Synergy of light and nutrients on the photosynthetic efficiency of phytoplankton populations from the Neuse River Estuary, North Carolina

Bergmann, Trisha; Richardson, Tammi L.; Paerl, Hans W.; Pinckney, James L.; Schofield, Oscar

doi:10.1093/plankt/24.9.923

Cited by 48 publications

(35 citation statements)

References 43 publications

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“…Nevertheless, aquatic organisms such as phytoplankton would experience an increase in solar radiation as a feedback mechanism due to climate change: Increased water temperature (due to climate change) would produce a shallower thermocline and thus reduce the depth of the upper mixed layer, thus exposing phytoplankton to higher radiation conditions as well as to higher temperatures. While most investigations dealing with the effects of UVR on phytoplankton photosynthesis have evaluated carbon fixation occurring during the 'dark' reactions (Calvin-Benson cycle: i.e., through radiocarbon incorporation measurements), some others have focused on more specific targets, such as Rubisco (Lesser 1996a;Bouchard et al 2008), xanthophyll pigments (Van De Poll and Buma 2009), carbonic anhydrase activity (Wu and Gao 2009), and the electron transport rate of PSII (Bergmann et al 2002;Villafañ e et al 2007;Bouchard et al 2008). On the other hand, increased temperatures have been known to affect phenology and biodiversity (Wrona et al 2006) as well as plant-herbivore dynamics and food-web length (Beisner et al 1997), among many other effects.…”

Section: Discussionmentioning

confidence: 99%

Increase in Rubisco activity and gene expression due to elevated temperature partially counteracts ultraviolet radiation–induced photoinhibition in the marine diatom Thalassiosira weissflogii

Helbling

Buma

Boelen

et al. 2011

Limnology & Oceanography

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We performed outdoor experiments to evaluate the effect of temperature on photoinhibition properties in the cosmopolitan diatom Thalassiosira weissflogii. Cultures were exposed to solar radiation with or without ultraviolet radiation (UVR, 280-400 nm), UV-A (320-400 nm), and UV-B (280-320 nm) at both 20uC and 25uC. Four possible cellular mechanisms involved in UVR stress were simultaneously addressed: carbon incorporation, chlorophyll a fluorescence of photosystem II, xanthophyll cycle activity, and ribulose-1,5-biphosphate carboxylase : oxygenase (Rubisco) activity and gene expression. Experiments consisted of daily cycles (i.e., the daylight period) and short-term incubations (i.e., 1 h centered on local noon). Samples incubated at 25uC had significantly less UVR-induced inhibition of carbon fixation and effective photochemical quantum yield compared to those incubated at 20uC. At 25uC Rubisco activity and gene expression were significantly higher than at 20uC. The higher Rubisco activity and gene expression were correlated with less dissipation of excess energy, evaluated via non-photochemical quenching, and the de-epoxidation state of the xanthophyll pigments, as more photons could be processed. An increase in temperature due to climate change would partially counteract the negative effects of UVR by increasing the response of metabolic pathways, such as those involved in Rubisco. This, in turn, may have important consequences for the ecosystem, as higher production (due to more Rubisco activity) could be expected under a scenario of global warming.

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Section: Discussionmentioning

confidence: 99%

Increase in Rubisco activity and gene expression due to elevated temperature partially counteracts ultraviolet radiation–induced photoinhibition in the marine diatom Thalassiosira weissflogii

Helbling

Buma

Boelen

et al. 2011

Limnology & Oceanography

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“…Mostajir et al 1999, Wängberg et al 1999, Bergmann et al 2002. Although different from the natural environment, this approach has advantages mostly in terms of the more natural light environment and presence of planktonic communities resembling local conditions.…”

Section: Phytoplankton Dynamics In Mesocosms At the 3 Sitesmentioning

confidence: 99%

“…Several studies have revealed that phytoplankton were more affected by enhanced UV-B radiation under nutrient-limited conditions (Cullen & Lesser 1991, Bergeron & Vincent 1997, Wulff et al 2000, Litchman et al 2002. Nutrient stress may increase the sensitivity to UV-B through the alteration of several mechanisms of protection, defence against UV-B radiation or repair after photodamage (Lesser 1996, Bergmann et al 2002, Litchman et al 2002. In contrast, other studies found little or no increase of UV-B sensitivity in nutrient-stressed phytoplankton (Behrenfeld et al 1994, Furgal & Smith 1997, Veen et al 1997, Wängberg et al 1999.…”

Section: Introductionmentioning

confidence: 99%

Variable phytoplankton response to enhanced UV-B and nitrate addition in mesocosm experiments at three latitudes (Canada, Brazil and Argentina)

Longhi¹,

Ferreyra²,

Schloss³

et al. 2006

Mar. Ecol. Prog. Ser.

