Ultraviolet-B radiation effects on inorganic nitrogen uptake by natural assemblages of oceanic plankton

Journal Article · Wed Feb 01 04:00:00 EST 1995 · Journal of Phycology

DOI:https://doi.org/10.1111/j.0022-3646.1995.00025.x· OSTI ID:61856

Behrenfeld, M J ^[1]; Lean, D R.S. ^[2]; Lee, H II ^[3]

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1. Brookhaven National Lab., Upton, NY (United States)
2. National Water Research Institute, Ontario (Canada)
3. EPA Environmental Research Lab., Newport, OR (United States)

Ultraviolet-B radiation (UVBR: 290-320 nm) inhibited ammonium uptake ({rho}{sub NH4}) and nitrate uptake ({rho}{sub NO3}) in natural plankton assemblages collected during a transect from 37{degrees}N to 55{degrees}N in the Pacific Ocean. Comparison of responses in {rho}{sub NH4} to ambient solar- and lamp-enhanced UVBR spectra allowed calculation of an action spectrum for {rho}{sub NH4} inhibition. The slope of the action spectrum for {rho}{sub NH4} is half as steep as action spectra for UVBR inhibition of photosynthetic carbon uptake. Consequently, UVBR-induced photoinhibition of {rho}{sub NH4} extends to greater depths than inhibition of carbon fixation due to the greater relative effect of longer UVBR wavelengths. Inhibition of {rho}{sub NH4} was dependent upon UVBR dose when doses were weighted by the {rho}{sub NH4} action spectrum. Dependence of UVBR inhibition of {rho}{sub NH4} on dose rate was not apparent. We found that near-surface {rho}{sub NH4} and {rho}{sub NO3} can be overestimated in excess of 50% when measured using standard incubation vessels made of UVBR-absorbing materials such as polycarbonate. 68 refs., 9 figs., 1 tab.

• Sponsoring Organization: USDOE
• OSTI ID: 61856
• Journal Information: Journal of Phycology, Journal Name: Journal of Phycology Journal Issue: 1 Vol. 31; ISSN 0022-3646; ISSN JPYLAJ
• Country of Publication: United States
• Language: English

Related Subjects

56 BIOLOGY AND MEDICINE
APPLIED STUDIES
AQUATIC ORGANISMS
BIOLOGICAL RADIATION EFFECTS
NITROGEN
PLANKTON
SEAS
ULTRAVIOLET RADIATION
UPTAKE