A paradoxical knowledge gap in science for critically endangered fishes and game fishes during the sixth mass extinction

Centenarian lifespans of three freshwater fish species in Arizona reveal the exceptional longevity of the buffalofishes (Ictiobus)

During the 1910s three buffalofish species (Catostomidae: Ictiobus cyprinellus, I. bubalus, I. niger) were reared in ponds along the Mississippi River. Individuals of these buffalofishes were transported to locations across the United States to support or establish commercial fisheries, including Roosevelt Lake, Arizona in 1918. During the 1930s-1960s a commercial fishery existed on Roosevelt Lake, ending by 1970. Scarce information exists on Arizona buffalofishes since. From 2018 to 2023 we studied buffalofishes from nearby Apache Lake (adjacent and downstream of Roosevelt Lake) in collaboration with anglers. Here we show that > 90% of buffalofishes captured from Apache Lake are more than 80 years old and that some of the original buffalofishes from the Arizona stocking in 1918 are likely still alive. Using unique markings on old-age buffalofishes, we demonstrate how individuals are identified and inform dozens of recaptures. We now know all species of USA Ictiobus can live more than 100 years, making it the only genus of animal besides marine rockfishes (Sebastes) for which three or more species have been shown to live > 100 years. Our citizen-science collaboration has revealed remarkable longevity for freshwater fishes and has fundamentally redefined our understanding of the genus Ictiobus itself.

Recreational anglers' preferences about harvest regulations to protect a threatened freshwater fish in France

A number of freshwater fish particularly migratory species are currently under threat. As the pressure of recreational fishing has intensified, this activity needs to be more regulated to halt the decline of threatened fish stocks. This paper presents results of an economic valuation study of anglers' preferences for a change in the rules applying to Twaite shad fisheries in south-western France. Twaite shad has become a "near-threatened" species, with the same IUCN status as the Atlantic salmon. As shad recreational angling continues to be open access, new regulations are required to limit recreational harvest in support of a management strategy to prevent stock reduction even to foster stock recovery. We combined a deliberative choice experiment with open group discussion to obtain an in-depth understanding of anglers' preferences between two types of traditional regulatory instrument - a license fee or a bag limit. The closure of the fishery served as the reference scenario. The results indicate that the majority of anglers were aware of the decline of Twaite shad stocks. The recreational value of the species remains high, especially for those who already target migratory species. Although econometric estimations show that there are heterogeneous preferences across anglers, there were support for a change toward a bag limit, and an aversion for a high-priced licence fee. The findings also provided two key insights to improve recreational fishing management and preservation policy for threatened species. The communication of observation data on fish stock could not be considered as a sufficient ecological information to ensure threatened species monitoring leads to an effective co-management with anglers' community. Anglers' aversion to loss can be seen as a behaviour mechanism towards the preservation of the species rather than to its use.

Sharkipedia: a curated open access database of shark and ray life history traits and abundance time-series

A curated database of shark and ray biological data is increasingly necessary both to support fisheries management and conservation efforts, and to test the generality of hypotheses of vertebrate macroecology and macroevolution. Sharks and rays are one of the most charismatic, evolutionary distinct, and threatened lineages of vertebrates, comprising around 1,250 species. To accelerate shark and ray conservation and science, we developed Sharkipedia as a curated open-source database and research initiative to make all published biological traits and population trends accessible to everyone. Sharkipedia hosts information on 58 life history traits from 274 sources, for 170 species, from 39 families, and 12 orders related to length (n = 9 traits), age (8), growth (12), reproduction (19), demography (5), and allometric relationships (5), as well as 871 population time-series from 202 species. Sharkipedia relies on the backbone taxonomy of the IUCN Red List and the bibliography of Shark-References. Sharkipedia has profound potential to support the rapidly growing data demands of fisheries management, international trade regulation as well as anchoring vertebrate macroecology and macroevolution.