Table 1. — Monthly, rpiarlerhj, and annual catches of skipjack tuna in Haicaii, 1952- 



IThousands of poundsl 



Period of time 



Month: 



January. -. 

 February,. 



March 



April 



May 



June 



July 



August 



September 

 October. .- 

 November. 

 December. 



Quarter: 



First 



Second 



Third 



Fourth 



Annual 



29 



90 



56 



387 



678 

 818 

 1,654 

 1,758 

 987 

 576 

 110 

 249 



175 

 1.783 

 4.399 



935 

 7,292 



1953 



200 



204 



576 



864 



1,240 



2.241 



1.510 



2.142 



1,281 



1.199 



218 



384 



980 

 4.345 

 4.933 

 1.801 

 22,059 



271 



185 



359 



7.59 



1.132 



2.804 



3.705 



2.178 



1.049 



1.121 



390 



815 

 4.095 1 

 6,932 

 1.579 

 14,021 



1955 



118 



263 



681 



1,399 



2,197 



1,824 



1,170 



993 



440 



272 



239 



479 

 4.277 

 3.987 



951 

 9.694 



1956 



322 



281 



230 



433 



1.375 



1.926 



2.321 



1 . ,586 



1.065 



725 



635 



243 



833 



3.734 



4.962 



1,603 



11.132 



524 

 133 

 4,54 

 331 

 816 

 812 

 919 

 698 

 489 

 530 

 282 

 142 



1,111 

 1,959 

 2,106 

 954 

 6.130 



638 

 236 

 15! 

 792 

 277 

 948 

 1,405 

 1,191 

 631 

 186 

 144 

 235 



1.025 

 2.017 

 3,227 

 565 

 6,834 



215 



107 



397 



839 



1,757 



1.679 



2.382 



1.815 



1.377 



1,064 



626 



155 



719 



4,275 



5,574 



1,845 



12,413 



1960 



242 

 179 

 327 

 411 

 842 

 776 

 1.430 

 1.396 

 690 

 439 

 219 

 409 



748 

 2,029 

 3.516 



1,067 

 7,360 



1961 



492 



247 



600 



620 



930 



2,721 



2,288 



1,359 



705 



516 



213 



203 



1.339 

 4,271 

 4,352 

 932 

 10,894 



459 



412 



199 



480 



1,178 



2.308 



1.809 



922 



568 



525 



170 



385 



1.070 

 3.966 

 3.299 

 1.080 

 9.415 



Range 



29-638 

 90-412 

 56-600 

 331-864 

 277-1 . 757 

 776-2.804 

 919-3.705 

 698-2.178 

 489-1.377 

 186-1.199 

 110-635 

 68-409 



175-1.339 

 1.783-4.695 

 2.106-6.932 



565-1.844 

 6.130-14.021 



Average 



317 

 199 

 328 

 600 



1.048 



1.748 



1.932 



1.474 



893 



666 



298 



246 



845 

 3.395 

 4.299 

 1.210 

 9.749 



MONTHLY, QUARTERLY, AND ANNUAL CATCHES 



The seasonal character of the Hawaiian skip- 

 jack tuna fishery is shown by the monthly and 

 quarterly catches in 1952-62 (table 1). The 

 catch usually increased gradually from April 

 to a peak in June, July, or August and then 

 declined progressively to a low level in Decem- 

 ber. Usually February had the smallest catch 

 and July the largest. Also, the catch usually 

 rose in January following the progressive de- 

 cline from the summer peak to December. 



The quarterly catches showed the same trend 

 as the monthly landings. First-quarter catches 

 were usually the smallest and averaged 0.8 

 million pounds. Second-quarter catches re- 

 flected the increased fishing activity during the 

 spring and averaged about 3.4 million pounds. 

 Third-quarter landings were rather consistently 

 the largest and averaged 4.3 million pounds ; 

 only in 1955 and 1962 did second-quarter 

 catches exceed those of the third quarter. The 

 fourth-quarter catches declined to an average 

 of 1.2 million pounds. 



The variations of the annual catches were 

 large. In 1952-62, there were 4 poor years — 

 1952, 1957, 1958, and 1960— in which the 

 matches were far below the 11-year average of 

 9.7 million pounds. The catches in 1955 and 

 1962 were close to the 11-year average, and 

 those of the remaining years were above av- 

 erage. The maximum catch of 14.0 million 

 pounds occurred in 1954; the minimum of 6.1 

 million pounds was in 1957. 



INSHORE AND OFFSHORE CATCHES 



For this study, I consider the inshore area 

 to extend from the coastline to 20 miles at sea 

 and the offshore area to include all statistical 

 areas beyond 20 miles from the coastline. 



The catch reports used in this study were 

 from vessels that fished for skipjack full time. 

 The total weight landed by these vessels and 

 the effort expended to produce it are hereafter 

 called sample catch and sample effort. In addi- 

 tion to the catches made by these vessels, 

 catches were made by vessels that fished for 

 skipjack tuna only part time. The total weight 

 landed by vessels that fished full time and 

 those that fished part time is hereafter called 

 total catch and the effort expended to produce 

 it is total effort. Data on total catch were ob- 

 tained from annual summaries of catch issued 

 by the Hawaii Division of Fish and Game. 



I obtained the sample catch (all areas) and 

 the sample inshore catch from the catch reports, 

 and from these data, I calculated the percentage 

 of the catch made inshore. The total inshore 

 catch was estimated by applying the percentage 

 of the catch made inshore to the total catch. 

 The estimated annual inshore catches (table 2) 

 are shown in relation to the total catch and 

 the estimated total oflFshore catch in figure 1. 



The percentage of the catch made inshore 

 ranged from 63 percent in 1954 to 90 percent 

 in 1960. During the poor years — 1952, 1957, 

 1958, and 1960 — the inshore catch averaged 

 83 percent of the total catch, whereas in 



U.S. FISH AND WILDLIFE SERVICE 



183 



