Fish kills are events with biological, cultural and economic significance that occur around the world. The cause(s) of fish kills are often proximate and can be a result of multiple synergistic/additive factors that culminate to the loss of fishes. For example, factors can include extremely high-water temperatures, hypoxic conditions, algal blooms, and/or pollution in the water body. Despite the complexity and importance of fish kill events there is limited reporting within peer-reviewed journals and no recent synthesis of data from them.
We sought to understand the representation of freshwater fish kills in peer-reviewed journals around the world over time, characterize the factors that led to fish kills and identify trends over time that may help guide future management. A thorough search of published literature (using SCOPUS and Google Scholar) identified nearly 200 articles that were published from 1970 until 2026. For each article we collected data such as country of publication, year of publication, and the suggested cause(s) of the fish kill. Following analysis, we identified important differences in where published fish kills occur around the globe, with approximately 60% of fish kills in the literature being reported in the USA, Australia and India. We also found that publication number, as well as the variety of causes of fish kills increased over time. The highest number of reported fish kills were due to hypoxia, temperature or effects of additive/synergistic factors. In addition, we noted there is a lack of accessible data within peer-reviewed papers (such as data-access links) and little use of historical data when analysing fish kill events, which makes future analyses and interpretation of broader global trends difficult. Fish kills are a complex global phenomenon that needs greater reporting in published papers in the future.