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The influence of nitrate enrichment on the response of natural phytoplankton populations to enhanced UV-B radiation was tested during a series of week-long mesocosm (1800 l) experiments carried out in Rimouski (Canada), Ubatuba (Brazil) and Ushuaia (southern Argentina). We set up 2 mesocosms at each site, one was submitted to ambient UV-B levels while the other received enhanced UV-B levels corresponding to a local 60% ozone-depletion scenario, and both were continuously mixed. Samples from the mesocosms were incubated in UV-transparent plastic bags (4 l) floating at the surface for 24 h. Half of these received nitrate, phosphate and silicate enrichments while for the other half nitrate was omitted. Responses in terms of photochemical yield (F v /F m , where F v is variable fluorescence after dark relaxation and F m is maximal fluorescence following short pulses of saturating white light, pulse amplitude-modulated [PAM] fluorescence) and high-performance liquid chromatography (HPLC) pigments, differed among sites and over time, particularly for Rimouski, where a large bloom took place in the mesocosms. Enhanced UV-B significantly increased photoinhibition in the surface bags, while nitrate addition partly relieved this inhibition only during the post-bloom period. The net growth of fucoxanthin was reduced by enhanced UV-B except during the post-bloom period, when it increased, probably because grazing pressure was reduced under enhanced UV-B (strong decrease in ciliates). In Ubatuba, cells were affected by the high ambient-light irradiances at the surface, and enhanced UV-B had no further effect, irrespective of the nutrient status. At Ushuaia, enhanced UV-B prevented all increases of fucoxanthin and chl a, with much less effect on chl b (green algae), and no nutrient response was observed. This strong and consistent negative response to enhanced UV-B is likely to be related to the cold temperature prevailing at Ushuaia at the time of the experiment (slowing repair) as well as the local community composition. In contrast, no effects of enhanced UV-B were observed in the stirred mesocosms at the 3 sites, indicating that mixing moderated the UV-B effects in all 3 experiments.

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“…Several investigations have shown that UVBR inhibits phytoplankton photosynthesis (Vincent & Roy 1993, Bergmann et al 2002, growth and cell division (Karentz et al 1991, Buma et al 1997, Mostajir et al 1999b, nutrient uptake , Mousseau et al 2000, and induces changes in algal specific composition (Neale et al 1994, Mostajir et al 1999a,b, Wängberg et al 2001. Bacterioplankton is also affected by UVBR in several ways, including a reduction in bacterial production (Aas et al 1996, Chatila et al 2001, abundance (Müller-Niklas et al 1995), and viability (Vincent & Roy 1993).…”

Section: Introductionmentioning

confidence: 99%

Non-synergistic effects of water-soluble crude oil and enhanced ultraviolet-B radiation on a natural plankton assemblage

Sargian¹,

Mostajir²,

Chatila³

et al. 2005

Mar. Ecol. Prog. Ser.

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The present study demonstrates the effects of the water-soluble fraction (WSF) of a crude oil, enhanced ultraviolet-B radiation (UVBR: 280 to 320 nm), and the combination of WSF and enhanced UVBR on a natural plankton assemblage (<150 μm) isolated from the lower St. Lawrence Estuary. To study the separate and dual effects of WSF and UVBR, 12 microcosms (9 l) were immersed in the water column of larger mesocosms (polyethylene bags; 1800 l), providing 4 treatments, each in triplicate: (1) NUVBR + WSF (natural UVBR with WSF), (2) HUVBR + WSF (enhanced UVBR with WSF), (3) NUVBR (natural UVBR without WSF), and (4) HUVBR (enhanced UVBR without WSF). During 5 d we monitored the incident radiation, WSF and nutrient concentrations, abundance and production of heterotrophic bacteria and phytoplankton. Strong deleterious effects of WSF and lower effects of UVBR were observed on the phytoplankton assemblage, with a decrease in growth rates accompanied by an increase in mean cell size which reflected a perturbation of the cell division cycle. Using the NUVBR treatement as reference conditions, the above effects resulted in a reduction of 84, 79 and 60% of total abundance of the phytoplankton fraction < 20 μm in the HUVBR + WSF, NUVBR + WSF and HUVBR treatments, respectively. Significant higher values of bacterial abundances were observed in the WSF-added treatments compared to NUVBR without WSF. However, bacterial thymidine incorporation exhibited diel variations, suggesting cumulative UVBR-induced DNA and/or PAHinduced DNA damages, and possible repair mechanisms with the co-occurrence of more available growth substrates from stressed phytoplankton. The absence of significant differences between both WSF-added treatments under the 2 different UVBR conditions suggests that there is no additive interaction between WSF and UVBR. This study provides therefore the first evidence of a non-synergistic interaction between both stresses, and suggests that UVBR-induced effects on marine microorganisms can be completely masked by the strong deleterious effects of soluble petroleum hydrocarbons.KEY WORDS: Ultraviolet radiation · Dissolved hydrocarbons · Non-synergistic effect · Phytoplankton · BacteriaResale or republication not permitted without written consent of the publisher

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Synergy of light and nutrients on the photosynthetic efficiency of phytoplankton populations from the Neuse River Estuary, North Carolina

Cited by 48 publications

References 43 publications

Increase in Rubisco activity and gene expression due to elevated temperature partially counteracts ultraviolet radiation–induced photoinhibition in the marine diatom Thalassiosira weissflogii

Increase in Rubisco activity and gene expression due to elevated temperature partially counteracts ultraviolet radiation–induced photoinhibition in the marine diatom Thalassiosira weissflogii

Variable phytoplankton response to enhanced UV-B and nitrate addition in mesocosm experiments at three latitudes (Canada, Brazil and Argentina)

Non-synergistic effects of water-soluble crude oil and enhanced ultraviolet-B radiation on a natural plankton assemblage

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