scholarly journals Fine scale phytoplankton community structure across the Kuroshio Front

2014 ◽  
Vol 36 (4) ◽  
pp. 1017-1030 ◽  
Author(s):  
Sophie Clayton ◽  
Takeyoshi Nagai ◽  
Michael J. Follows
Keyword(s):  
Community Structure ◽  
Phytoplankton Community ◽  
Fine Scale ◽  
Phytoplankton Community Structure ◽  
Kuroshio Front ◽  
The Kuroshio

scholarly journals The impact of fine-scale turbulence on phytoplankton community structure

2014 ◽  
Vol 4 (1) ◽  
pp. 34-49 ◽  
Author(s):  
Andrew D. Barton ◽  
Ben A. Ward ◽  
Richard G. Williams ◽  
Michael J. Follows
Keyword(s):  
Community Structure ◽  
Phytoplankton Community ◽  
Fine Scale ◽  
Phytoplankton Community Structure ◽  
Scale Turbulence ◽  
The Impact

Phytoplankton community structure, as derived from pigment signatures, in the Kuroshio Extension and adjacent regions in winter and spring

2017 ◽  
Vol 73 (4) ◽  
pp. 463-478 ◽  
Author(s):  
Yuta Nishibe ◽  
Kazutaka Takahashi ◽  
Mitsuhide Sato ◽  
Taketoshi Kodama ◽  
Shigeho Kakehi ◽  
...  
Keyword(s):  
Community Structure ◽  
Phytoplankton Community ◽  
Kuroshio Extension ◽  
Phytoplankton Community Structure ◽  
The Kuroshio

scholarly journals Coupling physics and biogeochemistry thanks to high-resolution observations of the phytoplankton community structure in the northwestern Mediterranean Sea

2018 ◽  
Vol 15 (5) ◽  
pp. 1579-1606 ◽  
Author(s):  
Pierre Marrec ◽  
Gérald Grégori ◽  
Andrea M. Doglioli ◽  
Mathilde Dugenne ◽  
Alice Della Penna ◽  
...  
Keyword(s):  
Community Structure ◽  
High Resolution ◽  
Surface Waters ◽  
Phytoplankton Community ◽  
Fine Scale ◽  
Phytoplankton Community Structure ◽  
Red Fluorescence ◽  
Cold Core ◽  
Northwestern Mediterranean

Abstract. Fine-scale physical structures and ocean dynamics strongly influence and regulate biogeochemical and ecological processes. These processes are particularly challenging to describe and understand because of their ephemeral nature. The OSCAHR (Observing Submesoscale Coupling At High Resolution) campaign was conducted in fall 2015 in which a fine-scale structure (1–10 km∕1–10 days) in the northwestern Mediterranean Ligurian subbasin was pre-identified using both satellite and numerical modeling data. Along the ship track, various variables were measured at the surface (temperature, salinity, chlorophyll a and nutrient concentrations) with ADCP current velocity. We also deployed a new model of the CytoSense automated flow cytometer (AFCM) optimized for small and dim cells, for near real-time characterization of the surface phytoplankton community structure of surface waters with a spatial resolution of a few kilometers and an hourly temporal resolution. For the first time with this optimized version of the AFCM, we were able to fully resolve Prochlorococcus picocyanobacteria in addition to the easily distinguishable Synechococcus. The vertical physical dynamics and biogeochemical properties of the studied area were investigated by continuous high-resolution CTD profiles thanks to a moving vessel profiler (MVP) during the vessel underway associated with a high-resolution pumping system deployed during fixed stations allowing sampling of the water column at a fine resolution (below 1 m). The observed fine-scale feature presented a cyclonic structure with a relatively cold core surrounded by warmer waters. Surface waters were totally depleted in nitrate and phosphate. In addition to the doming of the isopycnals by the cyclonic circulation, an intense wind event induced Ekman pumping. The upwelled subsurface cold nutrient-rich water fertilized surface waters and was marked by an increase in Chl a concentration. Prochlorococcus and pico- and nano-eukaryotes were more abundant in cold core waters, while Synechococcus dominated in warm boundary waters. Nanoeukaryotes were the main contributors (>50 %) in terms of pigment content (red fluorescence) and biomass. Biological observations based on the mean cell's red fluorescence recorded by AFCM combined with physical properties of surface waters suggest a distinct origin for two warm boundary waters. Finally, the application of a matrix growth population model based on high-frequency AFCM measurements in warm boundary surface waters provides estimates of in situ growth rate and apparent net primary production for Prochlorococcus (μ=0.21 d−1, NPP =0.11 mgCm-3d-1) and Synechococcus (μ=0.72 d−1, NPP =2.68 mgCm-3d-1), which corroborate their opposite surface distribution pattern. The innovative adaptive strategy applied during OSCAHR with a combination of several multidisciplinary and complementary approaches involving high-resolution in situ observations and sampling, remote-sensing and model simulations provided a deeper understanding of the marine biogeochemical dynamics through the first trophic levels.

