Journal ArticleDOI
Influence of UV radiation on the photosynthesis of Arctic macroalgae in the field
TLDR
Algae from the sublittoral zone had problems coping with the natural UV radiation in shallow water, whereas those from the intertidal zone were acclimatized to the unfavourable UV /PAR conditions.Abstract:
The photoinhibition in brown and red macroalgae from Spitsbergen (79°N, 12°E) was investigated to study the effects of UV under balanced UV /photosynthetically active radiation (PAR) conditions. Algae were collected from different depths and exposed to natural solar radiation. Various parts of the UV radiation spectrum were successively cut off by filters absorbing wavelengths of less than 295 nm, less than 320 nm and less than 400 nm. The samples were covered with these filters and exposed to daylight 10 cm below the water surface in outdoor tanks near the shore supplied with running seawater. PAR and UV radiation were continuously measured during the experiments. The degree of photoinhibition was observed during the course of the day by measuring the in vivo fluorescence of photosystem II ( F v F m ). In addition, the transmittance of the water body of the Kongsfjord (Spitsbergen, Norway) related to the UV and PAR wavelength ranges was determined. Even on a sunny day in August, only relatively low fluence rates of UVA (approximately 13 W m−2), UVB (approximately 0.14 W m−2) and PAR (approximately 1100 μmol m−2 s−1 ) were measured in the air at noon due to the low position of the sun at this high latitude. The UV transmittance of the water body in the fjord was also low. As a result, UV stress occurred only in seaweeds growing in the intertidal zone or in shallow water. The photoinhibition of photosynthesis was mainly induced by white light in shallow water. The inhibitory effects of UV radiation caused a delay in the recovery processes in the afternoon and evening, rather than an inhibitory effect on photosynthesis in the morning. Fucus distichus, growing in the upper intertidal zone, was most insensitive to UV radiation. Algae from the sublittoral zone had problems coping with the natural UV radiation in shallow water, whereas those from the intertidal zone were acclimatized to the unfavourable UV /PAR conditions. By cutting off sequentially the shorter wavelengths of the UV range, the investigated brown algae showed no significantly different effects. In contrast, the red alga Palmaria palmata showed a clear response to the different UV ranges, i.e. the UVB wavelength range was very effective in causing photoinhibition. In addition, the recovery phase was delayed in spite of the low fluence rates impinging on the alga during the course of the day.read more
Citations
More filters
Journal ArticleDOI
The marine ecosystem of Kongsfjorden, Svalbard
Haakon Hop,Tom Pearson,Else Nøst Hegseth,Kit M. Kovacs,Christian Wiencke,Slawek Kwasniewski,Ketil Eiane,Fridtjof Mehlum,Bjørn Gulliksen,Maria Włodarska-Kowalczuk,Christian Lydersen,Jan Marcin Węsławski,Sabine Cochrane,Geir Wing Gabrielsen,Raymond J.G. Leakey,Ole Jørgen Lønne,Marek Zajaczkowski,Stig Falk-Petersen,Mike A. Kendall,Sten-Åke Wängberg,Kai Bischof,Andrey Voronkov,Nikolaj A. Kovaltchouk,Józef Wiktor,Michael Poltermann,Guido di Prisco,Carlo Papucci,S. Gerland +27 more
TL;DR: Kongsfjorden is a glacial fjord in the Arctic (Svalbard) that is influenced by both Atlantic and Arctic water masses and harbours a mixture of boreal and Arctic flora and fauna as discussed by the authors.
Journal ArticleDOI
The genus Laminaria sensu lato : recent insights and developments
Inka Bartsch,Christian Wiencke,Kai Bischof,Cornelia Buchholz,Bela H. Buck,Anja Eggert,Peter Feuerpfeil,Dieter Hanelt,Sabine Jacobsen,Rolf Karez,Ulf Karsten,Markus Molis,Michael Y. Roleda,Hendrik Schubert,Rhena Schumann,Klaus Valentin,Florian Weinberger,Jutta Wiese +17 more
TL;DR: This review about the genus Laminaria sensu lato summarizes the extensive literature that has been published since the overview of the genus given by Kain in 1979, and covers recent insights into phylogeny and taxonomy, and discusses morphotypes, ecotypes, population genetics and demography.
Journal Article
Climate change and Australian marine life
Elvira S. Poloczanska,Russell C. Babcock,Alan J. Butler,Alistair J. Hobday,Ove Hoegh-Guldberg,T. J. Kunz,Richard J. Matear,David A. Milton,Thomas A. Okey,Anthony J. Richardson +9 more
TL;DR: Climate model simulations project oceanic warming, an increase in ocean stratification and decrease in mixing depth, increased ocean acidification, a rise in sea level, alterations in cloud cover and ozone levels altering the levels of solar radiation reaching the ocean surface, and altered storm and rainfall regimes.
Journal ArticleDOI
Algae and UV irradiation: effects on ultrastructure and related metabolic functions.
Andreas Holzinger,Cornelius Lütz +1 more
TL;DR: A broad overview on UV effects on algae is given, with a focus on structurally visible changes and destruction in chloroplasts, mitochondria, and the occurrence of structures that are likely to be related to the UV stress.
Journal ArticleDOI
Ultraviolet radiation shapes seaweed communities
Kai Bischof,Iván Gómez,Markus Molis,Dieter Hanelt,Ulf Karsten,Ulrike H. Lüder,Michael Y. Roleda,Katharina Zacher,Christian Wiencke +8 more
TL;DR: In this paper, the authors present a view on how UVB radiation affects seaweed physiology and ecology and thus shapes the coastal environment by affecting the spatial, species and functional structure of seaweed communities.
References
More filters
Journal ArticleDOI
Chlorophyll Fluorescence and Photosynthesis: The Basics
G. H. Krause,E. Weis +1 more
TL;DR: Fluorescence as a Reaction Competing in the Deactivation of Excited Chlorophyll and the Origin of Fluorescence Emission.
Journal ArticleDOI
Continuous recording of photochemical and non-photochemical chlorophyll fluorescence quenching with a new type of modulation fluorometer.
TL;DR: It is shown that the modulation fluorometer, in combination with the application of saturating light pulses, provides essential information beyond that obtained with conventional chlorophyll fluorometers.
Journal ArticleDOI
Quenching Analysis of Chlorophyll Fluorescence by the Saturation Pulse Method: Particular Aspects Relating to the Study of Eukaryotic Algae and Cyanobacteria
BookDOI
Environmental UV photobiology
TL;DR: In this paper, the authors look at the global depletion of stratospheric ozone and the consequences of predicted increases of solar ultraviolet radiation and the adverse effects of various aspects of human health that are anticipated in response to a change in level of solar UV-B, four dealing specifically with skin cancer.