A short video about algae that grow in brackish water and can produce biofuel feedstock
A short video about algae that grow in brackish water and will only take around 5000 square kilometres. The researchers at the Unviersity of Texas at Austin estimate that it would take 820,313 square miles of corn or 234 000 square miles for switchgrss (that's most of Texas) or 5000 square miles using Algae. Not only that but the algae will help to fix nitrogen.
Looks pretty optimistic to me. Take a look for yourself and make your mind up.