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Includes all arrivals as reported by express and rail terminals, and truck receipts as reported by wholesale dealers including smokers.

2/ Data for individual cities are as of the last Thursday of the month, except those for Boston which are for the last Wednesday of the month. Data on United States holdings by various species and by geographical areas are as of the first of the month.

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1.6

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FISHERY MARKET NEWS

JUNE 1944
CONTENTS

OBSERVATIONS ON THE SHARK FISHERY IN THE CENTRAL PART OF THE GULF OF CALIFORNIA
WITH RECORDS OF VITAMIN POTENCY OF LIVER OILS AND WITH KEYS TO THE IDENTIFICATION
OF COMMERCIALLY IMPORTANT SHARKS, by Lionel A. Walford

FEDERAL ORDERS, PURCHASES, AND REGULATIONS:

OCF--Large pack of Maine sardine expected

OPA--Correction made to Amd t. 30, MPR-418

Region VIII issues price controls on local species

Amd t. 4 to MPR-507 effective May 25

Amdt. 17 to MPR-364 issued May 1

Amdt. 18 to MPR-364 effective May 20

Canned fish flake prices increased

Canned fish trade point values suspended

Fish meal prices revised May 22

Selective Service System--Revises orders affecting occupational classifications
WFA--Seasonal cold-storage freezer space peak passed

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FISH AND WILDLIFE SERVICE

FISHERY MARKET NEWS

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A REVIEW OF CONDITIONS AND TRENDS OF THE COMMERCIAL FISHERIES

PREPARED IN THE DIVISION OF FISHERY INDUSTRIES

A. W. Anderson, Editor

C. R. Lucas, Associate Editor

SERVICE

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MARKET NEWS
MARKETING

Applications for FISHERY MARKET NEWS, which is mailed free to members of the fishery industry and allied interests, should be addressed to the Director, Fish and Wildlife Service, United States Department of the Interior, Washington 25, D. C.

June 1944

The Service assumes no responsibility for the accuracy of material from outside sources.

Washington 25, D. C.

Vol. 6, No. 6

OBSERVATIONS ON THE SHARK FISHERY IN THE CENTRAL PART OF THE GULF OF CALIFORNIA

with

RECORDS OF VITAMIN POTENCY OF LIVER OILS

and with

KEYS TO THE IDENTIFICATION OF COMMERCIALLY IMPORTANT SHARKS

By Lionel A. Walford*

In recent years, the fisheries for sharks on the west coast of Mexico have changed character and purpose. Whereas, formerly shark oil was utilized only locally for the manufacture of soap and for processing leather, since about 1938, it has found a new market in the United States because of its Vitamin A content. The fishery has consequently grown to large proportions. Catch figures are not available, but some notion of the volume may be obtained from the fact that 385,000 pounds of livers were produced in the Mazatlan Consular Area alone in 1942 up to July 31 (Fishery Market News, 1942, S 1).

Published knowledge is almost totally lacking as to the kinds of sharks caught, as to their geographic and seasonal distribution, and as to the magnitude of Vitamin A potencies of their livers. To arrive at such knowledge would require observations at many places, so as to sample adequately the entire geographic range of all species during all seasons.

An opportunity to make observations and collections at San Marcos Island, Lower California, was offered by Mr. J. A. McCarthy, through Mr. Otis Small of the Pacific Portland Cement Company, which in normal times utilizes the output of a gypsum mine there and encourages a local shark fishery. Accordingly, the writer spent from September 16 to October 12, 1942, of which one week was in Guaymas, the remainder at San Marcos Island, taking full advantage of the generously offered facilities of the Pacific Portland Cement Company. The following information was obtained from data collected there, and from conversations with American buyers, Mexican dealers and fishermen.

The shark fisheries of the Pacific Coast of Mexico is a peculiarly diffuse industry. There is hardly a bay or sheltering island in the Gulf of California or on the open coast that does not support one or more shark fishing camps. Though individually these are small enterprises, the sum of their effort is impressive.

