On the occurrence and ecological features of deep chlorophyll maxima (DCM) in Spanish stratified lakes

WHAT IS A "DEEP CHLOROPHYLL MAXIMUM" (DCM)?During the lakes' stratification period, planktonic primary producers, such as some eukaryotic algae and cyanobacteria, can achieve abundance maxima at considerable depths, especially in oligotrophic and mesotrophic lakes (Fee, 1976;Moll and Stoermer, 1982;Margalef, 1983).However, during the mixing period these maxima would not occur because turbulence mixes water preventing the accumulation of phototrophs at certain depths (Reynolds, 1994), as it happens when fall mixing occurs promoting the disappearance of these populations (Abbott et al., 1984).Reynolds (1992) reviewed the key factors that govern the onset, maintenance, and dissipation of vertical structure of the water column and the responses of phytoplankton to this structu-Limnetica, 25(1-2): 453-478 (2006).