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Long-term changes in cyanobacteria populations in lake kinneret (sea of galilee), Israel: an eco-physiological outlook.

Hadas O, Kaplan A, Sukenik A - Life (Basel) (2015)

Bottom Line: Concomitantly, bloom events of Microcystis sp. (Chroococcales) during winter-spring intensified.The gradual decrease in the concentration of total and dissolved phosphorus and total and dissolved nitrogen and an increase in alkalinity, pH and salinity, combined with the physiological features of cyanobacteria, probably contributed to the success of cyanobacteria.The data presented here indicate that the trend of the continuous decline of nutrients may not be sufficient to reduce and to control the abundance and proliferation of toxic and non-toxic cyanobacteria.

View Article: PubMed Central - PubMed

Affiliation: The Yigal Allon Kinneret Limnological Laboratory, Israel Oceanographic and Limnological Research, Migdal, Israel. orah@ocean.org.il.

ABSTRACT
The long-term record of cyanobacteria abundance in Lake Kinneret (Sea of Galilee), Israel, demonstrates changes in cyanobacteria abundance and composition in the last five decades. New invasive species of the order Nostocales (Aphanizomenon ovalisporum and Cylindrospermopsis raciborskii) became part of the annual phytoplankton assemblage during summer-autumn. Concomitantly, bloom events of Microcystis sp. (Chroococcales) during winter-spring intensified. These changes in cyanobacteria pattern may be partly attributed to the management policy in Lake Kinneret's vicinity and watershed aimed to reduce effluent discharge to the lake and partly to climate changes in the region; i.e., increased water column temperature, less wind and reduced precipitation. The gradual decrease in the concentration of total and dissolved phosphorus and total and dissolved nitrogen and an increase in alkalinity, pH and salinity, combined with the physiological features of cyanobacteria, probably contributed to the success of cyanobacteria. The data presented here indicate that the trend of the continuous decline of nutrients may not be sufficient to reduce and to control the abundance and proliferation of toxic and non-toxic cyanobacteria.

No MeSH data available.


Related in: MedlinePlus

The yearly average of various limnological parameters in the upper water column of Lake Kinneret for 1974–2013: (a) total nitrogen (TN) and total dissolved nitrogen (TDN); (b) total phosphorus (TP) and total dissolved phosphorus (TDP); and (c) alkalinity.
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life-05-00418-f002: The yearly average of various limnological parameters in the upper water column of Lake Kinneret for 1974–2013: (a) total nitrogen (TN) and total dissolved nitrogen (TDN); (b) total phosphorus (TP) and total dissolved phosphorus (TDP); and (c) alkalinity.

Mentions: The multiannual data of the yearly average of TN and TDN concentrations (Figure 2) reflect the changes in the management policy in the lake vicinity. The data can be divided into two periods: 1974–1990 and 1990–2013. The first period is characterized by a gradual decrease in TDN from 0.9 mg N L−1 measured in 1974 to 0.3 mg N L−1 measured in 1990. The second period since the 1990s began with the exceptionally rainy year of 1992 (beginning in December 1991), with an occasional increase in TP and TDN due to the water runoff entering the lake via the Jordan River. The sharp decrease in TDN, 0.39 mg N L−1 in 1994, continues the trend of lower TDN concentrations, with some fluctuations during exceptionally rainy years (i.e., 2002–2003). A statistical analysis of the DIN (NH4+, NO3−) concentrations on an annual and seasonal basis showed a significant difference between these two periods, mostly apparent during the summer months. Much lower DIN concentrations were reported in the last two decades compared to the previous period [22]. Taking into account that concentrations of dissolved nutrients are strongly influenced by the uptake of phytoplankton, the total nitrogen (TN) concentrations depicted in Figure 2 indicate a generally multiannual trend that follows TDN. The total nitrogen ranged between 1.21 to 0.38 mg N L−1 in the time period from1974 to 2014 (Figure 2). The average for the years 1974–1980 was 0.9 mg N L−1, and since 1981, a decrease in TN was recorded with an average of 0.5 mg N L−1 during 2001–2014.


