Data from: Bayesian species recognition and abundance estimation: Unravelling the mysteries of salmonid migration in the Teno River

In Teno River, annual sonar monitoring is used to estimate the abundance
of three salmonid species: Atlantic salmon, pink salmon and sea trout.
However, the size distribution of these species is partially overlapping
making species recognition impossible from plain sonar data. A Bayesian
model was developed to tackle this problem and to estimate abundance and
migration timing for these three species. The model integrates multiple
sources of data including catch, video count, daily average school sizes
and expert knowledge. Given the limited catch and video statistics for
2021, the use of school size data and expert knowledge on migration
intensity enhanced the estimation when other data sources were
unavailable. The model estimated a median of 11.8 thousand Atlantic
salmon, 6.6 thousand sea trout and 52.0 thousand pink salmon migrating
into the river during 2021. These findings offer a more accurate
representation of species distribution, support future conservation and
management efforts, and provide a modelling-based solution for
distinguishing similarly sized species from sonar counting data.