YELLOWTAIL 



Yellowtail tuna, range from Central California 

 (Monterey Bay) south along the Baja California 

 coast and into the Gulf of California. They are most 

 abundant between Sebastian Viscano Bay, and Mag- 

 dalena Bay, Baja California, where they may be found 

 all year around. California is on the fringe of the 

 population. 



That a large part of the population moves freelv 

 up and down the west coast of Baja California has 

 been demonstrated by 96 of the 341 returns from 

 15,116 fish that have been tagged and released. These 

 fish all moved between 50 and 360 miles from the 

 locality where they were released. Movements of less 

 than 50 miles were shown by 224 recoveries and mi- 

 gratory patterns show that yellowtail go north durmg 

 the spring and summer and south during the winter. 

 Few yellowtail remain in California waters during the 

 winter, thus good angling for this species is depend- 

 ent upon the success and strength of the migratory 

 movement out of the Mexican wintering grounds. 



That yellowtail tuna are all part of one homogene- 

 ous population has been shown by studies of body 

 proportions and counts. Fish from all parts of their 

 range have been compared and no significant diflFer- 

 ences were found. 



Sport Fishing Increasing 



Recreational fishing during 1955 was good, with 

 36,468 yellowtail as the reported catch. This com- 

 pared to the postwar average of 30,386 fish per year 

 by party boats. High catch vulnerability of yellow- 

 tail in areas heavily exploited by anglers has been 

 demonstrated by the high rate of tag returns in such 

 areas. 



Commercial yellowtail fishing, on the other hand, 

 declined to a meager 164,000 pounds in 1955, the 

 lowest commercial catch made since 1916. This de- 

 cline is the result of lack of market demand and not 

 shortage of fish. 



The commercial yellowtail fishery is now regulated 

 by laws and additional restrictions are unnecessary in 

 view of the poor market condition and the biological 

 facts concerning its life history and migrations. 



Progress toward the objectives of this federal aid 

 project have been achieved; the tagging, statistical and 

 most other studies are finished. Nearly completed are 

 studies of food, age and growth, maturity and fecun- 

 dity. Final preparation of the report of this project 

 is being made and upon its presentation the project 

 will be terminated. 



SALTON SEA 



The Salton Sea Project, conducted under contract 

 with the department by the University of California 

 at Los Angeles, with Wildlife Conservation Board 

 funds, progressed exceedingly well and with good re- 



X, 



California corvina being tagged by deparfmenf personnel. 



(Fish and Game Photo by Charles F. Crawford) 



suits being made toward the establishment of a sport 

 fishery in this body of water. 



Project personnel, working from a headquarters 

 established at Fish Springs, Salton Sea in 1954, have 

 been successful in stud\ing conditions at the sea and 

 determining much of the potential that exists there. 

 Physical and chemical factors have been carefully in- 

 vestigated and indicate that the life expectancy of the 

 sea (for a sport fishery) should be at least 30 to 40 

 years. 



An extensive "dead" area (lacking oxygen) has 

 been located over much of the bottom of the sea that 

 lies below 30 feet. This involves about 15 percent of 

 the total area of the sea, but it is anoxic continuously 

 only during the hot summer months. All of the or- 

 ganisms, living in this area during these prolonged 

 periods when oxygen is lacking, die off and are not 

 replaced until cooler winter months when oxygen 

 again becomes available at these depths. 



Worm Is Key to Life Cycle 



The polxchaet worm, Neanthes succinea, has been 

 determined as the most important invertebrate in 

 Salton Sea. The entire fish population, with the ex- 

 ception of the threadfin shad, is dependent upon it 

 for food. Studies have been made upon the barnacle 

 and various planktonic forms found in the sea. Their 

 importance in the sea's development has been investi- 

 gated. 



Of the various fish species now found in the sea, 

 life histories and food habits have been determined 

 when possible. In September, 1955, the threadfin shad 

 was first taken in Salton Sea and the species has since 

 been captured at a number of widel\' scattered locali- 

 ties throughout the area. 



Many Corvina Present 



In the early summer of 1956, personnel investi- 

 gating the covina in Salton Sea, estimated some 100,- 

 000 of these fine game fish inhabit the inland body of 

 water. These represented four \ear classes that had 

 successfully hatched in the sea, the oldest of which 



