Effects of ENSO 1997?1998 on the distribution of small pelagic fish off the west coast of Baja California
Changes in the Small Pelagic Fish (SPF) densities and distribution during ENSO 1997?1998 were found from observations made between 1994 and 2001 along the northwestern coast of Baja California, Mexico. Results showed that temperature and variables associated with the surface mixing processes had an effect on the SPF shoal behaviour and distribution. Between September and December 1997, acoustic density showed maxima that were accentuated in the neritic and slope zones and with a wide depth interval. The results suggest that in the presence of climate anomalies like ENSO 1997?1998, SPF are concentrated in specific areas not influenced directly by these anomalies and therefore available to fishing in considerable abundance and vulnerable to a high fishing scheme. Our recommendation for SPF-fishery management is to regulate the fishing during these anomalously warm periods. Finally, it is important to investigate more about fishing scenarios during climate anomalies to contribute to an improved concept for a sustainable fishery.
Keywords: ENSO, El Nino Southern Oscillation, small pelagic fish, SPF, fishery management, shoaling, thermocline, mixed layer, sustainability, Mexico, fish densities, fish distribution, fishing regulation, climate anomalies