抄録
We analyzed the optical and hydraulic conditions of phytoplankton population competition based on the characteristics of antenna pigment absorption. From the analytical results of competition between th two types of antenna pigment, we found that the underwater light conditions in which short-wave blue or green light is superior (e. g. in clear water bodies), and the hydraulic conditions in which the ratio of mixed depth to euphotic depth is greater, are favorable for phycoerythrin-rich type (PE type) cyanobacteria. Conversely, under the optical conditions such as those in reservoirs where water tends to have lower transparency compared to oceans, it is assumed that shallow mixed depth can make phycocyanin-rich type (PC type) cyanobacteria more advantageous than PE type. Furthermore, for large-colony PC type cyanobacteria (LCPC) such as bloom-forming Microcystis, a mixed depth of several times the euphotic depth is the its critical depth. Therefore, LCPC requires shallow mixed depth from the optical point of view.
