SEAFDEC/TDINSTITUTIONAL REPOSITORY
    • English
    • ไทย
    • 日本語
  • English 
    • English
    • ไทย
    • 日本語
  • Login
View Item 
  •   SEAFDEC/TD Institutional Repository (STIR)
  • 01 SEAFDEC/TD Publications
  • 09 Conference Proceedings
  • Consolidating the Strategies for Fishery Resources Enhancement in Southeast Asia. Proceedings of the Symposium on Strategy for Fisheries Resources Enhancement in the Southeast Asian Region
  • View Item
  •   SEAFDEC/TD Institutional Repository (STIR)
  • 01 SEAFDEC/TD Publications
  • 09 Conference Proceedings
  • Consolidating the Strategies for Fishery Resources Enhancement in Southeast Asia. Proceedings of the Symposium on Strategy for Fisheries Resources Enhancement in the Southeast Asian Region
  • View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.

Stock Enhancement of Portunid Crabs in Japan

Thumbnail
View/Open
ObataY2016.pdf (412.6Kb)
Downloads: 163
Date
2016
Author
Obata, Yasuhiro
Page views
463
Share 
 
Metadata
Show full item record
Abstract
Portunid crabs such as swimming crab Portunus trituberculatus, blue swimming crab P. pelagicus and mud crab species Scylla paramamosain and S. serrata are one of the most important fishery resources in Japanese coastal waters. The annual catch of the Portunid crabs have fluctuated between arrow up ,300 and 5,600 tons in Japan. In order to sustain and/or increase the Portunid crabs stock, a number of 30 million hatchery-produced juveniles have been released annually since the late 1980s. Estimating recapture rates of stocked crabs is indispensable to evaluate the effectiveness of stock enhancement programs, so that it is necessary to develop marking methods that distinguish between wild and hatchery-released individuals. The stocking effectiveness of Portunid crabs have been difficult to estimate because there have been no appropriate methods to mark small body sized juveniles which frequently molt. Therefore, recently, we developed a technique to mark juveniles and eventually estimated the contribution rates of released crabs to the total catch of the mud crab and swimming crab. The mixture rate of released juveniles in the total catch of the mud crab is estimated by the method of genetic stock identification, to be 5-19.7%. The contribution of released juveniles to the total catch was estimated to be about 0.5-1 metric ton. The recapture rate of released juveniles of the swimming crab is estimated by the marking technique of clipping swimming leg dactylus. Estimated contribution rate of marked crabs to the landings was about 3.0%. Effective marking methods and potential of stock enhancement programs for the Portunid crabs is discussed.
URI
http://hdl.handle.net/20.500.12067/713
Citation
Obata, Y. (2016). Stock enhancement of Portunid crabs in Japan. In H. Kawamura, T. Iwata, Y. Theparoonrat, N. Manajit, & V. T. Sulit (Eds.), Consolidating the Strategies for Fishery Resources Enhancement in Southeast Asia. Proceedings of the Symposium on Strategy for Fisheries Resources Enhancement in the Southeast Asian Region, Pattaya, Thailand, 27-30 July 2015 (pp. 157–-60). Samutprakan, Thailand: Training Department, Southeast Asian Fisheries Development Center.
Subject
Hatcheries; juveniles; resource management; stocking (organisms); resource conservation; stock assessment; stocks; catch statistics; commercial species; marine crustaceans; fishery resources; marking; Japan; Portunus trituberculatus; Portunus pelagicus; Scylla serrata; Scylla paramamosain
Collections
  • Consolidating the Strategies for Fishery Resources Enhancement in Southeast Asia. Proceedings of the Symposium on Strategy for Fisheries Resources Enhancement in the Southeast Asian Region [32]

© SEAFDEC/TD 2025
Contact Us | Send Feedback
 

 

Browse

All of STIRCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

My Account

LoginRegister

Statistics

View Usage Statistics

© SEAFDEC/TD 2025
Contact Us | Send Feedback