Shortfin Mako

fieldmarks: Spindle-shaped body, long, acutely conical snout, large bladelike teeth without cusplets or serrations, pectoral fins rather narrow-tipped and with anterior margins less than head length, large first dorsal fin and minute, pivoting second dorsal and anal fins, strong keels on caudal peduncle, no secondary keels on caudal base, crescentic caudal fin, ventral surface of body white. Body moderately slender. Snout acutely conical; eye moderately large; cusps of first upper anterior teeth with incomplete cutting edges, in young and small adults, tips of anterior teeth strongly reflexed, cusps narrower and more oblique. Pectoral fins moderately long and broad, shorter than head. Colour: underside of snout white.

Coastal and oceanic, temperate and tropical.Western Atlantic: Gulf of Maine to southern Brazil and ? northern Argentina, including Gulf of Mexico and Caribbean. Eastern Atlantic: Norway, British Isles and Mediterranean to Ivory Coast, Ghana, and South Africa. Indo-West Pacific: South Africa, Red Sea to Pakistan, India, Indonesia, the Koreas, Japan, Russia (Primorsk Kray), Australia (Queensland, Tasmania, South and western Australia, Victoria, New South Wales), New Zealand, New Caledonia, Fiji. Central Pacific: from south of Aleutian Islands to Society Islands, including Hawaiian Islands. Eastern Pacific: southern California and exceptionally Washington (USA) to central Chile.

Maximum about 394 cm, possibly to 4 m; males maturing at about 195 cm and reaching at least 284 cm; females maturing at about 280 cm and reaching at least 394 cm; size at birth between 60 and 70 cm. Two published exponential length-weight curves are at slight variance: WT = 4.832 x 10-6 TL3.10 (Stevens, 1983, N = 80, TL = 58-343 cm, Australia). WT = 1.193 x 10-6 TL3.46 (Guitart, 1975, N = 23, TL = 160-260 cm, Cuba). A log curve, log WT = -4.608 + 2.925 log TL (cm), was published by Strasburg (1958) for this species using Central Pacific specimens.

The shortfin mako is a common, extremely active, offshore littoral and epipelagic speciesfound in tropical and warm temperate seas but seldom occurring in waters below 16°C. This shark occurs from the surface down to at least 152 m.The peregrine falcon of the shark world, the shortfin mako may be the fastest shark and one of the swiftest and most active fishes. It is famed as a jumper, leaping several times its length from the water, and is capable of extreme bursts of speed when hooked and in pursuit of prey. For a shark of such great fame, particularly in the angling literature, knowledge of its biology is surprisingly sketchy. The shortfin mako, in the extreme northern and southern parts of its range, has a tendency to follow movements of warm water masses polewards in the summer. General movements of this shark are not well known. This species is ovoviviparous and a uterine cannibal, with 4 to 16 young in a litter. The shortfin mako is primarily an eater of other fishes, with a wide variety of prey including mackerel, tuna, bonito, and other scombrids, anchovies, herring, grunts, lancetfish, cod, ling, whiting and other gadids, Australian salmon (Arripis ), yellowtails and other carangids, sea bass, porgies, swordfish, and other sharks (blue sharks, Prionace, gray sharks, Carcharhinus, and hammerheads Sphyrna ), but also sea turtle heads, a 'porpoise' (probably a pelagic dolphin), and also squid, salps, and occasional detritus. Surprisingly, marine mammals (in the form of pelagic dolphins ) are rarely reported in the diet of the shortfin mako, but they may be expected particularly in large individuals of the species. Very large shortfin makos over 3 m long have broad, more flattened and triangular upper teeth, perhaps more suitable for dismembering large prey than the awl-shaped teeth of smaller makos.

