Limits...
The Temporal Dynamics of Coastal Phytoplankton and Bacterioplankton in the Eastern Mediterranean Sea.

Raveh O, David N, Rilov G, Rahav E - PLoS ONE (2015)

Bottom Line: Based on size fractionating, picophytoplankton was abundant during the summer, whereas nano-microphytoplankton predominated during the winter and early spring, which were also evident in the size-fractionated primary production rates.Autotrophic abundance and production correlated negatively with temperature, but did not correlate with inorganic nutrients.These findings have important ecological implications for food web dynamics and for biological carbon sequestration in this understudied region.

View Article: PubMed Central - PubMed

Affiliation: National Institute of Oceanography, Israel Oceanographic and Limnological Research, Haifa, Israel.

ABSTRACT
This study considers variability in phytoplankton and heterotrophic bacterial abundances and production rates, in one of the most oligotrophic marine regions in the world-the Levantine Basin. The temporal dynamics of these planktonic groups were studied in the coastal waters of the southeastern Mediterranean Sea approximately every two weeks for a total of two years. Heterotrophic bacteria were abundant mostly during late summer and midwinter, and were positively correlated with bacterial production and with N2 fixation. Based on size fractionating, picophytoplankton was abundant during the summer, whereas nano-microphytoplankton predominated during the winter and early spring, which were also evident in the size-fractionated primary production rates. Autotrophic abundance and production correlated negatively with temperature, but did not correlate with inorganic nutrients. Furthermore, a comparison of our results with results from the open Levantine Basin demonstrates that autotrophic and heterotrophic production, as well as N2 fixation rates, are considerably higher in the coastal habitat than in the open sea, while nutrient levels or cell abundance are not different. These findings have important ecological implications for food web dynamics and for biological carbon sequestration in this understudied region.

No MeSH data available.


The temporal dynamics of autotrophic bacterioplankton in the coastal eastern Mediterranean Sea.Data presented are for Chl a (A) pico-phytoplankton (B) and primary production, PP (C) between April 2013 and April 2015.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4608699&req=5

pone.0140690.g002: The temporal dynamics of autotrophic bacterioplankton in the coastal eastern Mediterranean Sea.Data presented are for Chl a (A) pico-phytoplankton (B) and primary production, PP (C) between April 2013 and April 2015.

Mentions: The total chlorophyll a (Chl a) levels (filtered onto 0.7 μm GF/F) showed clear seasonal dynamics, with the lowest concentrations measured during summer (~0.10 μg L-1) and the peak concentrations measured during wintertime (~0.55 μg L-1) (Fig 2A). The nano-microphytoplankton Chl a (filtered onto a 3 μm filter) concentrations displayed similar seasonal patterns, ranging from 0.01 μg L-1 in July and August of 2013 to 0.45 μg L-1 in January 2014 (Fig 2A). The relative contribution of nano-microphytoplankton Chl a was high during both winters (~60%) and significantly lower during both summers, usually below 30% (Table 2). The abundance of cyanobacteria (i.e., Synechococcus and Prochlorococcus) and picoeukaryotes derived from flow-cytometric analyses was overall throughout both 2014 and 2015 (Fig 2B, S1 Table), and followed the same pattern as Chl a (Fig 2A). Concurrent with the abundances, the contribution of picophytoplankton Chl a was highest during the summer (57–91%) and the lowest during winter (<50%, Table 2).


The Temporal Dynamics of Coastal Phytoplankton and Bacterioplankton in the Eastern Mediterranean Sea.

Raveh O, David N, Rilov G, Rahav E - PLoS ONE (2015)

The temporal dynamics of autotrophic bacterioplankton in the coastal eastern Mediterranean Sea.Data presented are for Chl a (A) pico-phytoplankton (B) and primary production, PP (C) between April 2013 and April 2015.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4608699&req=5

pone.0140690.g002: The temporal dynamics of autotrophic bacterioplankton in the coastal eastern Mediterranean Sea.Data presented are for Chl a (A) pico-phytoplankton (B) and primary production, PP (C) between April 2013 and April 2015.
Mentions: The total chlorophyll a (Chl a) levels (filtered onto 0.7 μm GF/F) showed clear seasonal dynamics, with the lowest concentrations measured during summer (~0.10 μg L-1) and the peak concentrations measured during wintertime (~0.55 μg L-1) (Fig 2A). The nano-microphytoplankton Chl a (filtered onto a 3 μm filter) concentrations displayed similar seasonal patterns, ranging from 0.01 μg L-1 in July and August of 2013 to 0.45 μg L-1 in January 2014 (Fig 2A). The relative contribution of nano-microphytoplankton Chl a was high during both winters (~60%) and significantly lower during both summers, usually below 30% (Table 2). The abundance of cyanobacteria (i.e., Synechococcus and Prochlorococcus) and picoeukaryotes derived from flow-cytometric analyses was overall throughout both 2014 and 2015 (Fig 2B, S1 Table), and followed the same pattern as Chl a (Fig 2A). Concurrent with the abundances, the contribution of picophytoplankton Chl a was highest during the summer (57–91%) and the lowest during winter (<50%, Table 2).

Bottom Line: Based on size fractionating, picophytoplankton was abundant during the summer, whereas nano-microphytoplankton predominated during the winter and early spring, which were also evident in the size-fractionated primary production rates.Autotrophic abundance and production correlated negatively with temperature, but did not correlate with inorganic nutrients.These findings have important ecological implications for food web dynamics and for biological carbon sequestration in this understudied region.

View Article: PubMed Central - PubMed

Affiliation: National Institute of Oceanography, Israel Oceanographic and Limnological Research, Haifa, Israel.

ABSTRACT
This study considers variability in phytoplankton and heterotrophic bacterial abundances and production rates, in one of the most oligotrophic marine regions in the world-the Levantine Basin. The temporal dynamics of these planktonic groups were studied in the coastal waters of the southeastern Mediterranean Sea approximately every two weeks for a total of two years. Heterotrophic bacteria were abundant mostly during late summer and midwinter, and were positively correlated with bacterial production and with N2 fixation. Based on size fractionating, picophytoplankton was abundant during the summer, whereas nano-microphytoplankton predominated during the winter and early spring, which were also evident in the size-fractionated primary production rates. Autotrophic abundance and production correlated negatively with temperature, but did not correlate with inorganic nutrients. Furthermore, a comparison of our results with results from the open Levantine Basin demonstrates that autotrophic and heterotrophic production, as well as N2 fixation rates, are considerably higher in the coastal habitat than in the open sea, while nutrient levels or cell abundance are not different. These findings have important ecological implications for food web dynamics and for biological carbon sequestration in this understudied region.

No MeSH data available.