Responses of periphyton morphology, structure, and function to extreme nutrient loading.

Periphyton have been widely applied in aquaculture systems, however, little information is available on how periphyton respond to such high nutrient levels in water. Thus, changes in the morphological characteristics, community structure, and metabolic function of periphyton under high eutrophic waters were evaluated. The results indicated that the morphology of periphyton was affected by increasing the nutrient concentration of water, which shifted the micromorphology of periphyton from spheriform to filamentous. The periphyton under higher water nutrient levels were able to utilize more carbon source types. Additionally, higher water nutrient levels increased the bacterial and protozoal proportions in periphyton. This study fills the gap in knowledge about the responses of periphytic communities to extremely eutrophic waters. It provides valuable information on the full understanding of the periphyton-nutrient relationship in aquaculture systems, which is beneficial for regulating the microbial species or communities in periphyton by manipulating the nutrient levels in water.