For many fisheries around the world, especially small-scale fisheries, long-term scientific datasets are scarce or entirely absent. Yet the people working on the water every day often hold detailed observations accumulated over decades. In a new review published in Reviews in Fish Biology and Fisheries, the authors examine what local ecological knowledge can contribute to understanding and managing overexploited fisheries. Drawing on 102 peer-reviewed studies published between 1999 and 2025, they assess both the strengths of this knowledge and the challenges involved in translating it into management action.
The review shows that local ecological knowledge can provide information that conventional monitoring programmes frequently miss. Fishers' observations have been used to reconstruct ecological baselines extending 50 to 80 years into the past, identify spawning and nursery habitats, document changes in species distributions, and detect declines in abundance. These insights are particularly valuable in regions where monitoring is limited or where ecological changes began long before systematic surveys were established.
Foreseeing explotation
A key contribution of the study is its attempt to quantify how often this knowledge helps identify signs of overexploitation. Across the reviewed literature, 85% of studies reported at least one indicator of overexploitation based on local ecological knowledge. The authors also describe how fishers can provide spatially detailed information on habitats and seasonal movements, and in some cases detect ecosystem changes before they become visible in formal datasets.
At the same time, demonstrating ecological value is only part of the story. While local ecological knowledge was frequently used to document environmental change, far fewer studies reported that it influenced management. Only 8% of the reviewed studies documented a formally implemented management action linked to this evidence. The authors suggest that the main obstacle is not the quality of the knowledge itself, but the institutional arrangements through which fisheries decisions are made.
Comparisons among case studies from Fiji, the Solomon Islands, Guyana, Egypt, and Canada point to a recurring pattern. Where local ecological knowledge was successfully incorporated into management, there were generally clear pathways connecting communities to decision-making processes and some form of recognized resource rights or governance authority. In contrast, several examples showed that well-documented local observations remained outside formal management systems despite being ecologically relevant.
Aware of limitations
The authors are careful not to present local ecological knowledge as a substitute for scientific research. They note that observations of declining catches, smaller fish, or changing distributions can have multiple causes, including habitat degradation and climate-related changes, and therefore benefit from validation against independent data whenever possible. They also acknowledge that the review is limited to English-language, peer-reviewed studies and may not fully capture experiences from regions where this knowledge is widely used but less frequently documented in the academic literature.
Even with these caveats, the article suggests that one of the most important questions facing fisheries governance today is no longer whether local ecological knowledge has value, but how institutions can make better use of evidence that is already available.