Solar PAR and UVR modify the community composition and photosynthetic activity of sea ice algae

Enberg, Sara; Piiparinen, Jonna; Majaneva, Markus; Vähätalo, Anssi V.; Autio, Riitta; Rintala, Janne-Markus

doi:10.1093/femsec/fiv102

Cited by 13 publications

(9 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our observations are consistent with previous reports that species of Heterocapsa are less resistant to light fluctuations than other taxa (Laurion and Roy , Lewandowska and Sommer , Enberg et al. ), and support the idea that photoacclimation potential is variable across microalgal species (Johnsen and Sakshaug ). Strain variability is also important to consider when characterizing the photophysiology of a microalgal species since strains can evolve photoadaptive traits specific to their environment, leading to significant photo‐response variability (Falkowski and Chen , David et al.…”

Section: Discussionsupporting

confidence: 93%

Contrasting effects of high‐intensity photosynthetically active radiation on two bloom‐forming dinoflagellates

Cooney

Fredrickson

Bright

et al. 2019

Journal of Phycology

View full text Add to dashboard Cite

While light limitation can inhibit bloom formation in dinoflagellates, the potential for high‐intensity photosynthetically active radiation (PAR) to inhibit blooms by causing stress or damage has not been well‐studied. We measured the effects of high‐intensity PAR on the bloom‐forming dinoflagellates Alexandrium fundyense and Heterocapsa rotundata. Various physiological parameters (photosynthetic efficiency Fv/Fm, cell permeability, dimethylsulfoniopropionate [DMSP], cell volume, and chlorophyll‐a content) were measured before and after exposure to high‐intensity natural sunlight in short‐term light stress experiments. In addition, photosynthesis‐irradiance (P‐E) responses were compared for cells grown at different light levels to assess the capacity for photophysiological acclimation in each species. Experiments revealed distinct species‐specific responses to high PAR. While high light decreased Fv/Fm in both species, A. fundyense showed little additional evidence of light stress in short‐term experiments, although increased membrane permeability and intracellular DMSP indicated a response to handling. P‐E responses further indicated a high light‐adapted species with Chl‐a inversely proportional to growth irradiance and no evidence of photoinhibition; reduced maximum per‐cell photosynthesis rates suggest a trade‐off between photoprotection and C fixation in high light‐acclimated cells. Heterocapsa rotundata cells, in contrast, swelled in response to high light and sometimes lysed in short‐term experiments, releasing DMSP. P‐E responses confirmed a low light‐adapted species with high photosynthetic efficiencies associated with trade‐offs in the form of substantial photoinhibition and a lack of plasticity in Chl‐a content. These contrasting responses illustrate that high light constrains dinoflagellate community composition through species‐specific stress effects, with consequences for bloom formation and ecological interactions within the plankton.

show abstract

Section: Discussionsupporting

confidence: 93%

Contrasting effects of high‐intensity photosynthetically active radiation on two bloom‐forming dinoflagellates

Cooney

Fredrickson

Bright

et al. 2019

Journal of Phycology

View full text Add to dashboard Cite

show abstract

“…It should be noted that irradiance levels in our young ice case (on average 114 and range 30-350 µmol photons m −2 s −1 ) were relatively high throughout the study period (Kauko et al, 2017). Light has been observed to impact community composition when experimentally perturbed (Enberg et al, 2015) or under different snow cover (Rózanska et al, 2009;Alou-Font et al, 2013). Alou-Font et al (2013) observed no dinoflagellates under thick snow cover (lower light), but in our case they were found in both ice types.…”

