Satoshi Sakizaka, assistant professor at Hokkaido University's Graduate School of Environmental Earth Science, and Satoshi Terui, assistant professor at the University of North Carolina at Greensboro, have found that the frequent release of juvenile fish into rivers is counterproductive to increasing fishery resources in rivers. , This was revealed by an analysis by Koichi Urabe, Senior Researcher at the Hokkaido Research Organization.
The research involved theoretical analysis based on simulations with 32 scenarios, and empirical analysis based on fish community data collected over the past 21 years in rivers in Hokkaido collected by the Hokkaido Research Organization.
According to the theoretical analysis, the release intensified the interspecies competition within the community, resulting in exclusion of non-released species in most scenarios.In addition, excessive stocking increased intraspecific competition and inhibited natural breeding.
Empirical analyzes revealed that the density of cherry salmon and other fish species decreased in rivers with large-scale stocking of cherry salmon.The research group believes that the impact of the stocking is intensifying competition between and within species, which is having the opposite effect of increasing fishery resources.
The research group believes that the recovery of fishery resources requires drastic measures such as improving and restoring river habitats, rather than releasing juvenile fish. I think I need to get my hands on it.
Paper information:[Proceedings of the National Academy of Sciences] Intentional release of native species undermines ecological stability
