Photoreactivation of far U.V. damage in the dinoflagellate Peridinium cinctum

Phytoplankton responses to human impacts at different scales

“…Table 3 Results of univariate test (mixed model with enclosures as random effect nested with light) of APP biovolume in both sets of microcosms (with and without nanoplankton), and abundance of APP size fractions, total phytoplankton and main population biovolumes measured at time 0, 1 and 2 in microcosms in PAR and UVR ? The latter case could be explained by the ability of Peridinium to repair damage, demonstrated when it is under alternate UVR supply (Hayhome et al, 1981). In this study of a mid altitude and low latitude lake, when the existing plankton were exposed to UVR addition, not only small cyanobacteria (picocyanobacteria) were more affected than nanoplankton but also, the three dominant populations of nanoplanktonic algae exhibited different behaviour: the smallest ones being the most affected by an increase in UVR (C. comensis) which reduce their population density; while C. meneghiana, that is larger in size, stopped growing after UVR dose; and P. umbonatum, although it grew under UVR, it did it less than without this radiation.…”