38 MARCH 2026 • WORLD AQUACULTURE • WWW.WAS.ORG long-lasting materials such as galvanized iron, polyvinyl chloride, or virgin-grade high-density polyethylene for pontoons or runners, as these ensure structural integrity during storms and flood events. Bamboo frames should be avoided due to their poor strength and low longevity under turbulent conditions. Small-mesh netting is recommended to prevent the escape of juveniles (FAO, n.d.; NFDB, 2016). Over-top netting should also be installed as an added layer of containment to prevent fish from jumping or being displaced by predators or strong winds. To further reduce escape risks during extreme weather, flood-overflow baffles or reinforced barriers should be integrated into the pen design (FAO, n.d.; NFDB, 2016). Operational biosecurity measures include the use of dedicated harvest socks or totes during fish handling to minimize accidental releases, as well as quarantining broodstock for at least seven days prior to stocking to ensure only healthy individuals enter culture systems (FAO, n.d.). Daily pen integrity inspections must be logged, and an escape or incident reporting system should be in place to enable early detection and rapid response in case of breaches. Finally, comprehensive record-keeping for stocking, transfers, and harvests ensures accountability and traceability, which are critical for biosecurity management in open-water aquaculture (NFDB, 2016; FAO, n.d.). We recommend confirming BFAR/LLDA permitting for any culture, transport, or processing of invasive ornamentals, and clarifying whether special authorization is required for Flowerhorn penning. Coexistence and Population Expansion of Invasive Cichlids Field observations and local reports indicate that Flowerhorns (Amphilophus hybrids) and Jaguar cichlids (Parachromis managuensis) are both present and thriving in Lake Sampaloc (Figure 8). While Jaguars are described as an aggressive piscivorous species (Dadiono and Murti, 2023), the continued presence of robust Flowerhorn populations based on local observation suggests these hybrids remain well established. This observation depicts their apparent resilience and adaptability, though it does not establish a causal relationship regarding interspecific competition or coexistence mechanisms. A rapid creel and shoreline transect (n≈20 interviews; 10 transects) would establish relative encounter rates of Flowerhorn vs. Jaguar within one season. Both species are frequently caught by the fishing community and are commonly observed in shallow, vegetated zones around the lake’s periphery (Figure 9). These habitats provide abundant resources and potential breeding sites, which may contribute to the observed overlap in their distribution. Similar to Flowerhorns, Jaguar cichlids are also harvested by visiting fisher-folk for consumption. However, their dominance has severe implications for native biodiversity. The native Ayungin (Leiopotherapon plumbeus) (Figure 10), once a common catch for local fishers, is now rarely encountered and has been classified as endangered by the IUCN (2023). The aggressive spread of multiple invasive species reflects their ecological plasticity and poses a compounded threat to the lake’s native fish populations, accelerating the decline of this ecologically and economically important species. Aquaculture Management and Community Engagement Community education and aquaculture management are pivotal for addressing Lake Sampaloc’s ecological challenges. Encouraging responsible cage culture, such as wildlife-proof designs, can help prevent further accidental introductions of invasive Flowerhorn cichlids. The lakeside community in Barangay IV-A practices intensive tilapia (Oreochromis spp.) farming. Runoff from these fish pens, rich in nutrients and potential chemical residues, contributes to eutrophication, algal blooms, and overall water quality degradation (Figure 11). While such conditions significantly stress sensitive native species like Ayungin, Flowerhorns continue to thrive. Their remarkable phenotypic plasticity and resilience enable them to survive and even dominate in polluted or altered habitats, stressing the urgent need for integrated aquaculture and invasive species management (Nasution et al., 2022). Successful community-based environmental monitoring initiatives, such as the Coastal Resource Management (CRM) Project in Apo Island, illustrate the effectiveness of engaging fisher-folk in ecological monitoring, fisheries law enforcement, and participatory FIGURE 7. Recreational fishing by visiting Laguna locals demonstrates human interaction with the lake ecosystem and opportunistic harvesting of Midas cichlid hybrids. Photo: H.N. Gasmen. FIGURE 8. Jaguar cichlid (Parachromis managuensis) collected by visiting fisher-folk for consumption. Photo: H.N. Gasmen.
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