Migration history of Sakhalin taimen Hucho perryi captured in the Sea of Okhotsk, northern Japan, using otolith Sr:Ca ratios

Abstract

Sakhalin taimen Hucho perryi populations have decreased drastically to near extinction. It is urgent to establish an effective conservation strategy based on an understanding of the characteristics of migration and habitat use of this species. We examined the migration history of anadromous Sakhalin taimen captured off the Sarufutsu coast, northern Hokkaido, Japan, using otolith Sr:Ca ratios and also examined the relationship between their otolith Sr:Ca ratios during freshwater and seawater residence in a rearing experiment. Otolith Sr:Ca ratios of some fish from the Sarufutsu coast showed freshwater levels (0.5-4.0 9 10 -3 ) near the core, which thereafter increased to brackish water levels (4.0-6.0 9 10 -3 ), and then to seawater levels (6.0-10.0 9 10 -3 ) in the outermost regions. Those findings indicate that specimens from the Sarufutsu coast migrated to the brackish water region or the sea and spent most of their lives there. The anadromous migration pattern including the timing of downstream migration seems to be flexible among individuals in the species. They migrate between freshwater and seawater or brackish water several times during their lives, showing extensive habitat use. It is essential to secure the continuity among the freshwater, brackish water, and seawater areas for their effective conservation.

Migration of Sakhalin taimen (Parahucho perryi): evidence of freshwater resident life history types

“…The taimen examined by Edo et al (2005) were >8 years old at time of capture. In contrast, Suzuki et al (2011) found that some fish migrated to sea before age-3. Arai et al (2004) also examined three juvenile taimen (<13.0 cm fork length) and one adult taimen (70.0 cm fork length) that had not migrated to saltwater based on otolith microchemical profiles.…”

“…The Sakhalin taimen, unlike other taimen species, is generally considered to be anadromous (Arai et al 2004;Edo et al 2005;Suzuki et al 2011). Kawamura et al (1983) described capture of taimen from brackish waters on the eastern shore of Hokkaido Island, Japan.…”

“…Edo et al (2005) classified taimen captured near the mouth of the Sarufutsu River, on the island of Hokkaido, as anadromous based on capture in near-shore set-nets, stomach contents containing marine species, and silvery coloration. Suzuki et al (2011) used otolith microchemistry to confirm that seven taimen captured in set nets near the Sarufutsu River were anadromous. In all these cases, the taimen captured and classified as anadromous ranged from 46.0 to 78.4 cm in length.…”

Habitat residency and movement patterns of Centropomus parallelus juveniles in a subtropical estuarine complex

“…Otoliths are metabolically inert structures as new mineral material is neither resorbed nor reworked after deposition, and the uptake of elements into the growing structures usually reflects the physical and chemical aquatic environment (Campana et al, 2000). The Sr:Ca ratios of otoliths can be used as natural tags to describe fish movements between freshwater, brackish and seawater habitats (Secor & Rooker, 2000;Suzuki et al, 2011;Mai et al, 2014). Furthermore, for a wide range of salinities and fish species a well-known positive relationship exists between Sr:Ca ratios in the otoliths and the water where fishes live (Kraus & Secor, 2004).…”

Seasonal stream habitat of adult Sakhalin taimen, Parahucho perryi, in the Bekanbeushi River system, eastern Hokkaido, Japan

“…However, less is known about the habitat and behavioural ecology of P. perryi fry and juveniles. Previous studies have focused on the anadromous form in either Sakhalin or Hokkaido (Arai et al 2004;Edo et al 2005;Honda et al 2010a;Suzuki et al 2011;Zimmerman et al 2011). With the exception of spawning season information, we also know little about adult P. perryi.…”