Shark fishing camps are composed of several men, sometimes with their families, equipped with sailing dugouts or skiffs and necessary fishing gear, Two to several men operate one boat. Boats and gear may be owned by the fishermen themselves, or wholly or in part by investors living ashore. Fishermen put to sea daily, weather permitting, leaving early in the morning and returning in mid-afternoon with their fare of liver, flanks, and fins of sharks. These are salted, the liver stored in cans, the flanks baled, the fins piled or sacked. From time to time, the collected products are hauled by burros or sailed in canoes to various ports visited by freight boats or served by railroads. At the larger ports, like Mazatlan, Mansanillo, Topolobampo, and Guaymas are refrigeration facilities. Fishermen operating from these ports land livers fresh, which are then iced, frozen or chemically-treated for shipment to the United States.

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Several Mexican wholesale companies deal in shark livers; also several American companies or individuals buy livers outright or act as agents for Mexican dealers. Activity of these is in a constant state of flux, depending on the United States' demand for Vitamin A.

Over forty species of sharks occur along the west coast of Mexico. These vary greatly in potency of Vitamin A in their livers from those that are worthless in this respect to those that, at times, run up into the high potency brackets. Moreover, each species varies as to potency of liver. Large sharks are said to be more potent than smaller ones; males more potent than females; those living in deep water more potent than those living in shallow water. A considerable variety of species are caught for livers, with a wide range of potencies.

There is a great variation from place to place and from season to season in species available, in their sizes, and in sex ratio. Consequently, observations made at any one locality can apply only to that locality and for the time of year the observation was made. Thus, any significant biological study of Mexican sharks should make ample provision for observations over a large area and over a considerable period of time.

In the region of San Marcos Island and Guaymas, most sharks are caught with a gear called the "zimbra," which is merely a long set line. It consists of an anchor line, at San Marcos typically 600 meters long, with a buoy at its upper end, and anchor at the lower, followed by about 150 meters of additional line. To the latter length are fastened short lines at intervals of about three meters. Each of these consists of a length of rope about one meter long, followed in order by a swivel, a chain about one-half meter long; and to this is attached a large hook, with a shaft about 20 centimeters long. The lines are of about one-half inch rope. The hooks are baited with fish eight to ten inches in length, the bait at San Marcos at this time being mostly Haemulids (Haemulidae--the Grunts). This gear is set for as long as three days at a time, and since the water is cold at the depths fished there is no danger of spoiling bait or catch in this interval. The zimbra is hauled in by hand, old bait replaced, the catch removed and the line reset. Fishermen usually butcher the sharks in the boat, if there is room, and throw the remaining carcasses on to beaches, preferably well away from their camps.

Some additional sharks are caught with other gear. Boats usually carry a spear or two, for harpooning any sharks seen near the surface. This is particularly useful for capturing hammerheads. Gill nets are used by some fishermen, but have not been markedly successful in the past, being unsuitable for the very large sharks that abound in Mexico. A gill net set and pulled daily at San Marcos Island caught nothing important during the period of observation. On two occasions, it was badly torn by big fish that had escaped. Also, since it had to be set in relatively shallow, hence warm, water, fish caught tended to spoil. Since these observations were made, however, it has been reported that gill nets have recently been used with some success in areas southward of Guaymas.

The biological data collected during the two and a half weeks at San Marcos Island consisted in the examination of 36 specimens. Among these, seven species were distinguished. A sample of liver was taken from each fish examined, preserved in a soda ash-formaldehyde solution, and sent to the technological laboratory of the U. S. Fish and Wildlife Service at Seattle. The assays are given in Table I. It is to be observed that three-fourths of the specimens were of the genus Eulamia, of which more than half were Eulamia lamiella. Among scores of carcasses examined on beaches, at least 90 percent seemed to be E. lamiella, the remainder mostly hammerheads (Sphyrna diplana). Thus, it appears that the most important sharks at San Marcos during the whole year are the two latter species. Fortunately, these are two of the richest in Vitamin A.

While it is impossible to judge of the abundance of sharks from observations made during this short stay at one point of the Gulf of California, fishermen and dealers uniformly expressed the opinion that the supply of Mexican sharks is exceedingly large. There seems no reason to doubt that the population is large, but to form a reliable estimate would take a vastly extensive survey.

The Mexican sharks are not very well known to science. Owing to their large size, they are poorly represented in museums, and then only by immature specimens. Many of the different species look very much alike, and are difficult to identify. Doubtless, several have yet to be described and named, as is attested by the frequency and consistency with which fishermen described sharks which they sometimes catch, and which are not familiar to the writer.

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