Acclimation of brown algal photosynthesis to ultraviolet radiation in Arctic coastal waters (Spitsbergen, Norway)

TY - JOUR

T1 - Acclimation of brown algal photosynthesis to ultraviolet radiation in Arctic coastal waters (Spitsbergen, Norway)

AU - Bischof, K.

AU - Hanelt, D.

AU - Tug, H.

AU - Karsten, U.

AU - Brouwer, P.E.M.

AU - Wiencke, C.

N1 - Reporting year: 1998 Metis note: 2949; CEME; LV; file:///L:/Endnotedatabases/NIOOPUB/pdfs/Pdfs1998/Bischof_ea_2949.pdf

PY - 1998

Y1 - 1998

N2 - In field studies conducted at the Kongsfjord (Spitsbergen) changes of the irradiance in the atmosphere and the sublittoral zone were monitored from the beginning of June until the end of August 1997, to register the minimum and maximum fluxes of ultraviolet and photosynthetically active radiation and to characterise the underwater light climate. Measurements of photosynthesis in three abundant brown algal species (Alaria esculenta, Laminaria saccharina, Saccorhiza dermatodea) were conducted to test whether their photosynthetic performance reflects changing light climate in accordance with depth. Plants sampled at various depths were exposed to controlled fluence rates of photosynthetically active radiation (400-700 nm), W-A (320-400 nm) and UV-B (280-320 nm). Changes in photosynthetic performance during the treatments were monitored by measuring variable chlorophyll fluorescence of photosystem II. In each species, the degree of inhibition of photosynthesis was related to the original collection depth, i.e. shallow- water isolates were more resistant than plants from deeper waters. The results show that macroalgae acclimate effectively to increasing irradiance levels for both photosynthetically active and ultraviolet radiation. However, the kinetics of acclimation are different within the different species. It is shown that one important strategy to cope with higher irradiance levels in shallow waters is the capability for a faster recovery from high light stress compared to isolates from deeper waters. [KEYWORDS: Uv-b radiation; life-history stages; high light stress chlorophyll fluorescence; dictyota-dichotoma; marine macroalgae; photosystem-ii; photoinhibition; field; displacements]

AB - In field studies conducted at the Kongsfjord (Spitsbergen) changes of the irradiance in the atmosphere and the sublittoral zone were monitored from the beginning of June until the end of August 1997, to register the minimum and maximum fluxes of ultraviolet and photosynthetically active radiation and to characterise the underwater light climate. Measurements of photosynthesis in three abundant brown algal species (Alaria esculenta, Laminaria saccharina, Saccorhiza dermatodea) were conducted to test whether their photosynthetic performance reflects changing light climate in accordance with depth. Plants sampled at various depths were exposed to controlled fluence rates of photosynthetically active radiation (400-700 nm), W-A (320-400 nm) and UV-B (280-320 nm). Changes in photosynthetic performance during the treatments were monitored by measuring variable chlorophyll fluorescence of photosystem II. In each species, the degree of inhibition of photosynthesis was related to the original collection depth, i.e. shallow- water isolates were more resistant than plants from deeper waters. The results show that macroalgae acclimate effectively to increasing irradiance levels for both photosynthetically active and ultraviolet radiation. However, the kinetics of acclimation are different within the different species. It is shown that one important strategy to cope with higher irradiance levels in shallow waters is the capability for a faster recovery from high light stress compared to isolates from deeper waters. [KEYWORDS: Uv-b radiation; life-history stages; high light stress chlorophyll fluorescence; dictyota-dichotoma; marine macroalgae; photosystem-ii; photoinhibition; field; displacements]

U2 - 10.1007/s003000050319

DO - 10.1007/s003000050319

M3 - Article

SN - 0722-4060

VL - 20

SP - 388

EP - 395

JO - Polar Biology

JF - Polar Biology

IS - 6

ER -