Striped Marlin, Tetrapturus audax, Migration Patterns and Rates in the Northeast Pacific Ocean as Determined by a Cooperative Tagging Program: Its Relation to Resource Management JAMES L. SQUIRE Introduction were developed to obtain an understand­ catch rates are recorded in this area and ing of migratory patterns that could be surveys show the catch per angler day has Since billfish cannot be captured in useful in developing management plans ranged from 0.3 to 0.8 striped marlin large numbers to study movements for Pacific bill fish stocks. since 1969 (Squire, 1986). Some striped through tagging studies, marine anglers In 1963, the U.S Fish and Wildlife marlin are also landed at Mazatlan, who will tag and release fish provide an Service's Pacific Marine Game Fish Re­ Mex., and others are occasionally taken effective, alternate way to obtain infor­ search Center, Tiburon Marine Labora­ off other west coast ports of Mexico and mation on migration patterns. Billfish tory, Tiburon, Calif.. under the U.S. off Central and South America. High tagging by marine anglers in the Pacific Department of Interior, assumed respon­ catch rates are observed again off began in the middle 1950' s when tagging sibility from WHOI for support of the Ecuador. In the northeast Pacific, high equipment, distributed to anglers by the Cooperative Marine Game Fish Tagging catch rates for striped marlin are recorded Woods Hole Oceanographic Institution's Program in the Pacific area. In 1970 a from January to March off Mazatlan, (WHO!) Cooperative Marine Game Fish reorganization transferred the Tiburon Mex., and later in the year (April­ Tagging Program for tagging tunas and Laboratory and the tagging program to October) about the southeastern tip of the billfish in the Atlantic, was transported to the National Oceanic and Atmospheric Baja California peninsula (Eldridge and fishing areas in the Pacific. Administration's National Marine Fish­ Wares, 1974). The U.S. recreational Sailfish, Istiophorus platypterus, were eries Service (NMFS) In the U.S. De­ fishing fleet off southern California lands first tagged by bill fish anglers in the partment of Commerce. From 1963 to striped marlin from July through Octo­ northeast Pacific in 1954, and striped 1970 the State of California's Depart­ ber, with catches usually peaking in Sep­ marlin, Tetrapturus audax, were first ment of Fish and Game (CDFG) also pro­ tember; this area is the northern limit of tagged in 1957. In 1961, black marlin, vided tags to a select group of cooperat­ the recreational fishery in the eastern Makaira indica, were first tagged in the ing anglers to tag striped marlin (Squire. Pacific. southwest Pacific (Coral Sea), and in 1974). Longline fishing for billfish and tunas 1963 blue marlin, Makaira nigricans, The angler tagging programs have now has been conducted in the eastern Pacific were tagged in the central Pacific accounted for nearly all the tagged bill­ (east of long. 130oW.) since the late (Squire, 1974). Cooperative billfish tag­ fish in the Pacific at a relatively modest 1950's (Suda and Schaefer, 1965) and in ging programs with rod-and-reel anglers cost compared to that which would have the northeastern Pacific, where it has been incurred had the same fish been targeted on striped marlin, sailfish, and caught and tagged by more efficient long­ swordfish, Xiphias gladius, since 1963 line gear from research vessels. These (Joseph et aI., 1974). The catch rate for ABSTRACT-Migration patterns and billfish were tagged mainly in areas that striped marlin in the high catch rate areas rates for striped marlin, Tetrapturus audax, support active recreational bill fish fish­ of the northeastern Pacific has declined tagged and recaptured in the northeast Pacific Ocean during 1957-81 are reported eries. from about 18 fish per 1,000 hooks by time period and analyzed. Few long­ There is a major recreational fishery fished in the early 1960's to about 9-11 range migrations and no trans-Pacific mi­ for striped marlin in the northeastern fish per 1,000 hooks fished in 1980 grations were observed. Comparisons are Pacific centered about the southern tip of (Anonymous, 1962-80). This decline made with other types of physical and bio­ Mexico's Baja California Sur peninsula, came during the time tagging was con­ logical data Ihat might indicate seasonal movement (i.e., longline catch rates, areas and it is very important to the economy of ducted. Despite the substantial catch rate of slriped marlin spawning, movement of that area (Talbot and Wares, 1975). High decline since the beginning of the fish­ Ihermocline depth relative to fishing suc­ ery, the rate is among the highest in the cess). A tentalive hypothesis describing the Pacific, and this longline fishery pro­ seasonal movement of striped marlin in the vides in excess of 80 percent of the bill­ northeast Pacific and the total eastern James L. Squire is with the Southwest Fisheries Pacific is also proposed and presented in Center. National Marine Fisheries Service. fish tags recovered. From early 1977 to graphic form. NOAA. P,O Box 271. La Jolla. CA 92038 1980 longline fishing for bill fish and 26 Marine Fisheries Review tunas was prohibited by the Government Figure I.