In his post for Livestrong.com, Dr. Joseph Pritchard tells us, "The omega-3 fatty acids that humans get from the fish they consume primarily come from the algae that the fish eat, according to Eurkalert.org. Fish consume algae and then retain the omega-3 fatty acids in their bodies. Unfortunately, it is difficult to keep pace with the demand for fish oil because fish stocks that provide this oil are being depleted, and farmed fish do not provide sufficient amounts of omega-3 fatty acids, according to the British Medical Journal in the article "Omega 3 Fatty Acids and Cardiovascular Disease." The farming of microalgae, both as animal feed rich in omega-3 fatty acids and as a direct source of "fish oil," has been proposed.
"One microalgae that has attracted a lot of interest as a commercially viable source of EPA and DHA is Pavlova lutheri and efforts are being made to cultivate it to maximize the amount of EPA and DHA it produces, according to the Marine Biology journal in the article " Optimization of Omega-3 Fatty Acid Production by Microalgae: Crossover Effects of CO2 and Light Intensity under Band Continuous Cultivation Modes." The efficacy of EPA and DHA from microalgae is comparable to that of the DHA and EPA from fish oil, according to "Current Diabetes Reviews" in the article "Omega-3 Fatty Acids for Nutrition and Medicine: Considering Microalgae Oil as a Vegetarian Source of EPA and DHA."
For now, algae oil is significantly more expensive, and typically you'll need to take a larger amount of the oil to get the same amount of DHA and/or EPA as in fish oil. However, the benefits for fertility, pregnancy, and the health of the fetus and baby make this a very worthwhile supplement for vegans to consider.
To learn more about the benefits of fish oil for fertility, pregnancy and baby:
To read Dr. Pritchard's article in its entirety: