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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 relationship between temperature and bacterioplankton in the coastal eastern Mediterranean Sea.Data presented are for total Chl a (A), primary production (B), bacterial abundance (C), bacterial production (D) and N2 fixations (E) during the April 2013 to April 2015 sampling period.
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pone.0140690.g005: The relationship between temperature and bacterioplankton in the coastal eastern Mediterranean Sea.Data presented are for total Chl a (A), primary production (B), bacterial abundance (C), bacterial production (D) and N2 fixations (E) during the April 2013 to April 2015 sampling period.

Mentions: The temporal distributions of Chl a and primary production correlated negatively (Pearson correlation, p< 0.001 and p< 0.0001 respectively) with temperature, and thus the largest algal biomass and the highest algal production were recorded during winter when the water temperature were the coldest (Fig 5A and 5B). In contrast, bacterial abundance, bacterial production and N2 fixation exhibited a different temporal pattern, with minimal abundances/rates during spring and autumn, when the surface water temperature was ~22°C, and maximal values during winter and summer (Fig 5C, 5D and 5E).


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 relationship between temperature and bacterioplankton in the coastal eastern Mediterranean Sea.Data presented are for total Chl a (A), primary production (B), bacterial abundance (C), bacterial production (D) and N2 fixations (E) during the April 2013 to April 2015 sampling period.
© Copyright Policy
Related In: Results  -  Collection

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

pone.0140690.g005: The relationship between temperature and bacterioplankton in the coastal eastern Mediterranean Sea.Data presented are for total Chl a (A), primary production (B), bacterial abundance (C), bacterial production (D) and N2 fixations (E) during the April 2013 to April 2015 sampling period.
Mentions: The temporal distributions of Chl a and primary production correlated negatively (Pearson correlation, p< 0.001 and p< 0.0001 respectively) with temperature, and thus the largest algal biomass and the highest algal production were recorded during winter when the water temperature were the coldest (Fig 5A and 5B). In contrast, bacterial abundance, bacterial production and N2 fixation exhibited a different temporal pattern, with minimal abundances/rates during spring and autumn, when the surface water temperature was ~22°C, and maximal values during winter and summer (Fig 5C, 5D and 5E).

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.