Successful reintroduction of captive-born Neotropical otters in Brazil

On June 4, 2025, Instituto Ekko Brasil released two captive-born Neotropical otters into Peri Lagoon on Santa Catarina Island. This event represents the first fully documented reintroduction of captive-born individuals into a wild population that has been in decline for several decades. The otters, named Nanã and Lucky, were raised through a managed breeding program to serve as pioneers in a structured effort to stabilize the local population. A case study detailing the project has been published in the journal Estuarine Management and Technologies, offering a potential framework for similar conservation work across Latin America.

The Neotropical otter, or Lontra longicaudis, is a semi-aquatic apex predator currently classified as Near Threatened by the International Union for Conservation of Nature. These animals are essential to the health of rivers, lakes, and coastal areas, and their presence generally indicates clean water, intact vegetation, and a healthy supply of prey. However, their numbers have dropped significantly due to various pressures. Habitat fragmentation caused by urbanization, agricultural runoff, and illegal hunting have all contributed to their precarious status, with human activities often worsening localized population declines.

This reintroduction was developed in response to troubling mortality rates observed in Peri Lagoon. Researchers monitoring the area over a thirty-six-year period documented a consistent downward trend in the otter population, including at least four deaths in 2018 alone. While the lagoon still retains ecological value with its protected coastlines and active burrows, it has faced ongoing challenges from pollution and habitat degradation. The breeding program at Instituto Ekko Brasil was established to address this, successfully producing fifteen cubs between 2016 and 2022. The goal was to prepare these otters for a safe return to their natural habitat while avoiding the risks of human imprinting or genetic mismatches.

The successful release of these otters is expected to have a wider impact on the Peri Lagoon ecosystem. By restoring the otter population, researchers aim to improve overall biodiversity and ecosystem health. As apex predators, otters help regulate prey populations and maintain a balanced aquatic environment. The project also emphasizes the role of conservation in regions where human activity has heavily impacted local wildlife. By documenting their specific methodology, the researchers hope to provide a useful model for other areas facing similar environmental challenges.

The reintroduction of these otters serves as a precedent for future conservation initiatives. Ongoing monitoring will be necessary to ensure the individuals survive and integrate into the existing wild population. The knowledge gained from this effort could inform strategies for other species at risk, highlighting the importance of structured reintroduction in wildlife conservation. This work supports the broader objective of preserving biodiversity in environments facing significant external threats.