IR Home
AME
Home
Editors
Forthcoming
Information
Subscribe
Journals
Home
MEPS
AME
CR
DAO
ESEP
Search
Subscribe
Book Series
EE Books
Top Books
Order
Discussion Forums
Home
Research
Endangered Species Programs
Institutions
International Ecology Institute
Eco-Ethics International Union
Foundation
Otto Kinne Foundation
| |
AME 26:283-294 (2002)
|
Abstract
|
![](../../../../images/hline.gif)
Distribution of mycosporine-like amino acids and photoprotective carotenoids among freshwater phytoplankton assemblages
Isabelle Laurion1,*, Andrea Lami2, Ruben Sommaruga1,**
1Institute of Zoology and Limnology, University of Innsbruck, Technikerstr. 25, 6020 Innsbruck, Austria
2National Research Council, Institute of Hydrobiology, Verbania-Pallanza, Italy
*Present address: Institut des Sciences de la Mer, Université du Québec à Rimouski, 310 Allée des Ursulines, Rimouski, Québec G5L 3A1, Canada **Corresponding author. E-mail: ruben.sommaruga@uibk.ac.at
![](../../../../images/hline.gif)
ABSTRACT: Abstract: Phytoplankton have evolved different strategies to minimize the potential damage caused by solar ultraviolet radiation (UVR), including the synthesis of UV-absorbing compounds that act as sunscreens and carotenoids that provide protection
against photooxidative stress. The concentration and qualitative composition of mycosporine-like amino acids (MAAs) and photoprotective carotenoids (PPCs) were investigated in natural phytoplankton assemblages of 26 lakes located below and above the
treeline in the Alps and the Pyrenees. Among these lakes, exposure to UV varied because of differences in the incident spectral dose, water column transparency, stratification, and maximum depth. Seven MAAs were identified, but the most abundant were
shinorine (lmax = 334 nm) and palythine (lmax = 320 nm). The highest concentrations of MAAs (up to 9.6 µg [µg chl a]-1) and PPCs (up to 0.6 µg [µg chl
a]-1) were found in the clearest and shallowest lakes, while phytoplankton from lakes with low UV transparency generally presented low values. However, phytoplankton of some clear lakes located at high altitude did not have high
concentrations of these compounds. Consequently, underwater downwelling UVR, UV water transparency, or lake altitude explained only a low percentage (<26%) of the variability among lakes in MAA and PPC concentration. Within the water column, the
concentration of MAAs decreased in most cases with depth, suggesting their photoprotective role. Our results indicate that MAAs and PPCs are widespread among lake phytoplankton assemblages and suggest that other environmental factors besides UV
exposure are important in regulating their synthesis.
KEY WORDS: MAA · Sunscreens · Ultraviolet radiation · UV · Solar radiation · Photooxidative stress · Alpine lakes
Full text in pdf format
![](../../../../images/hline.gif)
Published in AME Vol.
26, No. 3
(2002) on January 18
Print ISSN: 0948-3055; Online ISSN: 1616-1564.
Copyright © Inter-Research, Oldendorf/Luhe, 2002
|