World Aquaculture December 2018

54 DECEMBER 2018 • WORLD AQUACULTURE • WWW.WA S.ORG as the rainy season ended, ponds were assessed for water retention, integrity and management was initiated. Abandoned nests were observed and seine sampling validated natural recruitment as fingerlings were collected and subsequently released. The fish pond is designed with a 1.3-mmaximum depth and 30-cm freeboard to facilitate access, limit light penetration and restrict growth of submergent/emergent vegetation. It fills passively during the rainy season; excess water is diverted to the reservoir pond by a channel and concrete gate that control water entry into the fish production pond. During the dry season, water continues to flow into the reservoir pond from the abutting wetland at a low rate (<70 L/min). The reservoir pond is passively filled and maintained at ambient level. Excess water from the reservoir pond overflows a gate and is discharged into a small stream. Water can be transferred from the reservoir pond to the fish pond as needed. The fish pond is repopulated by unharvested or wild fish that enter during the rainy season. A form of polyculture (omnivorous tilapia, benthic catfish, and piscivorous African pike naturally occurs but the presence and abundance of each species is unknown, uncontrolled and problematic. Fish production is enhanced by traditional practices that add vegetation as food, primarily cassava leaves ingested by tilapia, or as fertilizer. Troublesome vegetation is removed manually (Fig. 9). In May 2017, the fish pond was drained, fish harvested, and repairs conducted (i.e., a large tree that fell into the pond was cut and removed, Fig. 7). Pond management and limited training continued during periods when SSU personnel were absent through cell phones and email, with mixed results (Matuha et al . 2016). Liberians have assumed proactive management of the fish and reservoir ponds but more on-site training and guidance are needed. The reservoir pond must be deepened and water management in the fish pond enhanced through acquisition and use of a pump. Traditional fertilization could be improved by using a fermented slurry of vegetative manure that makes nutrients more readily accessible to fish. Liming the fish pond (alkalinity < 20 mg/L) would increase production inexpensively. A dependable supply of fingerlings for stocking is needed to enhance pond management and could be secured through modification and use of nine small, poor-performing rice ponds (range = 300-600 m 2 ; sum = 0.50 ha) located below the fish and reservoir ponds (Fig. 10). Significantly, at least three Liberians that live near GUMM have elected to construct fish ponds. Without access to trained personnel, the ponds were poorly located and constructed (e.g., overflowed during the rainy season, deepest part not near the discharge but rather ringing and adjacent to the pond perimeter). Fish Production in Gbarnga The UMU School of Theology is located in Gbarnga, approximately 200 km northeast of Monrovia and 60 km west of Ganta. While primarily charged with religious instruction, the campus also hosts a pre-school and provides K-12 education and agricultural training. Unlike water-limited GUMM, the School of Theology possesses three natural ponds on-site with an estimated area of 12 ha. Water quality is good, although alkalinity is rather low (< 45 mg/L). Each pond supports a fish population that is actively harvested by local youth (Fig. 11). More training in pond and fish management, modest resources (e.g., boat, hoop nets, holding and hauling capacity), and enhanced security to minimize poaching are needed. Use of simple aquaculture practices such as liming, fertilization, feeding, topping and trapping could dramatically increase production and harvest. Financial self-sufficiency and sustainability would be realized, providing a template/catalyst for people living nearby to pursue aquaculture. Transit to Sinoe and Inspired Youth The College of Agriculture, located at Gbason Town, is the newest UMU campus. It is located in southeastern Liberia, approximately 340 km south of Ganta. Transit from Ganta to Gbason Town requires 10 h on earthen roads only passible during the dry season, if no disruptions are encountered. The location is upcountry and remote, even by Liberian standards. The 200- ha campus dedicates 140 ha to agriculture production and is reminiscent of a self-sufficient ranch. Electricity is available for 1-2 hours at night, provided by a single, small generator. Collected rainwater is used for bathing and other purposes. The nearest cellphone signal and medical service is 1-2 h distant. Students FIGURE 9. Vegetative wastes are placed into fenced areas in the fish pond to decompose and fertilize the pond (upper right of picture). Inability to fill pond above ambient levels promotes growth of emergent vegetation that is removed manually. Photo: Roger Domah. FIGURE 10. Overflow water from the fish and reservoir ponds is discharged through a stream to irrigate rice and other crops. The imaged rice ponds are poor performers and could be modified into broodstock, spawning and nursery ponds. Photo: Thomas Pedulla.