Section: Irradiancementioning

confidence: 41%

Algal Colonization of Young Arctic Sea Ice in Spring

et al. 2018

View full text Add to dashboard Cite

The importance of newly formed sea ice in spring is likely to increase with formation of leads in a more dynamic Arctic icescape. We followed the ice algal species succession in young ice (≤0.27 m) in spring at high temporal resolution (sampling every second day for 1 month in May-June 2015) in the Arctic Ocean north of Svalbard. We document the early development of the ice algal community based on species abundance and chemotaxonomic marker pigments, and relate the young-ice algal community to the communities in the under-ice water column and the surrounding older ice. The seeding source seemed to vary between algal groups. Dinoflagellates were concluded to originate from the water column and diatoms from the surrounding older ice, which emphasizes the importance of older ice as a seeding source over deep oceanic regions and in early spring when algal abundance in the water column is low. In total, 120 taxa (80 identified to species or genus level) were recorded in the young ice. The protist community developed over the study period from a ciliate, flagellate, and dinoflagellate dominated community to one dominated by pennate diatoms. Environmental variables such as light were not a strong driver for the community composition, based on statistical analysis and comparison to the surrounding thicker ice with low light transmission. The photoprotective carotenoids to Chl a ratio increased over time to levels found in other highlight habitats, which shows that the algae were able to acclimate to the light levels of the thin ice. The development into a pennate diatom-dominated community, similar to the older ice, suggests that successional patterns tend toward ice-associated algae fairly independent of environmental conditions like light availability, season or ice type, and that biological traits, including morphological and physiological specialization to the sea ice habitat, play an important role in colonization of the sea ice environment. However, recruitment of ice-associated algae could be negatively affected by the ongoing loss of older ice, which acts as a seeding repository.

show abstract

“…A possible explanation for the high Chl a concentrations in the darker treatments could be that the photoautotrophs produced more chlorophyll to compensate for the decreased light availability (Richardson et al ). Phytoplankton increase their Chl a to biomass ratio when light availability decreases (Enberg et al ). Accordingly, we found the highest Chl a per phytoplankton individual and highest Chl a per phytoplankton biovolume in the DOC‐shading treatment (Supporting Information Fig.…”

Section: Discussionmentioning

confidence: 99%

Colored organic matter increases CO₂ in meso‐eutrophic lake water through altered light climate and acidity

Nydahl

Wallin

Tranvik

et al. 2018

Limnology & Oceanography

View full text Add to dashboard Cite

Many surface waters across the boreal region are browning due to increased concentrations of colored allochthonous dissolved organic carbon (DOC). Browning may stimulate heterotrophic metabolism, may have a shading effect constraining primary production, and may acidify the water leading to decreased pH with a subsequent shift in the carbonate system. All these effects are expected to result in increased lake water carbon dioxide (CO2) concentrations. We tested here these expectations by assessing the effects of both altered allochthonous DOC input and light conditions through shading on lake water CO2 concentrations. We used two mesocosm experiments with water from the meso‐eutrophic Lake Erken, Sweden, to determine the relative importance of bacterial activities, primary production, and shifts in the carbonate system on CO2 concentrations. We found that DOC addition and shading resulted in a significant increase in partial pressure of CO2 (pCO2) in all mesocosms. Surprisingly, there was no relationship between bacterial activities and pCO2. Instead the experimental reduction of light by DOC and/or shading decreased the photosynthesis to respiration ratio leading to increased pCO2. Another driving force behind the observed pCO2 increase was a significant decrease in pH, caused by a decline in photosynthesis and the input of acidic DOC. Considering that colored allochthonous DOC may increase in a warmer and wetter climate, our results could also apply for whole lake ecosystems and pCO2 may increase in many lakes through a reduction in the rate of photosynthesis and decreased pH.

show abstract

Solar PAR and UVR modify the community composition and photosynthetic activity of sea ice algae

Cited by 13 publications

References 59 publications

Contrasting effects of high‐intensity photosynthetically active radiation on two bloom‐forming dinoflagellates

Contrasting effects of high‐intensity photosynthetically active radiation on two bloom‐forming dinoflagellates

Algal Colonization of Young Arctic Sea Ice in Spring

Colored organic matter increases CO₂ in meso‐eutrophic lake water through altered light climate and acidity

Contact Info

Product

Resources

About

Solar PAR and UVR modify the community composition and photosynthetic activity of sea ice algae

Cited by 13 publications

References 59 publications

Contrasting effects of high‐intensity photosynthetically active radiation on two bloom‐forming dinoflagellates

Contrasting effects of high‐intensity photosynthetically active radiation on two bloom‐forming dinoflagellates

Algal Colonization of Young Arctic Sea Ice in Spring

Colored organic matter increases CO2 in meso‐eutrophic lake water through altered light climate and acidity

Contact Info

Product

Resources

About

Colored organic matter increases CO₂ in meso‐eutrophic lake water through altered light climate and acidity