Primary producers

Japanese: 一次生産者 - いちじせいさんしゃ

…Plankton can be broadly divided into two groups: phytoplankton, which live a floating life, and zooplankton. Phytoplankton are autotrophic organisms that grow by synthesizing organic matter as living organisms through photosynthesis, and are the most important primary producers (basic producers) in lakes and ponds. As mentioned above, sunlight that penetrates into the water attenuates with depth, so phytoplankton can only photosynthesize in the water near the lake's surface, the lower limit of which is the depth at which the underwater luminosity falls to 1% of the value at the lake surface. …

From [Ecosystem]

…the starting point of biological production in an ecosystem. Also called primary producers or primary producers. Producers are mainly green plants (higher plants and algae including cyanobacteria) that have the photosynthetic pigment chlorophyll, which absorb solar energy and synthesize carbohydrates from carbon dioxide and water. …

*Some of the terms mentioned in the description of "primary producers" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

Japanese:

…プランクトンは，一生浮遊生活をする植物プランクトン，動物プランクトンの2群に大きく分けられる。植物プランクトンは，光合成により生体としての有機物を合成し増殖していく独立栄養生物であり，湖沼における最も主要な一次生産者(基礎生産者)である。先に述べたように，水中に透入した太陽光は水深とともに減衰していくので，植物プランクトンが光合成を行えるのは，湖の表層近くの水中に限られ，その下限は水中光度が湖表面の値の1％に低下する深度にあたる。…