Seasonal changes in phytoplankton community structure in a bioluminescent lagoon, St. Croix, US Virgin Islands

2018 ◽  
Vol 81 (2) ◽  
pp. 109-124 ◽  
Author(s):  
JL Pinckney ◽  
C Tomas ◽  
DI Greenfield ◽  
K Reale-Munroe ◽  
B Castillo ◽  
...  
Keyword(s):  
Community Structure ◽  
Seasonal Changes ◽  
Phytoplankton Community ◽  
Virgin Islands ◽  
Phytoplankton Community Structure ◽  
Us Virgin Islands

scholarly journals Response of ocean phytoplankton community structure to climate change over the 21st century: partitioning the effects of nutrients, temperature and light

2010 ◽  
Vol 7 (12) ◽  
pp. 3941-3959 ◽  
Author(s):  
I. Marinov ◽  
S. C. Doney ◽  
I. D. Lima
Keyword(s):  
Climate Change ◽  
Community Structure ◽  
Sea Ice ◽  
Phytoplankton Biomass ◽  
Phytoplankton Community ◽  
Vertical Mixing ◽  
Phytoplankton Community Structure ◽  
Marginal Sea ◽  
Small Phytoplankton ◽  
The Impact

Abstract. The response of ocean phytoplankton community structure to climate change depends, among other factors, upon species competition for nutrients and light, as well as the increase in surface ocean temperature. We propose an analytical framework linking changes in nutrients, temperature and light with changes in phytoplankton growth rates, and we assess our theoretical considerations against model projections (1980–2100) from a global Earth System model. Our proposed "critical nutrient hypothesis" stipulates the existence of a critical nutrient threshold below (above) which a nutrient change will affect small phytoplankton biomass more (less) than diatom biomass, i.e. the phytoplankton with lower half-saturation coefficient K are influenced more strongly in low nutrient environments. This nutrient threshold broadly corresponds to 45° S and 45° N, poleward of which high vertical mixing and inefficient biology maintain higher surface nutrient concentrations and equatorward of which reduced vertical mixing and more efficient biology maintain lower surface nutrients. In the 45° S–45° N low nutrient region, decreases in limiting nutrients – associated with increased stratification under climate change – are predicted analytically to decrease more strongly the specific growth of small phytoplankton than the growth of diatoms. In high latitudes, the impact of nutrient decrease on phytoplankton biomass is more significant for diatoms than small phytoplankton, and contributes to diatom declines in the northern marginal sea ice and subpolar biomes. In the context of our model, climate driven increases in surface temperature and changes in light are predicted to have a stronger impact on small phytoplankton than on diatom biomass in all ocean domains. Our analytical predictions explain reasonably well the shifts in community structure under a modeled climate-warming scenario. Climate driven changes in nutrients, temperature and light have regionally varying and sometimes counterbalancing impacts on phytoplankton biomass and structure, with nutrients and temperature dominant in the 45° S–45° N band and light-temperature effects dominant in the marginal sea-ice and subpolar regions. As predicted, decreases in nutrients inside the 45° S–45° N "critical nutrient" band result in diatom biomass decreasing more than small phytoplankton biomass. Further stratification from global warming could result in geographical shifts in the "critical nutrient" threshold and additional changes in ecology.

Sign in / Sign up

Export Citation Format

Share Document