Effect of riverbed conditions on survival of planted eyed eggs in chum salmon Oncorhynchus keta

Masaya Iida, Satoshi Imai, Satoshi Katayama

    Research output: Contribution to journalArticlepeer-review

    3 Citations (Scopus)

    Abstract

    Wild stocks of chum salmon Oncorhynchus keta are supplemented by hatchery fry enhancement programs in northern Honshu, Japan. To maintain these programs, there is a need to reduce expenses and labor. Eyed egg planting is more cost effective than hatchery production of fry. Therefore, we evaluated the effect of environmental conditions on survival of chum salmon eyed eggs planted using Whitlock–Vibert boxes. We measured the percent cumulative weight of fine sediments, Fredle index (FI) as a measure of permeability, vertical hydraulic gradient, water depth (WD), and flow velocity at planting locations. Egg-to-fry survival averaged 92.7% (range: 57.2–100%) in 2013 (N = 19) and 71.5% (range: 6.4–100%) in 2014 (N = 23). Survival was significantly positively correlated with FI and flow velocity, negatively associated with percent cumulative weight of fine sediments and WD. Vertical hydraulic gradient had no effect on survival. Our results suggest that a higher FI (i.e., low amount of fine material and larger particle size), higher flow velocity, and shallower WD reduce the mortality of planted chum salmon eyed eggs. This is likely a result of increased permeability in the substrate and restriction of fine sediment intrusion into the incubation zone.

    Original languageEnglish
    Pages (from-to)291-300
    Number of pages10
    JournalFisheries Science
    Volume83
    Issue number2
    DOIs
    Publication statusPublished - 2017 Mar 1

    Keywords

    • Chum salmon
    • Eyed egg planting
    • Optimum riverbed
    • Survival rate

    ASJC Scopus subject areas

    • Aquatic Science

    Fingerprint

    Dive into the research topics of 'Effect of riverbed conditions on survival of planted eyed eggs in chum salmon Oncorhynchus keta'. Together they form a unique fingerprint.

    Cite this