University of Guam Community Backyard Aquaponics Systems (CBAS)

Summary

The Community Backyard Aquaponics Systems (CBAS) program is run by the University of Guam Center for Island Sustainability and Sea Grant (UOG CIS & Sea Grant), headed by aquaculture specialist David Crisostomo. Launched with support from the Office of the Governor of Guam, the program directly addresses the island's heavy dependence on imported food by putting working aquaponics systems into residents' backyards. Selected applicants attend mandatory training sessions and workshops on aquaponics principles, system maintenance, and harvesting before qualifying to receive a complete system — individual units are valued at roughly $3,500–$ 10,000 and are provided to qualified recipients at no cost. The first cohort saw its initial installations completed in late 2024, and the program has continued expanding through successive cohorts (a second cohort distributing about 40 additional systems opened in mid-2025, with later cohorts following). Systems typically showcase tilapia and leafy greens such as lettuce in a closed-loop design where fish waste feeds the plants and plants filter the water for the fish. UOG CIS & Sea Grant staff continue to provide technical support after installation to ensure long-term success.

Guiding Principles

Food Sovereignty: CBAS is explicitly framed as a food-security intervention for Guam, where most food is imported. It gives households direct control over production of fresh protein (fish) and vegetables, shortening supply chains and reducing import dependence.
Community Self-Sufficiency: Rather than selling systems, the program transfers both the physical capital (the unit) and the knowledge capital (training plus continuing support) so that families can sustain production themselves across generations.
Circular Economy: Each system is a closed-loop demonstration — fish effluent becomes plant nutrients, and plant roots clean the water returned to the fish — using a fraction of the water of soil-based agriculture.

Learning Outcomes & Transferable Skills

Participants gain practical Food Production skills (raising tilapia, growing lettuce and other produce), applied Water Chemistry literacy (managing the nitrogen cycle in a small recirculating system), and Systems Thinking from operating a coupled biological system. Because cohorts learn together in mandatory workshops, the program also builds Community Organizing capacity and neighborhood knowledge networks, and it strengthens Sustainability Literacy around water conservation and island resilience. These skills transfer directly to small-scale commercial aquaponics, home gardening, and extension-style peer teaching.

How to Replicate or Build On It

Start at the UOG CIS & Sea Grant projects page and the CBAS announcements on seagrant.uog.edu, which describe program rules, training requirements, and cohort registration.
Contact the program lead (aquaculture specialist David Crisostomo, crisostomod8562@triton.uog.edu) for curriculum and system-design details.
The replicable model is: (1) cohort-based application and mandatory hands-on training, (2) provision of a complete, ready-to-run system, (3) structured follow-up technical support. Communities without grant funding can adapt the model with lower-cost DIY media-bed or raft systems while keeping the training-first structure.
Related island-family model: see MALAMA Backyard Aquaponics for Native Hawaiian Families for a culturally grounded counterpart.

Considerations & Constraints

Cost: Systems valued at ~$3,500 (second cohort) up to $7,000–$ 10,000 (first cohort installations) are given free to selected participants, funded via the Office of the Governor; replication elsewhere requires comparable subsidy or cheaper DIY designs.
Skill Level: Beginner-friendly; no prior experience required, but mandatory training attendance is a condition of receiving a system.
Space/Climate: Designed for outdoor backyard installation in Guam's tropical climate; tilapia require warm water, so cold-climate replication needs greenhouse heating or different species.
Tools Required: A complete recirculating aquaponics unit (fish tank, grow beds, pump, aeration); no digital fabrication needed.
Ongoing Maintenance: Daily fish feeding, periodic water-quality checks, pump/aeration upkeep, and plant harvesting — a moderate daily commitment sustained over years.
Access Barriers: Program is limited to Guam residents selected by application; English-language materials; no published open-source build manual or curriculum download was identified.

Prerequisites

None — the program is designed as an entry point. Foundational reading on aquaponics basics (nitrogen cycle, water quality) is provided through the program's own mandatory training.

Primary Source

UOG Center for Island Sustainability & Sea Grant projects page: https://seagrant.uog.edu/projects/