Malaysia has the potential to be a key seaweed production player in the region if proper management and possible interventions take place. Chapter One analyses the capacity building programs in Malaysia that aim to transform conventional seaweed cultivation techniques to modern seaweed cultivation techniques by applying a scientific approach. Chapter Two studies the marine macroalgae thriving at intertidal rocky shores on the west coast of Portugal, a transition zone where the combined influence of cold waters and warmer waters may favour the development of unique macroalgal communities. In Chapter Three, the authors discuss how problems of environmental deterioration and energy demand could be alleviated by the paradigm shift from fossil to biofuel from marine algae. The chapter elaborates on the unconventional strategies developed for the farming as well as conversion of Ulva rigida to biofuels and biochemicals. Chapter Four discusses the incorporation of macroalgae or macroalgal derived ingredients as a source of both macro-nutrients and micro-nutrients for animal feed production. The biological health benefits of the macroalgal ingredients beyond basic nutrition for the development of functional feed in the aquaculture, the ruminant and the swine sectors are also discussed together with the industrial challenges of its application. To conclude, Chapter Five provides a brief review of seaweed co-culture and its environmental impact on coastal fisheries. First, the current situation and problems facing the coastal fisheries, and the plans to overcome these issues, are discussed. Finally, the positive and negative effects of seaweed culture, role of seaweed co-culture, and the overall environmental impact are addressed.