South Sulawesi, Indonesia — PT. Karya Lingkar Hijau (KLH), together with its partners and coastal communities in Laikang Village, has completed a pilot project under the LIF Community Grants – Technology Improving Lives programme supported by the Royal Academy of Engineering, demonstrating a scalable circular aquaculture model with measurable environmental and socio-economic impacts.

The project repurposed nutrient-rich shrimp pond wastewater as a cultivation medium for seaweed, achieving a reduction of nitrogen and phosphorus concentrations by up to 40–55% during the pilot cycle. Seaweed productivity increased by approximately 30% compared to conventional cultivation methods, while reducing dependence on clean seawater inputs.

A total of 33 smallholder seaweed farmers participated in the pilot, with over 40% women farmers actively involved in cultivation, monitoring, and post-harvest handling. Through hands-on training and mentoring, participants improved technical capacity in water quality management, seaweed growth optimisation, and basic business practices. Early market linkage activities enabled participating farmers to access buyers and cooperatives, contributing to an average household income increase of 15–20% during the pilot period.

The project was implemented through a strong community-based approach. Local residents worked collectively to construct pilot facilities, clean cultivation zones, and operate the system, fostering ownership and long-term sustainability. More than 200 cubic metres of shrimp wastewater were treated during the pilot, preventing untreated effluent from entering nearby coastal waters.