Algae such as blue greens and chlorophycean members, many higher plants and many photosynthetic bacteria are the producers. These trap the solar energy and prepare complex organic compounds. Producers are of two kinds.
Macrophytes and Phytoplanktons. Many large hydrophytes such as Trapa, Typha, Elecoharis, Vallisnaria, Nymphaea, Chara, Nitella, Potomogeton and a whole range of other green aquatic plants belong to the category of macrophytes. Free floating algae such as Chlamydomonas, Scendesmus, Pediastrum, Chlorella, Vovox. Diatoms, blue green algae are called phytoplanktons.