Fix this text
SPC/Fisheries 12/WP. 16
Fix this text23 October, 1980
Fix this textCATCH RELATIONSHIPS IN FOUR DIFFERENT SKIPJACK AREAS
Fix this textIN THE WESTERN EQUATORIAL PACIFIC
Fix this textORIGINAL : ENGLISH
Fix this textSOUTH PACIFIC COMMISSION
Fix this textTWELFTH REGIONAL TECHNICAL MEETING ON FISHERIES
Fix this text(Noumea, New Caledonia, 17-21 November 1980)
Fix this textby
Fix this textTamotsu Tanaka and Masakazu Yao,
Fix this textTohoku Regional Fisheries Researce Laboratory, Japan.
Fix this text1.0 INTRODUCTION
Fix this textJapanese distant-water skipjack bait boats have exploited the "Nanpo
Fix this textGyojo (southern ground)” since 1964. There are four significant ocean
Fix this textcurrents in the southern grounds extending from 24°N to 2 S latitude. The
Fix this textfishing activities begin in each of the currents when the currents intensify.
Fix this textSize of major groups increase from south to north, and the amount of catch
Fix this textalso changes so as to imply the migration of fish. A preliminary examination
Fix this textof data seems to provide a means for pre-season forecast of catches there.
Fix this text2 .0 DATA
Fix this textThe present examination is based on interviews with master fishermen,
Fix this textcaptains or other leading crews of the the skipjack bait boats that unloa e
Fix this textat Yaizu during 1951 through 1980. Also size composition data were collected
Fix this texteither through measuring body length or recording amount of landing by gra e.
Fix this text3.0 FISHING AREAS BY CURRENTS
Fix this textIt has already been noticed that there is a close relationship between
Fix this textocean currents and fishing activities in the southern grounds (Tanaka 1974,
Fix this text1975). In summary, there are four fishing areas in each of the prominent
Fix this textcurrents. (1) Skipjack are fished in the waters around the Subtropical
Fix this textCounter Current that flows eastward around 20°N latitude. The fishing season
Fix this textthere lasts from late June to September. Most boats operate here for a
Fix this textcruise or two after the albacore season finishes in the waters adjacent to
Fix this textJapan. (2) Then the skipjack boats shift to the North Equatorial Counter
Fix this textCurrent in August, and work there until December or January. The current
Fix this textchanges its path from year to year, and the major operation area also varies
Fix this textaccordingly. In these two areas, the high sea surface temperature, 29 -
Fix this text30°C, often brings about mass mortality of bait fish. This is particularly
Fix this textserious for long-lasting operations in the North Equatorial Counter Current
Fix this textarea. As a counter measure for tW loss of bait, many boats operate in
Fix this textcooler waters east of the Marshall Islands, where the sea surface temperature
Fix this textis 27° - 28°C. However, warm waters of 29°C or above have been expanding m
Fix this textrecent years, thus hampering profitable operations.
Fix this text1243/80
Fix this textIt's easy and takes two shakes of a lamb's tail!
With your Trove account you can:
http://nla.gov.au/nla.obj-3416560018
Select the images you want to download, or the whole document.
You can order a copy of this work from Copies Direct.
Copies Direct supplies reproductions of collection material for a fee. This service is offered by the National Library of Australia
Unknown
Copyright status could not be determined due to data in the record being incomplete or inaccurate.
For more information please see: how copyright status is determined.
Copy and paste one of these options to share this book elsewhere.