Movement patterns of freshwater fish in restoration areas in an agricultural channel, Southern Okayama, Western Japan, in relation to effectiveness for fish conservation

To clarify movement patterns of freshwater fish inhabiting restoration areas in agricultural channels in relation to effectiveness for fish conservation, we conducted fish samplings at five study stations with different types of restoration method (wooden raft walkway, fish nursery blocks, and deep water) in an agricultural channel (areas that did not dry-up even in the non-irrigation period) southern Okayama, western Japan in July and October 2014 and January, July, October and December 2015. In the samplings, we carried out mark recapture investigations on six fish species (Carassius sp., Tanakia limbata, Acheilognathus rhombeus, Candidia sieboldii, Misgurnus anguillicaudatus and Odontobutis obscura) to evaluate the habitat utilization and seasonal movement within the restoration areas. In the restoration areas, we recaptured 133 marked fish individuals including all six species during the investigation period. Of the fish, 114 and 19 individuals were recaptured at the same and different study stations where the fish were released, respectively, indicating that many fish individuals continuously inhabit the same restoration area. These results indicate that the restoration areas can provide suitable habitats for fish in this study channel.