Migratory behaviour of adult chum salmon, Oncorhynchus keta, in a reconstructed reach of the Shibetsu River, Japan

Abstract

During 2004During -2006 adult chum salmon, Oncorhynchus keta (Walbaum), were tagged with electromyogram (EMG) transmitters and depth/temperature loggers and tracked along both the channelised and reconstructed segments of the Shibetsu River, Japan to assess the effects of the river re-meandering construction on upstream migration. Holding time of chum salmon in the reconstructed segment was longer than in the channelised segment. Further, greater diversity of physical condition in water velocity was observed in the reconstructed segment in 2005. Swimming speeds decreased during holding and often exceeded the critical swimming speed (U crit ). It appears that the physical characteristics developed in the reconstructed segment may be suitable for holding of chum salmon. Further, swimming speed exceeding U crit prior to holding may be exhaustive so holding behaviour may be important for muscle recovery as well as for efficient swimming to reduce the energetic cost during upstream migration. K E Y W O R D S : chum salmon, EMG transmitter, radio telemetry, reconstruction, upstream migration.

Fish habitat rehabilitation using wood in the world

“…The remeandering of the river channel aims at rejuvenating floodplain and river ecosystems through the recovery of hydrogeomorphical dynamics such as inundation of the floodplain, bank erosion, and point bar formation. The effects of the remeandering have been examined on fish (Kawaguchi et al 2005;Akita et al 2006;Makiguchi et al 2007Makiguchi et al , 2008, benthic macroinvertebrate Nakamura 2006, 2008;, bird (Nakano et al 2007), and bat (Akasaka et al 2009). Kawaguchi et al (2005) reported that adult salmonids (pink and masu salmon, white-spotted char, and rainbow trout) more than 300 mm in body length and juvenile masu salmon were found around trees that fell naturally into the river due to bank erosion.…”

EMG telemetry studies on upstream migration of chum salmon in the Toyohira river, Hokkaido, Japan

“…Adult salmon swim below and above U crit during upstream migration, using burst swimming (Hinch and Bratty 2000;Hinch and Rand 2000;Hinch et al 2002). Makiguchi et al (2008) found that chum salmon during upstream migration consistently showed holding behavior following high swimming speed exceeding U crit and indicated that the swimming behavior prior to holding represent exhaustive swimming. Therefore, unsuccessful fish were likely experiencing levels of fatigue and stress during their passage at the protection bed of #5 ground sill and the fishway of #6/7 ground sill.…”

“…EMG telemetry has been proven as an effective technique to examine the continuous swimming activity of sockeye salmon (Oncorhynchus nerka) (Hinch et al 1996), pink salmon (O. gorbuscha) , and chum salmon (O. keta) (Makiguchi et al 2008). The swimming behaviors of migrating fish have been classified into three major categories: sustained, prolonged, and burst swimming (Hammer 1995).…”

Ecology and welfare of aquatic animals in wild capture fisheries

“…Channelization of rivers is another common form of fisheries habitat alteration in agricultural, urban and industrial areas. Usually this involves straightening and stabilization of river banks with rocks or concrete, dredging of sediments, use of levee banks for flood mitigation and removal of snags and woody debris in order to improve navigability (Boesch 2006;Makiguchi et al 2008). All of these processes decrease access of aquatic animals to suitable living, spawning and nursery habitat, resulting in significant loss of recruitment capacity and biodiversity (Mauney and Harp 1979;Rochette et al 2010), both of which must be considered welfare concerns under the nature-based definition.…”