debates on optimal stocking density persist. He argues that wider spacing—and thus lower crowding—enhances wet weight and relative growth. Aslan, (1998); Hendri et al., (2017); Hendri et al., (2018). They stated that the long line, floating raft, and off-bottom methods have advantages but also have shortcomings: the long line method requires extensive spatial areas that disrupt waterborne traffic, suffers structural vulnerability to wave/current damage to thalli, and incurs high maintenance costs with pest/grazer susceptibility; the floating raft method has elevated production costs, grazer infestations, and structural damage from currents/waves; while the off-bottom method struggles with sediment accumulation smothering crops and pest outbreaks due to environmental exposure. Chapter 2: Review of Related Literature and Studies

6. Yahya et al., (2024). “ Comparison of two cultivation methods for domesticating wild red algal eucheumatoids for use in the seaweed industry”. The results show that the tie-tie method recorded a better growth rate, allowed more space for them to grow, but are prone to detachment and are more vulnerable to grazing. While, the basket net method has a better survival rate; the growth was more restricted due to less space within the basket net, but the loss of biomass from grazing and complete loss from detachment was prevented. Effectiveness of Verticulture Method Hendri et al., (2018). “ Intensification of seaweed cultivation Euchema cottonii with verticulture method in the water of Kelagian Island, Lampung Bay” . In their study, verticulture method with net bag shows effectiveness and provide high productivity of eucheumatoids . He also s tated that this method is easy to control, and yield higher production volumes, as well as being more resistant to pest and grazers attacks than the other methods commonly used. Optimal Water Parameters for Seaweed Cultivation Kayaalp et al., (2016). The environmental stressors, such as changes in temperature and salinity, may limit the H. durvillei species’ bioactive potential in certain marine conditions. Ullah et al., (2025). The optimal salinity may vary by species; for instance, Gracilaria tenuistipitata thrived at 14.75 ppt, while Eucheuma cottonii was cultivated successfully at 31.33-32.33 ppt. Wahidah et al., (2022). T he optimal temperature for seaweed is typically ranges from 28.1 to 28.9°C, with pH levels between 6.3 and 7, which are conducive for growth.

7. Figure 1 . Map showing the research site in Bantigue Luyang Marine Sanctuary, Carmen, Cebu. The field culture will be conducted in Bantigue, Luyang Marine Sanctuary, Carmen, Cebu (10° 36' 57.9384'' N124° 1' 38.8884'' E). The cultivation setup is planned to be approximately 200 meters away from the coast. The depth at the cultivation site will be measured using a depth sounder during the lowest low tide. The selected site will be carefully chosen based on the water quality, such as current, salinity, pH, dissolved oxygen, and depth, all of which are critical for the successful growth of H. durvillei . Study Site S1= Trial 1 S2= Trial 2 S3= Trial 3 Chapter 3: Materials and Methods

8. Materials and Equipment The H. durvillei seedlings will be collected from the Pandong Bato Marine Sanctuary in Puente, Carmen, Cebu. The area where the seedlings that will be collected should be free from the source of pollution. The seedlings should be in healthy condition and will be placed in a mesh basket with banana leaves to avoid dehydration before cultivation. Figure 2 . Halymenia durvillei Bory de Saint-Vincent, (1828). https://marinebiodiversity.org.bd/species/halymenia-durvillei/ Sample Collection Table 1. List of the materials that will be used in the cultivation of Halymenia durvillei . Materials Quantity Size Healthy H. durvillei thallus 15 pcs. 100g each Bamboo 10 pcs 3m each Polyethylene rope 9 pcs 6m each (#3) Floaters (gallons) 12 pcs medium Nylons 2 packs 2 mm Net bag 15 pcs 25 cm (mesh size: 1.5cm) Sinker (rocks) 5 pcs   Anchor (cement) 4 pcs   Digital weighing scale 1 unit   pH meter 1 unit   Refractometer 1 unit   DO meter 1 unit   Thermometer 1 unit   Surface drogue 1 unit   Depth sounder 1 unit

