The hlgh biological productivity of the Hurnboldt Current System (HCS) off Chile supports an annual fish catch of over 7 mill~on t. The area is also important biogeochemically, because the outgassing of recently upwelled water is modulated by contrasting degrees of biolopcal activity. However, very few field measurements of primary production and planktonic respiration have been undertaken within the Eastern Boundary Current (EBC) system off Chile. In this study an estimate of primary production (PP) and surface planktonic commun~ty respiration is presented from several research cruises in the HCS and adjacent oceanlc areas. The highest production levels were found near the coast correlating closely with known upwelling areas. Both gross primary production (GPP) and community respiration (CR) showed important spatial and temporal fluctuations. The highest water column integrated GPP was measured in the southern and central fishing area (19.9 g C m-2 d-l) and off the Antofagasta upwelling ecosystem (9.3 g C m-' d-'). The range of GPP agrees well with values reported for Peni (0.05 to ll

A study was made of growth and carotenogenesis in eight strains of the green alga Dunaliella salina collected from salt ponds at Salar de Atacama (23°30' S; 68°15' W) and Antofagasta (23°39' S; 70°24' W), Chile and kept in unialgal cultures at the Laboratorio Cultivo de Algas, University of Concepcion. The algae were grown in Erdschreiber medium supplemented with 12.5 % w/v NaCI, under a continuous photon flux density of approximately 150 pmol m 2 s-I at 25 + 4 C without aeration. When growth reached the stationary phase, the amount of NaCl was increased to 25%. Total carotenoid content was measured during the exponential growth phase and 20 days after the addition of salt. Strain CONC-001 (Laguna La Rinconada, Antofagasta) exhibited the highest growth rate (k = 0.32 div d-1) and the lowest total carotenoid content (7.2 and 13.7 mg 1-at 12.5 and 25 % NaCl, respectively). Strain CONC-007 (Salar de Atacama) had the lowest growth rate (k = 0.14 div d-') and yielded the highest total carotenes per volume unit (23.1 and 35.6 mg 1-at 12.5 and 25% NaCl) and per cell (ca. 42 pg at 25% NaCl). Total carotenoid synthesis did not increase in strains CONC-001 and CONC-006 with the increase of salinity. These strains had the greatest increase of total carotenoid-to-chlorophyll ratio (4.5-and 9.3-fold, respectively). The seven strains from Salar de Atacama had higher total carotenoid contents than the strain from Antofagasta. Cell size also varied. Strain CONC-001 cells were smallest; strain CONC-006 had the largest cells. There was an inverse correlation between maximum cell density and mean cell size.

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