Usefulness of a Japanese internet community for fish conservation

Large biodiversity datasets are currently being collected not only by experts and amateur researchers, but also by the general public. In this study, records of non-native and Japanese Red List fishes observed by citizens were extracted from all 85,453 posts on the bulletin board system of WEB sakana-zukan, a web-based encyclopedia of Japanese fishes that went online in 2002. We found 681 (0.8%) and 549 (0.6%) posts containing attached images of non-native and Red Data Book fishes, resulting in 418 and 362 Japanese distributional records respectively. The number of posts and the composition of non-native species reflected the Japanese inland fisheries policy to increase target species. These data included records of exotic species (eleven taxa) whose introduction to Japan had been unknown previously, as well as records of nine exotic/domestic species whose introductions into specific Japanese regions had been unknown. Additionally, we identified the range extension of one Red Data Book species. These photographs were stored in a public museum’s photographic collection for ongoing scientific use. Three heavy users of the website combined contributed 26.7% of the new distribution records (8/30 lots), while 15 light users contributed 50.0% (15/30 lots), suggesting that overall there is a greater contribution by light users. This indicates that a web community with abundant users can accumulate new biodiversity observations better than one with fewer users but many posts per user. Our results show that this web-community was able to contribute to monitoring non-native and Red List fishes in conjunction with expert participation, and therefore that web-communities targeting living organisms can contribute to biodiversity conservation.