Adi Barocas  Carnivore ecology in dynamic landscapes  

The Peru Giant Otter Conservation Program is dedicated to understanding and conserving the endangered giant otter and the vital freshwater ecosystems the species inhabits in the Amazon basin. A core objective is to investigate the ecological role of top predators like the giant otter and black caiman in regulating prey populations and influencing the productivity and functionality of shallow lake ecosystems. The program also aims to assess the impacts of human activities, particularly artisanal small-scale gold mining (ASGM) and fishing, on these sensitive environments and their biodiversity. Through long-term monitoring, the program seeks to elucidate the drivers of ecosystem health, inform adaptive management strategies, and ultimately benefit local human communities who depend on the ecosystem services provided by these freshwater bodies.

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Over years of extensive research, the program has shown significant achievements. It has demonstrated that giant otter populations persist in degraded areas, even showing recovery potential, although their occurrence and group sizes are notably reduced and more variable in unprotected areas affected by extractive activities. Key findings highlight the strong positive association between otter presence and abundance with good water quality, particularly higher dissolved oxygen levels and transparency. Research has also revealed that ASGM activities significantly impact the prey base, leading to trophic downgrading in unprotected lakes, where carnivorous fish assemblages are depleted and detritivores become dominant, contrasting with the carnivore-dominated communities in protected areas. Furthermore, the program has shown that protected areas effectively maintain higher biodiversity of freshwater birds, especially aquatic specialists. Studies on mercury contamination in fish have directly linked elevated levels to local mining intensity, underscoring risks for both top carnivores like otters and human populations. Interestingly, giant otters in mined areas have shown behavioral adaptations, including increased avoidance of human presence in heavily disturbed areas, but also a surprising tendency to occur near deforested mining scars in less impacted lakes, suggesting a capacity to recolonize restored areas.

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Current and future directions for the program involve a comprehensive, multi-scale approach to further investigate these complex ecological dynamics. This includes detailed mapping of lake bottoms using Unmanned Surface Vehicles (IUVs) to assess habitat complexity, and enhanced monitoring of top predator (giant otter and black caiman) abundance and space use through visual surveys and GPS tagging. These efforts will inform the selection of specific study quadrates within lakes to quantify the biodiversity of zooplankton and phytoplankton, crucial indicators of ecosystem health. The program will also precisely measure water quality, nutrient availability, and photosynthetic rates to assess overall ecosystem functionality. By integrating these extensive datasets with statistical and structural equation models, the program aims to disentangle the relative impacts of habitat degradation and predator dynamics on ecosystem productivity and integrity, ultimately providing critical scientific backing for effective conservation and restoration strategies in the Amazon's vulnerable freshwater environments.​

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This project is led by Tel-Hai Academic College and MIGAL - Galilee Research Institute, in collaboration with the San Diego Zoo Wildlife Alliance and CINCIA.