In situ study of relative electron transport rates in the marine macroalga <Emphasis Type="Italic">Fucus vesiculosus</Emphasis> in the Baltic Sea at different depths and times of year |
| |
Authors: | N G A Ekelund C A Nygård R Nordström A M Gylle |
| |
Institution: | (1) Department of Natural Sciences, Mid Sweden University, 851 70 Sundsvall, Sweden |
| |
Abstract: | The brown alga Fucus vesiculous is one of the few marine species in the Baltic Sea. Fucus vesiculosus shows high morphological and physiological variability as a response to its environmental conditions. The salinity in the
Baltic Sea is 4–5 psu, compared to 35 psu in the Atlantic. Photosynthesis of algae is usually measured after collection and
transportation to constant culture conditions. However, in this study, relative photosynthetic electron transport rates, calculated
from chlorophyll a fluorescence parameters were compared in algae collected from 1 and 4 m depths by SCUBA divers. Measurements of light response
curves from the same individuals of F. vesiculosus at different depths and times of the year have, to our knowledge, not been made previously. Measurements were performed on
four different occasions during the spring of 2005 (25 February, 3 and 29 April, and 26 May) in the Baltic Sea, using rapid
light curves generated with a Diving PAM. In addition, samples were collected for photoinhibition studies in the laboratory.
The light response curves obtained in situ at 1 and 4 m depths for F. vesiculosus showed lower values of light saturation with depth. When algae from 1 and 4 m depths were exposed to high irradiances of
photosynthetically active radiation (1,400 μmol photons m−2 s−1), algae from 1 m depth showed a higher degree of photoinhibition in comparison to algae from 4 m depth. |
| |
Keywords: | Diving PAM Fluorescence Photoinhibition Photosynthesis |
本文献已被 SpringerLink 等数据库收录! |
|