This is an important species for longline fisheries where it occurs, because of its high quality meat, and also is a prime game fish prized by sport anglers. Catch statistics for this species have been reported to FAO only from USA in area 21 (Northwest Atlantic). Statistic series starts in 1987 and ends in 1995 with a peak (71 t) in 1993. The total catch reported for this species to FAO for 1999 was 896 t. The countries with the largest catches were Chile (379 t) and Spain (335 t). The meat is utilized fresh, frozen, smoked and dried salted for human consumption; the oil is extracted for vitamins; the fins used for shark-fin soup; the hides processed into leather and the jaws and teeth used for ornaments.This shark is caught in gillnets as well as on pelagic longlines and hooks and lines . There are several data sets that could be used to evaluate the impact of fishing on shortfin mako sharks but their limited quality and sometime conflicting information do not provide a clear picture of the situation. The shortfin mako is a prime fish for sport anglers and a common bycatch in commercial tuna and swordfish fisheries worldwide (Bonfil 1994). Because its meat is highly valued for human consumption, bycatches of shortfin makos are often landed. Sport fishing for shortfin makos is widespread in both coasts of the USA and increasing in effort in California (Mooney-Seus and Stone 1996). The shortfin mako is more commonly caught by swordfish longliners than by tuna longliners in the US Atlantic coast (Hoey 1983). Hoey and Scott (1997) report an increasing trend in shortfin mako CPUE over the period 1957-1995 in the Western North Atlantic, but warn against possible errors due to the quality of data and the standardisation procedure used to join dissimilar data sets. A lack of trend in mako shark CPUE is evident in the period 1986-1997 for the sport fishery off Virginia-Massachusetts (Brown 1998), while logbook data from US commercial longliners shows a strong decline from 1.38 to 0.36 sharks per 1000 hooks between 1986-1997 (Cramer 1998). Although the latter two data sets pertain to a mix of two mako species, most of the catches are shortfin makos. According to Bonfil (1994) the Spanish longline fleet caught about 750 t/y of shortfin makos in the Atlantic Ocean and Mediterranean Sea in the early 1990s. Off California, early juvenile shortfin makos were targeted by a short-lived experimental drift longline fishery and are a very welcomed bycatch in the driftnet fishery for swordfish (Cailliet et al. 1993). Up to 475 t of shortfin makos were taken jointly by these fisheries in 1987, and although CPUE did not show a declining trend concerns over the heavy exploitation of immature fish prompted the closure of the experimental longline fishery in 1992 (O'Brien and Sunada 1994). Bonfil (1994) estimated that the total bycatch of shortfin makos in the extinct high-seas driftnet fisheries in the N Pacific in the early 1990s was about 360 t/y. This species is apparently very common in the tuna fisheries of Indonesia: unconfirmed reports indicate that landings of shortfin makos from Indonesian waters attained 5,200 t in 1995 and that the estimated potential is about 16,000 t/y (Priyono 1998). The Brazilian longlinning fleet based in Santos landed between 13.3 and 138.3 t of shortfin makos annually between 1971 and 1990 (Costa et al. 1996). Despite increasing fishing effort during this period, the CPUE of shortfin makos has remained relatively stable with an initial slight decreasing trend followed by a slight increasing trend. Cliff et al. (1990) report no trend in the catch rate of shortfin makos after 23 years in the beach protection programme of Natal, SA, and attribute this to negligible mortalities of this species by the meshing programme. Conservation Status : According to Smith et al. (1998), the shortfin mako has a mid-range intrinsic rebound potential. This, together with its worldwide distribution and relative high abundance in some areas probably offers a safeguard over the conservation of the species at the global level. However, as any other elasmobranch it can be easily overfished if not carefully managed. Its exploitation in nursery areas is particularly worrisome. The shortfin mako has been preliminarily considered a Lower Risk/Near Threatenedspecies for the IUCN Red List (Stevens in press b). However, this classification is awaiting IUCN Shark Specialist Group consensus. Mooney-Seus and Stone (1996) consider this species as Vulnerable toReduced in the US Atlantic and Data Deficientelsewhere. Additional information from IUCN database Additional information from CITESdatabase