Long-term changes in cyanobacteria populations in lake kinneret (sea of galilee), Israel: an eco-physiological outlook.

Hadas O, Kaplan A, Sukenik A - Life (Basel) (2015)

The yearly average of various limnological parameters in the upper water column of Lake Kinneret for 1974–2013: (a) total nitrogen (TN) and total dissolved nitrogen (TDN); (b) total phosphorus (TP) and total dissolved phosphorus (TDP); and (c) alkalinity.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4390860&req=5

life-05-00418-f002: The yearly average of various limnological parameters in the upper water column of Lake Kinneret for 1974–2013: (a) total nitrogen (TN) and total dissolved nitrogen (TDN); (b) total phosphorus (TP) and total dissolved phosphorus (TDP); and (c) alkalinity.
Mentions: The multiannual data of the yearly average of TN and TDN concentrations (Figure 2) reflect the changes in the management policy in the lake vicinity. The data can be divided into two periods: 1974–1990 and 1990–2013. The first period is characterized by a gradual decrease in TDN from 0.9 mg N L−1 measured in 1974 to 0.3 mg N L−1 measured in 1990. The second period since the 1990s began with the exceptionally rainy year of 1992 (beginning in December 1991), with an occasional increase in TP and TDN due to the water runoff entering the lake via the Jordan River. The sharp decrease in TDN, 0.39 mg N L−1 in 1994, continues the trend of lower TDN concentrations, with some fluctuations during exceptionally rainy years (i.e., 2002–2003). A statistical analysis of the DIN (NH4+, NO3−) concentrations on an annual and seasonal basis showed a significant difference between these two periods, mostly apparent during the summer months. Much lower DIN concentrations were reported in the last two decades compared to the previous period [22]. Taking into account that concentrations of dissolved nutrients are strongly influenced by the uptake of phytoplankton, the total nitrogen (TN) concentrations depicted in Figure 2 indicate a generally multiannual trend that follows TDN. The total nitrogen ranged between 1.21 to 0.38 mg N L−1 in the time period from1974 to 2014 (Figure 2). The average for the years 1974–1980 was 0.9 mg N L−1, and since 1981, a decrease in TN was recorded with an average of 0.5 mg N L−1 during 2001–2014.

Bottom Line: Concomitantly, bloom events of Microcystis sp. (Chroococcales) during winter-spring intensified.The gradual decrease in the concentration of total and dissolved phosphorus and total and dissolved nitrogen and an increase in alkalinity, pH and salinity, combined with the physiological features of cyanobacteria, probably contributed to the success of cyanobacteria.The data presented here indicate that the trend of the continuous decline of nutrients may not be sufficient to reduce and to control the abundance and proliferation of toxic and non-toxic cyanobacteria.

View Article: PubMed Central - PubMed

Affiliation: The Yigal Allon Kinneret Limnological Laboratory, Israel Oceanographic and Limnological Research, Migdal, Israel. orah@ocean.org.il.

ABSTRACT
The long-term record of cyanobacteria abundance in Lake Kinneret (Sea of Galilee), Israel, demonstrates changes in cyanobacteria abundance and composition in the last five decades. New invasive species of the order Nostocales (Aphanizomenon ovalisporum and Cylindrospermopsis raciborskii) became part of the annual phytoplankton assemblage during summer-autumn. Concomitantly, bloom events of Microcystis sp. (Chroococcales) during winter-spring intensified. These changes in cyanobacteria pattern may be partly attributed to the management policy in Lake Kinneret's vicinity and watershed aimed to reduce effluent discharge to the lake and partly to climate changes in the region; i.e., increased water column temperature, less wind and reduced precipitation. The gradual decrease in the concentration of total and dissolved phosphorus and total and dissolved nitrogen and an increase in alkalinity, pH and salinity, combined with the physiological features of cyanobacteria, probably contributed to the success of cyanobacteria. The data presented here indicate that the trend of the continuous decline of nutrients may not be sufficient to reduce and to control the abundance and proliferation of toxic and non-toxic cyanobacteria.

No MeSH data available.


Related in: MedlinePlus