





1968 



1969 



1970 



1971 



1972 



1973 



1974 



1975 



1976 



1977 



1978 



TOTALS 



\ Cope Melville 



*• 

















1 

 150 







2 



425 



3 



Ribbon Reef #10 S — *~. \ \ 

 Lizord Island ^S. \ "\ 

 Yonge Reef. \. t 

 Carter Reef ^-.Cope Flattery 

 Day Reef ^J V 



*• 



— 



1 

 650 



— 







19 

 321 



(17) 



59 

 452 



99 

 449 

 (86) 



119 

 365 

 (III) 



45 

 328 



53 



440 



26 



387 



421 



Ribbon Reefs #4-9 / 



V/vCape Bedford 



Cooktown/ \ 1 



*• 



— 







— 







20 



348 

 (18) 



58 

 440 



37 

 450 

 (27) 



84 

 415 

 (72) 



93 

 436 



18 

 541 

 (12) 



9 



450 



319 



Ribbon Reefs* 1-3 \ ) \ 

 Lena Reef \ \=? \ 

 Ruby Reef Escape Reef 1 { % \ 

 Pearl Reef ( \ ~* \ 

 Agincourt Reefs #3-4 \ v \ 



* 







2 

 275 



6 

 475 



64 



411 

 (61) 



76 

 367 



70 

 394 



36 

 479 

 (20) 



29 

 416 



67 

 373 



28 

 384 



— 



378 



Agincourt Reef s # 1 - 2 \ \<J>\ 

 St Crispin Reef ) \0 

 Opal Reef S \ ^ 

 Linden Bank Onyx Reef f \ ** 

 Spur Reef Nicholos Reef \ 



♦> 







1 

 350 



12 

 346 



30 

 449 

 (25) 



123 

 403 

 (116) 



202 

 381 



214 

 444 

 (186) 



181 

 378 

 (176) 



244 

 439 



22 

 373 



16 

 338 



1,045 



Fin Reef I 



Euston Reef \ 



Flyn Reef \ Cape 



Jennie Louise Reef Hope Reef \ Grafton 



Chonnel Reef Thetford if**P 



\ 



s 6 



\264 



47 

 302 



92 

 286 



90 

 366 

 (88) r 



-65 

 -317 

 "(61) 



48 

 354 



25 

 384 

 (18) 



22 



314 



48 

 297 



21 



144 



2 

 415 



486 



Cairns'* [ 



&> 



V 



\ 



# 



— 



-I 



L Number q! martin tagged 

 — Average estimated weight at tagging (lb) 

 Number ot marlin in estimated weigh! figure 



4 

 456 



— 



— 



4 



TAGGING AREA^( 



\ 



V 



\ 



\ \ 



\ \ 



— 







— 



1 

 350 



— 











27 

 38 



3 

 35 



31 



Cardwell 



fa 



— 



V \ 



\ \ 



\ 1 



V 



\ 















6 

 37 



2 



38 



8 





























Townsville 



-V 





x 



•v 1 











1 

 70 





1 





26 

 264 

 (26) 



51 

 308 

 (51) 



110 

 303 

 (110) 



184 

 394 

 (174) 



303 

 367 

 (288) 



438 



398 

 (438) 



411 

 445 

 (337) 



436 

 380 



(411) 



501 

 406 

 (501) 



176 

 312 

 (170) 



60 

 356 

 (60) 



2,696 



385 



(2,566) 









Figure 3. — Locations of black marlin lagging immediate lo !he Greal Barrier Reef off north Queensland, Auslralia, by 30° latitude areas, by year and number of black marlin 

 lagged, and average estimated weight by anglers at time of tagging. Note — estimated weight may vary from actual weight, see text. (For conversion of pounds to kilograms, lb 

 x 0.4536 = kg). 



TAGGING AND RECOVERY WEIGHT DATA 



Upon tagging a black marlin, one of the items requested from 

 the angler was an estimate of the marlin's weight. The average 

 weight estimated by angler at the time of tagging, for 2,566 marlin 

 having weight data reported, was 175 kg (385 lb). Average 

 estimated weights by year and by 30° latitude area off north 

 Queensland are given on Figure 3. The largest recorded average 

 weight by year was 202 kg (445 lb) in 1974. The largest number of 

 marlin tagged, and the largest average weight of 186 kg (410 lb), 

 occured at lat. 16°00' to 16°30'S. This area includes Agincourt 

 Reefs #\ and #2, Linden Bank, and St. Crispan, Opal, Spur, 

 Onyx, and Nicholas Reefs. 



Estimated tagging weight varied greatly with landing weight as 

 seen by catches recorded at Cairns and Lizard Island weighing sta- 

 tions from 1 September to 31 December 1970-78 (Table 4). The 

 average weight of black marlin from the landing records is 346 kg 

 (762 lb). Estimates of weight at time of tagging averaged 175 kg 

 (385 lb) or 171 kg (377 lb) less than the weights recorded at the 

 weighing station. 



The weight data on recaptured marlin were sometimes submit- 

 ted with additional information on the recovery. In the case of the 

 commercial longline fishery the weights were with the bill and a 

 portion of the head removed at about the area of the eye orbit. 

 The reported weight must therefore be increased by a factor of 1 . 1 

 (Ueyanagi 1 ) to give the approximate "round weight" of the fish. 



Fifty-one marlin had weight and/or length data accompanying 

 information on the geographical location and time of recapture. 

 Upon examination of the weight and length data for the recap- 

 tures, it was determined that for five marlin the data were inade- 

 quate to determine total weight. Of 46 black marlin recaptured by 

 the commercial longline fishery, having angler estimated weight 

 data at tagging, 30 were recaptured at total weight less than 

 estimated by the angler, 15 at weights greater than estimated, and 

 1 at the same weight. The average angler overestimate of black 

 marlin recaptured at tagging, when compared with the recapture 



'Shoji Ueyanagi, Far Seas Fisheries Research Laboratory, Japan Fisheries Agen- 

 cy, 1000 Orido, Shimizu. 424, Japan, pers. commun. 