9. Experimental Design This research will be using a verticulture method that is applied by the study of Hendri et al., (2018). This research will be conducted in 3 culture trials , each lasting 30 days (equivalent to 1 month). Each trial will consist of 3 treatments using a combination of 3 depth levels (1m, 3m, and 5m). Each treatment contains 5 replicates (15 total), and 100g of H. durvillei seedlings will be stock in each treatment for each trial . Figure 4 . Net bag with 25 cm diameter, 25 cm long , and 1.5cm net mesh size. Figure 3 . Construction of 3m x 3m fixed bamboo raft that will be used for H. durvillei cultivation through verticulture with specific depths. (a) planting spot, (b) floaters, (c) sinkers, (T1) treatment 1, (T2) treatment 2, (T3) treatment 3

10. Statistical Treatment The method that will be used in this study is quantitative. According to Creswell (1994), it is an inquiry that tests theories by examining relationships between variables, using numerical data and statistical analysis to determine if a theory's predictions hold. The quantitative method will be appropriate in this study since the study will focus on statistical and experimental analysis through determining the optimal growth depth of H. durvillei by calculating its growth increment, growth rate, and survival analysis of this species after cultivation. W ater parameters will be collected every 7 days in each trial (30 days). Growth increment, growth rate, and survival rate (number of survivors) will be measured after cultivation of each trial. Data processing and analysis method Growth increment of the cultured seaweed in each treatment of the three trials will be measured using this equation: Growth increment= Wt - WIn Where Wt and WIn are the final and initial weights in grams (g), respectively. Growth Rate (Dawes et al., 1993) of the cultured seaweed in each treatment of the three trials will be measured using this equation:   Survival Rate (Karim, 2007) of the seaweed in each treatment of the three trials will be measured using this equation: Where Nt = the number of individuals in sampling days and No= are the number of initial number of individuals in (%), respectively.   Types of data that will be collected:

11. References Bory de Saint-Vincent, J. B. G. M. (1828). Cryptogamie . In L. I. Duperrey (Ed.), Voyage autour du monde, exécuté par ordre du Roi, sur la corvette de S.M. la Coquille, pendant les années 1822, 1823, 1824 et Hendri, M., Rozirwan , R., Apri , R., & Handayani , Y. (2018). Intensification of seaweed cultivation Euchema cottonii with the verticulture method in the water of Kelagian Island, Lampung Bay. International Journal of Marine Science, 8. Rula, Najeen Arabelle & Ganzon-Fortes, Edna & Pante, Ma & Trono, Gavino. (2021). Influence of light, water motion, and stocking density on the growth and pigment content of Halymenia durvillei (Rhodophyceae) under laboratory conditions. Journal of Applied Phycology. 33. 10.1007/s10811-021-02474-4. Trono Jr, G. C. (1999). Diversity of the seaweed flora of the Philippines and its utilization.  Hydrobiologia ,  398 , 1-6. Trono Jr, G. C. (2010). A primer on the land-based culture of Halymenia durvillaei Bory de Saint-Vincent (Rhodophyta).  Marine Science Institute, University of the Philippines Diliman: Quezon City, Philippines .

12. Budgetary Requirements Materials Quantity Needed Mass (kg) Metric length (eg. mm, m) Budget Bamboo pile 20   3m each 1,000 php Polyethylene rope 18   200m 300 php PE nylon   4kg   2,000 php HDPE medium gallon 24     720 php PE net 30   30m (1m each bag) 4,500 php Anchor (cement) 8 160kg (4 sack)   1,000 php Halymenia durvillei seedlings 30 3kg (100g each)   165 php Total       9, 685 php Other expenses Purpose Quantity Budget Gasoline Motorcycle fuel and boat fuel 40 liters 2, 800 php Labor for boat driver For installation of cage, for site selection, for transportation.   2, 400 php Total     5, 200 php Table 1. Budgetary requirements for the materials that will be used in the construction of 2 fixed bamboo floating raft ( verticulture ).   Table 2. Budgetary for other expenses in this research study.

13. Timeline Submission of the permission letter will be conducted in April (week 2) Preparation of materials and net bag construction will be conducted from April (week 3) to May (week 2) Planting site and cultivation method testing will be conducted in June (week 1) Construction of 2 bamboo rafts will be conducted from June (week 4) and July (week 1) Trial 1 execution will be conducted in August (week 1 to week 4 ) Trial 2 execution will be conducted from August (week 2) to September (week 2) Trial 3 execution will be conducted from August (week 3)to September (week 4) Data collection and analysis will be from October (week 1) to (week 4) Write-up of research paper will be from October (week 4) to November (week 4) Submission of publication will be from January (week 1 to 4) Submission of the examination will be from January (week 1 to 4)

14. THANK YOU AND GOD BLESS!