The invention provides methods of cultivating microalgae photoautotrophically outdoors to prepare concentrated microalgae products containing eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) docosahexaenoic acid, two long-chain polyunsaturated fatty acids found in fish oil that are very important for human and animal health. It also provides concentrated microalgae products containing EPA and DHA and purified lipid products containing EPA and DHA purified from microalgae.
