Assessment of the round herring (Etrumeus teres ) and Monterrey (Sardinops sagax caerulea ) sardine population in the Gulf of California.

As a result of the ichthyoplanktonic research realized along the Gulf of California in March, 1981, the biomass of the reproductive population of the Monterrey sardine (Sardinops sagax caerulea ) and round herring (Etrumeus teres ) was calculated, also the spawning areas were determined as well as their geographic distribution. Spawning for both species occurs in a temperature range of 16 degree -20 degree C with salinity rates around 35.2 ppt. The eastern gulf coast, specially Agiabampo Bay is considered an important spawning zone. Adult biomass for round herring was 295 x 10 super(3) MT with a potential yield of 74 x 10 super(3) MT and instantaneous mortality of Z = 0.50. For Monterrey sardine the estimate was 343 x 10 super(3) MT with a potential yield of 85 x 10 super(3) MT and a mortality of Z = 20. The estimates were based on the total number of hatched eggs in the surveyed area.