中海・本庄工区におけるアサリの成長と生残に及ぼす潮通しの効果  [in Japanese] Effects of Sea-Water Induction Pipes to Growth and Survival of Ruditapes philippinarum in Honjo Area of Lake Nakaumi, Southwest Japan  [in Japanese]

Access this Article

Search this Article

Author(s)

Abstract

斐伊川水系の末端に位置する中海は、境水道を通して日本海につながる中~高塩分の汽水湖である。中海の北西部には、戦後の米不足対策のために干拓地造成が計画され、本庄工区と呼ばれる堰堤によって区画された水域が形成された。本庄工区は堰堤工事がほぼ完成して以降、西部承水路を通して中海の湖水がわずかに出入りするのみの閉鎖的環境となった。1988年以降、干拓計画はこの段階で凍結されていたが、1996年には島根県が本水域の開発計画再開を決議した。これに際して、干拓の代案として水産利用の可能性も検討する事となり、1998年3月中国四国農政局により、北部承水路と本庄工区を隔てる北部承水路の堰堤に、直径2.5m長さ26mのパイプ2本(以下、潮通しパイプ)が設置され、この前後で、本水域における水の交流量・水質・底質・生物相の変化などの調査が行われた。また、農政局はアサリを水産振興の主軸の一つと考え、本庄工区内のこの潮通しパイプ付近に覆砂を施して、同年6月にアサリ成貝約1tを放流し、生残と成長を調査した。

Growth and survival rate were examined for adult Ruditapes philippinarum in Honjo Area of Lake Nakaumi.This area is a brackish lake enclosed by embankments built for reclamation. Two pipes for sea-water inductionof 2.5m in diameter were constructed on March 1998, to investigate potential of fishery promotion. Containerscarrying 50 individuals of Ruditapes each were set on lake bottom of 2 stations ; (1) Pipe-Front in Honjo and (2)Off-Eshima in Honjo Area. Growth, Survival rate and water quality (temperature, salinity, dissolved oxygen) wereexamined between 1.5m and 4m in water depth for these stations, from June 4 to November 5 in 1998. Shellgrowth is apparently higher among individuals set on 1.5m depth than on 4m depth, for both Pipe-Front and Off-Eshima stations. This low growth on 4m depth was supposed to be derived from combined factors such as lowerdissolved oxygen, lower food supply, lower water current effect and so on. Mass mortality occurred around offEshima Island in the end of July. This event was derived by concurrent death of sea algae, Cladofphora speciosa.The water current through the induction pipes appears to make better environment for animals enough to ayoidthe influence of this mortal event. However the pipes could not avoid the low growth of Ruditapes on 4m depth.

Journal

  • Journal of Fisheries Engineering

    Journal of Fisheries Engineering 37(1), 45-54, 2000-07-31

    The Japanese Society of Fisheries Engineering

References:  18

Cited by:  1

Codes

  • NII Article ID (NAID)
    10008273737
  • NII NACSIS-CAT ID (NCID)
    AN10278554
  • Text Lang
    JPN
  • Article Type
    Journal Article
  • ISSN
    09167617
  • NDL Article ID
    5459765
  • NDL Source Classification
    ZR26(科学技術--農林水産--水産)
  • NDL Call No.
    Z18-1327
  • Data Source
    CJP  CJPref  NDL  J-STAGE  JASI 
Page Top