-Dart tags and tag report of Mexico within its 200-mile economic card used by the NMFS for the coop­ A erative tagging program for tagging zone. The highest catch rates for striped striped marlin in the northeast marlin are about the southern tip of Baja Pacific Ocean. ~ California Sur, within the 200-mile zone. Joint-venture longline operations were TVPE-A WHOI tag, small numbers resumed in 1980, providing a source of were used Initially. striped marlin tag recoveries. Between 1964 and 1981, 155 tagged Table l.-Annual number of striped marlin tagged by Cooperative Marine Game Fish Tagging Program striped marlin were recovered-the ma­ Agency, 1957-81. jority by foreign commercial longline NMFS ~ vessels. From recovery records it is pos­ Baja ~ sible to reconstruct migration patterns Cali- Calif. Mazat- Year CDFG WHOI lamia Sur I,m Total and rates. In this study I discuss the fac­ TVPE-FT-1 1957 17 17 Used by CF&G and the NMFS. tors affecting tagging and recovery as 1958 13 13 they relate to migration, and the implica­ 1959 10 10 1960 2 2 tions of the results for fishery manage­ 1961 87 87 C 1962 76 76 ment. l"'~ .....11,.( rlsw. SfJivIC( 7 '­ 1963 18 942 6 973 .~' '(4 JOll l:I Cll, 1964 329 113 9 243 8 702 Tagging Methods and Results 1965 253 52 3 208 7 523 t 0-' ;; 1966 186 47 13 365 15 626 1967 107 31 14 432 166 750 Methods 1968 29 17 749 59 854 1969 1 5 12 406 39 463 According to the tagging instructions, 1970 2 6 24 617 54 703 1971 9 13 827 7 856 TVPE-FM 67 when the bill fish is brought alongside the 1972 7 804 1 812 Used by NMFS, 1963-1969. boat the angler is to insert the dart tag 1973 2 344 3 349 1974 54 603 3 660 beside the dorsal fin. Descriptive litera­ 1975 15 473 1 489 ture illustrating the suggested point of tag 1976 46 576 9 631 1977 37 315 352 insertion is distributed with the tagging 1978 24 557 581 1979 42 458 500 equipment. Because tagging of a large 1980 22 1.142 1,164 active bill fish that cannot be lifted from 1981 60 641 701 ~ the water or partially immobilized is a 896 1,439 420 9.767 372 12.894 difficult task, it is probable that many TVPE-FH-69 or "HO type tags have not been inserted as recom­ Used by NMFS since 1970. mended. When the tagging equipment is dis­ tributed to the angler, the tags are at­ of tag types used in the three areas of tached to a postcard (tag report card) tagging was similar to the above distribu­ which indicates the serial number of the tion percentages, with one exception. A tag (Fig. I). After tagging a fish, the an­ low percentage (4 percent) of FH69 tag gier is requested to complete the tag in­ were used at Mazatl<in, due to a substan­ formation card with the date, location, tial reduction in tagging effort there in the species, estimate of marlin's weight and early 1970's, at about the time the FH69 length, and the tagger's name and ad­ tag was introduced. dress; the angler is requested to return the card to the organization issuing the tag. Tagging Results TAG REPORT CARD Tags used by billfish anglers partici­ Tags were attached to a pating in the Cooperative Marine Game Between 1957 and 1981, 12,894 Tag Report Card having Fish Tagging Program were described by striped marlin were reported tagged in the the same tag number. Squire (1974). Four types of tags have northeast Pacific. This number represents been used for tagging striped marlin in only those tags for which a tag card was the northeast Pacific Ocean (Fig. I). For returned to the agency distributing the tagging conducted under NMFS sponsor­ tags. Table I gives the number of striped ship, less than I percent of the striped marlin tagged by agencies that have pro­ marlin were tagged with type "A" tags. vided tags to cooperating marine anglers. About 7 percent were type "B" or FT-I, During 1963-81 the NMFS program ac­ Maximum tagging effort was in 1980 37 percent type FM67, and 56 percent counted for 10,559 striped marlin tagged (1,164 striped marlin tagged), and low­ type FH69 or "H" type.