Identify the incorrect statement regarding algae:
(1) At least a half of the total carbon dioxide fixation on earth is carried out by algae through photosynthesis.
(2) Around 70 species of freshwater algae can be used as food.
(3) Certain marine brown and red agae produce large amounts of hydrocolloids (water holding substances), e.g., algin (brown algae) and carrageen (red algae) which are used commercially.
(4) Agar, obtained from Gelidium and Gracilaria are used to grow microbes and in preparations of ice-creams and jellies.