Open AccessWinter bloom of some motile phytoplankton under ice cover in a mesotrophic lake: vertical distribution and environmental factors
Author(s) -
Tomasz Lenard
Publication year - 2015
Publication title -
oceanological and hydrobiological studies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.271
H-Index - 22
eISSN - 1897-3191
pISSN - 1730-413X
DOI - 10.1515/ohs-2015-0016
Subject(s) - phytoplankton , water column , biomass (ecology) , environmental science , chlorophyll a , snow , nutrient , ecology , oceanography , biology , botany , geology , geomorphology
The research was carried out in mesotrophic Lake Krasne during winter with thick ice/snow cover. Water samples for biological and physicochemical analyses were collected vertically from the water column. Several phytoplankton groups were identified during the study, however, only two main groups of motile phytoplankton, Cyanophyceae (the dominant species − Planktothrix rubescens) and Cryptophyceae (Cryptomonas spp. and Plagioselmis nannoplanctica), were analyzed in the gradient of nutrients, light and thermal conditions. In the studied water column, values of physicochemical parameters did not vary in a wide range. Nevertheless, high discrepancies were noted in the values of phytoplankton biomass and the concentration of chlorophyll-a which had shallower maxima and deeper minima. Statistically significant relationships were found between the biomass of two main phytoplankton groups, light conditions (PAR) and depth, however, no significant relationships were found between the biomass, biogenic compounds and water temperature. The studies showed that in the winter season with ice/snow cover, cryptomonads and Planktothrix rubescens occupied different ecological niches and the main factor determining their distribution were light conditions. The ice/snow cover probably plays an important role in protection of P. rubescens winter filaments against photoinhibition.