Summer distribution of the southern stock of the Argentine hake (Merluccius hubbsi Marini, 1933) in the nursery area (44°-47°S) in relation to oceanographic parameters (1996-2001)

Summer temperature and salinity data in the nursery ground of the Patagonian stock of Argentine hake Merluccius hubbsi recorded from 1996 to 2001 were analyzed. These oceanographic variables were related to variations in the hake population abundance by means of a general linear model. Mean values and anomalies of bottom temperatures and salinity fields were determined. The most extreme positive thermal anomalies occurred in 1999 and 2000, whereas 1996 was the coldest year. The salinity anomaly was lowest in 1996 and highest in 2000. Argentine hake was found mainly in thermal and saline gradient zones. Juveniles were found mainly within the San Jorge Gulf with temperatures ranging from 8 degrees to 10 degrees C and salinities of 33.2 to 33.6, whereas adults were located inside and outside the gulf, where bottom water temperatures oscillated between 8 degrees and 12 degrees C and salinities ranged from 33.2 to 33.5. Juvenile densities were highest in shallower waters with higher salinities and lower temperatures than those inhabited by the adults. Adult hake were concentrated in the northern part of the Gulf and Camarones Bay, in shallow, relatively warm waters, as well as over the shelf waters off the gulf, where the salinity is low due to the drift of diluted waters from the Patagonian Current. The population distribution did not change in years with striking environmental anomalies.