Primary producers are organisms with the ability to convert inorganic materials into organic materials to be used as food. They are the basis of all food webs. In the soft shore ecosystem, the flora and algae (both micro- and macroscopic) play a significant role as primary producers.
The following is a list of representative species from each group of primary producer that can be found in Hong Kong.
Macroalgae are a diverse group of multicellular plant-like organisms. They share some physiological characteristics with plants, such as the ability to photosynthesize through light harvesting pigment, but they are not regarded as plant. They should be distinguished from seagrass, which is the flowering plant with vascular tissues for transportation of water and nutrients. Macroalgae commonly found in the marine environment are called seaweed. Some particular species of seaweed, such as the green algae (Ulva spp.), could be found at the soft bottom of estuaries. Occasionally, some brown algae (Colpomenia sinuosa) could be found in the relatively saline environment in the estuarine area.