Asian-Pacific Aquaculture 2024

July 2 - 5, 2024

Surabaya, Indonesia

INTEGRATIVE SANDFISH CULTURE SYSTEMS: CHALLENGES AND LESSONS LEARNED ON THE PILOT TRIALS IN BOLINAO, PANGASINAN, PHILIPPINES

Julie Clarice R. Salva*, Tomilyn Jan S. Garpa, Garry R. Bucol, and

Marie Antonette Juinio-Meñez

 

The Marine Science Institute

University of the Philippines Diliman

Diliman, Quezon City, 1101

jrsalva@up.edu.ph

 



Holothuria scabra, also known as sandfish, is a deposit-feeding sea cucumber. It has the remarkable ability to ingest particulate waste excreted by other organisms, making it an excellent candidate for Integrated Multi-Trophic Aquaculture (IMTA). Growth of sandfish in the pilot trials with other low trophic species (i.e. sea urchins, green mussels, and siganids) demonstrated positive prospects for implementation in three sites (Victory, Silaki, and Rongos) in Bolinao, Pangasinan. However, the four integrative culture systems each presented novel challenges that required swift interventions and urged the need for design modifications necessary for scaling-up. Strong wave exposure and high influx of freshwater during the rainy season are among the external forces that have jeopardized the structures and survival of the animals in certain sites. While all pilot sites are suitable for sandfish culture based on established indicators (i.e. sediment grain size, penetrability, seagrass cover), some sites are not suitable during the typhoon season. Stocking time, stronger culture structures, and culture phase (i.e. nursery or grow-out) are essential to mitigate setbacks in the production process. Environmental conditions optimal to source and stock wild juveniles of the other species are also important. The sheltered location of Rongos constrained natural mussel spatfall which required the relocation of the nylon ropes in a different area within the channel. The free-ranging siganids in multi-culture systems were difficult to monitor and required refinements in pen design with the addition of an inner net to confine these finfishes and allow supplemental feeding of seaweeds to improve growth. Despite these challenges, the harvest of sea urchins and mussels in the respective sites demonstrated the feasibility of these integrative culture systems to supplement the income of coastal households. Recognizing and addressing these opportunities and challenges are vital in optimizing operational strategies for the adoption and expansion of these sustainable sandfish IMTA systems. Further assessment on the viability of these culture systems from social and ecological perspectives aside from income generation are likewise essential.