DISTRIBUTION OF PARTICULATE ORGANIC-MATTER IN BAJA-CALIFORNIA, WEST-COAST OF MEXICO

Spatial distribution of chl-a, proteins and carbohydrates from nano an d microparticles was studied during R V El Puma cruise (10-15 October 1987). Thermally homogeneous surface layer (0-5 m, 25-26-degrees-C) wa s characterized by a significant relationship between nanophytoplankto nic chl-a, and nanoparticulate proteins and carbohydrates (r = 0.95 an d 0.86, respectively), whereas in the thermal stratified layer (5-50 m , 25-16-degrees-C), these relationships were not significant. The same trends were obtained for the relationships between microphytoplankton chl-a, and microparticulate proteins and carbohydrates (r = 0.94 and 0.91, respectively at 5 m layer), despite their lower biomass (5 to 30 % of nanophytoplankton biomass). Results suggested that protein and ca rbohydrate of nanophytoplankton were well represented in the surface h omogeneous layer and accounted for 87 and 60% of the total nanoparticu late biomass respectively. However, in the thermally stratified layer, non-photosynthetic nano and microparticles dominated. This well-diffe rentiated particle distribution corresponds to the presence of the Equ atorial Surface Water, and to the California Current Water at the sub- surface layer.