Are they in a bio-available form? Wouldn't the phenols and phyto-chemicals be detrimental to absorption?
The supplement contains DHA (Docosahexaenoic acid) produced from algae.
As far as I know the long-chain omega-3 fats in fish oil originate from algae. In the sea Algae are at the bottom of many food chains and the omega-3 fats they produce work their way up to be concentrated in larger carnivores such as fish.
Producing DHA from algae is not complicated however each algal cell only produces a tiny droplet of lipids. You have to grow up a huge amount of algae to get much oil but this is less of a problem now with modern growing systems if you use the right kind of algae.
If you separate the oil from enough algae you have quite a pure source of DHA.
Producing quantities of EPA from algae is much harder but I understand people are working on solving this problem.
When this process becomes cheap enough I think it will be used to replace most fish oil supplements. I might help to stop us fishing the worlds oceans until they are empty. There isn't enough fish left now to provide everyone with fish oil.