Mass production of microalgae in six commercial shrimp hatcheries of the Mexican northwest

A 2-year survey in six commercial shrimp hatcheries of the states of Sonora and Sinaloa, in the Mexican northwest, aiming to investigate the variability of the outdoor biomass production and composition of microalgae showed wide differences in daily mean yields, from 0.68 to 1.71 x 10(12) cells m(-3) and between 23.9 and 73.9 g m(-3) of dry organic biomass. These differences were mostly related to the type of culture containers and consequent differences in light penetration. The best yields were in 0.7 m deep polyethylene tanks and the lowest in 2 m deep concrete tanks with a small surface to volume ratio. Protein, carbohydrate and lipid yields followed the same trends as biomass production and were mostly associated with the design of the culture containers and, in part, with the geographic location of the hatcheries. Variability was high also within laboratories, and this was related to seasonal climatic differences. In Sonora, cell concentrations were negatively related to temperature, but organic biomass production increased with the increase of this climatic variable, probably because of larger cell sizes. In contrast, the data obtained in Sinaloa showed that cell concentration and organic biomass are directly related to temperature and inversely to light. Proteins and lipids were negatively related to temperature in Sonora but not in Sinaloa, where high carbohydrates were associated with low temperatures. Fatty acid profiles were highly variable in all cases and were not associated with the type of culture containers or, with the possible exception of 18C unsaturates, with the geographic location of the laboratories, indicating as probable sources of variability between and within hatcheries either the handling routines or the composition of the growth media. (C) 2003 Elsevier B.V. All rights reserved.