Pacific Bonito

Pacific Bonito, Sarda chiliensis

The Pacific Bonito, Sarda chiliensis, whose common Spanish name is bonito del Pacífico oriental, is a member of the Mackerel or Scombridae Family, known collectively as macarelas in Mexico. This fish is also known as the Eastern Pacific Bonito. Globally, there are only four species in the genus Sarda, three of which are found in Mexican waters, one in the Atlantic and two in the Pacific. The fish found in Mexican waters of the Pacific is the subspecies Sarda chiliensis lineolata.

The Pacific Bonitos have elongated rounded fusiform tuna-like bodies that are designed aerodynamically for speed. They are silvery with a dark blue-gray back (being darker on the head), silvery flanks and belly, and a series of five or six stripes running diagonally along their upper back. Their anal and pelvic fins are white; their caudal fin is gray and deeply forked with two small keels separated by one large keel at the base; and their pectoral fins are gray. They have a moderately large mouth equipped with large prominent teeth. Their anal fin has 12 to 15 rays and 6 or 7 finlets. Their first dorsal fin has 17 to 19 spines and their second dorsal fin is followed by 8 finlets. They have 23 to 27 gill rakers on the first arch. The front of their body is covered with large scales.

The Pacific Bonitos are a coastal pelagic schooling species found from the surface to depths of up to 100 meters (360 feet). They reach a maximum length of 1.22 meters (4 feet 0 inches) and 11.3 kg (25 pounds) in weight. They are normally found within 32 km (20 miles) from shore. Young reside around sandy beaches and kelp beds while adults are found in deeper waters. They undergo extensive summer migrations of up to 1,000 kilometers to cooler waters which mirrors the migration of their favorite prey, the Northern Anchovy. They form large schools by size. They feed primarily on Northern Anchovy and other small forage fish, market squid, euphausiids, and other crustaceans and amphipods. They are rapid growing and short lived fish that can reach 51 cm (20 inches) in length within one year. Reproduction is oviparous with each female attaining sexual maturity at two years of age and then spawning several times per year by releasing about 500,000 eggs per annum. Fecundity increases exponentially with size. The eggs and larvae are pelagic. They have a lifespan of less than six years. Very little is generally known about their behavioral patterns.

In Mexican waters the Pacific Bonito are found along the entire West Coast of the Baja and in the extreme southern portions of the Sea of Cortez, however, they will virtually disappear from southern portions of their range when water temperatures are elevated. A fish recently caught caught off the Golden Reef, twenty-two miles east of Puertecitos, Baja California in June 2017 by Chris Wheaton significantly extends the range of this species into the Northern Sea of Cortez.

The Pacific Bonito can be confused with the Black Skipjack, Euthynnus lineatus (5 or 6 horizontal stripes along upper sides; distinguishing black spots on throat); the Skipjack Tuna, Katsuwonus pelamis (4 to 6 horizontal diagonal stripes along upper sides), and the Striped Bonito, Sarda orientalis (8 to 11 broken horizontal stripes along sides; prominent teeth).

The Pacific Bonitos have historically been a heavily targeted commercial species but due to a significant reduction in their population fishing pressure has decreased and they are no longer targeted and have become an incidental commercial catch unless they show up in very large schools. Historically they were harvested in purse seines at levels up to 4.6 million fish and 17,000 tons per annum. They are considered an excellent food fish and sold fresh and frozen. Due to their size, coastal habitats, and horrific fights when hooked, they are also a favorite target of recreational sports anglers along the northwest coast of Baja being caught from boats, piers, jetties, and shores. They are normally caught on live sardines, rapidly trolled feathers, or hoochies, or off the bottom with chrome yo-yo irons. In California they are heavily regulated with length and bag limits. Although their populations have significantly decreased, from a conservation perspective, they are currently classified to be of Least Concern.

Pacific Bonito, Sarda chiliensis. Fish caught from coastal waters off Puerto Los Cabos, Baja California Sur, February 2004. Length: 40 cm (16 inches).

Pacific Bonito, Sarda chiliensis. Fish caught by Captain Jimmy Camacho of Jimmy’s Sportfishing, Puerto Adolfo Lopez Mateos, Baja California Sur, (JimmyHcamacho@gmail.com, 613-114-0761; 612-204-1960) in coastal waters off  Puerto Adolfo Lopez Mateos, Baja California Sur, May 2017.  Length: 40 cm (16 inches).

Pacific Bonito, Sarda chiliensis. Fish caught from coastal waters off Long Beach, California, May 2016. Length: 42 cm (17 inches). Catch, photo, and identification courtesy of Chris Wheaton, Fullerton, CA.

Pacific Bonito, Sarda chiliensis. Fish caught from coastal waters off Long Beach, California, May 2016. Length: 44 cm (18 inches). Note the strong vertical barring pattern indicating that this fish was either in a feeding or breeding mode. Catch, photo, and identification courtesy of Chris Wheaton, Fullerton, CA.

f633-pacific-bonito-4Pacific Bonito, Sarda chiliensisFish caught from coastal waters off Santa Cruz, California, May 2016. Length: 45 cm (18 inches). Catch, photo and identification courtesy of Andrew Hansen, Santa Cruz, CA.

Pacific Bonito, Sarda chiliensis. Fish caught off the Golden Reef, 22 miles east of Puertecitos, Baja California, June 2017. Length: 46 cm (18 inches). Catch, photo, and identification courtesy of Chris Wheaton, Fullerton, CA.  This is  a significant range extension for Sarda chilensis into the Northern Sea of Cortez.