Climate effects in Abalone and Spiny lobster fisheries in Baja California, Mexico

Abstract

The abalone and lobster fisheries on the western coast of Baja California are economic activities ofgreat importance to the fishing communities settled along that coast. Its historical production from 1950 to 2001shows opposite trends. In the case of the lobster, the catch is upwards, while that of the abalone shows a continuousdownward trend, in addition to presenting minor oscillations. As a hypothesis, it is proposed that both the trendand the oscillations are due to the variation of the fishing effort and the environment acting simultaneously. Therefore, with the aim of weighing the sources of variability, a multiple correlation analysis was applied, considering additionally the seasonal and decennial effects. As environmental variables, indices were used: MultivariateENSO (MEI), Pacific Decadal Oscillation (PDO), Oscillation Gyre Pacific North (OGPN), and local variablessuch as the Upwelling Index (U) and Sea Surface Temperature (SST). The results indicate that, in the case ofabalone, the downward trend of the catch and its variability are better explained by the environment; on the otherhand, in the case of lobster, the fishing effort turned out to be the most important factor. The minor oscillations arealso related to strong El Niño events for both resources.