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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 annual maximum biomass of (a) Nostocales species, (b) Chroococcales species and (c) Peridinium and total biomass in Lake Kinneret, 1969–2014. The biomass measurements were based on phytoplankton counts in samples collected from various depths at biweekly intervals. Depth-integrated biomass was done as described by Berman and Pollingher (1974) [17] and Zohary (2004) [18]. During stratification, the depth-integrated biomass was calculated from zero to mid-thermocline, between 15 and 20 m (epilimnion); during mixis, the integration was over the entire water column. Wet weight (WW) was calculated according to the geometric shape of the species [19], assuming that the density of the algae is one.
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life-05-00418-f001: The annual maximum biomass of (a) Nostocales species, (b) Chroococcales species and (c) Peridinium and total biomass in Lake Kinneret, 1969–2014. The biomass measurements were based on phytoplankton counts in samples collected from various depths at biweekly intervals. Depth-integrated biomass was done as described by Berman and Pollingher (1974) [17] and Zohary (2004) [18]. During stratification, the depth-integrated biomass was calculated from zero to mid-thermocline, between 15 and 20 m (epilimnion); during mixis, the integration was over the entire water column. Wet weight (WW) was calculated according to the geometric shape of the species [19], assuming that the density of the algae is one.

Mentions: The long-term record of cyanobacteria in Lake Kinneret comprises 41 species and genera from three main orders; Nostocales, Chroococcales and Oscillatoriales. Members of the latter order were sporadically observed [20]. Variations in the relative species composition and domination on multiannual scales (Figure 1) demonstrate that the annual total cyanobacteria biomass can be divided into three periods: (1) from 1969 to the mid-1980s; (2) from the mid-1980s to the mid-1990s; and (3) from 1994 to present. During the first period, cyanobacteria comprised a small fraction of the total phytoplankton biomass (the annual average from 1969–1985 ranged between <0.1% and 0.9% of the total biomass), and Chroococcales species dominated the cyanobacterial assemblage. From the mid-1980s to the mid-1990s, the cyanobacteria population was substantially suppressed. During that period, the dominating taxa were P. gatunense during winter-spring. Aulacoseira granulata, which reached a biomass of 182 g m−2 in 1988, and chlorophytes (Pediastrum sp., Coelastrum sp., Scenedesmus sp. and Tetraedron). Since 1994, blooms of Microcystis (Chroococcales) and blooms of Aphanizomenon ovalisporum and Cylindrospermopsis raciborskii (Nostocales) intensified [11,18,21,22]. Here, we bring a short description of the common and most abundant cyanobacteria species observed in Lake Kinneret.


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 annual maximum biomass of (a) Nostocales species, (b) Chroococcales species and (c) Peridinium and total biomass in Lake Kinneret, 1969–2014. The biomass measurements were based on phytoplankton counts in samples collected from various depths at biweekly intervals. Depth-integrated biomass was done as described by Berman and Pollingher (1974) [17] and Zohary (2004) [18]. During stratification, the depth-integrated biomass was calculated from zero to mid-thermocline, between 15 and 20 m (epilimnion); during mixis, the integration was over the entire water column. Wet weight (WW) was calculated according to the geometric shape of the species [19], assuming that the density of the algae is one.
© Copyright Policy
Related In: Results  -  Collection

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

life-05-00418-f001: The annual maximum biomass of (a) Nostocales species, (b) Chroococcales species and (c) Peridinium and total biomass in Lake Kinneret, 1969–2014. The biomass measurements were based on phytoplankton counts in samples collected from various depths at biweekly intervals. Depth-integrated biomass was done as described by Berman and Pollingher (1974) [17] and Zohary (2004) [18]. During stratification, the depth-integrated biomass was calculated from zero to mid-thermocline, between 15 and 20 m (epilimnion); during mixis, the integration was over the entire water column. Wet weight (WW) was calculated according to the geometric shape of the species [19], assuming that the density of the algae is one.
Mentions: The long-term record of cyanobacteria in Lake Kinneret comprises 41 species and genera from three main orders; Nostocales, Chroococcales and Oscillatoriales. Members of the latter order were sporadically observed [20]. Variations in the relative species composition and domination on multiannual scales (Figure 1) demonstrate that the annual total cyanobacteria biomass can be divided into three periods: (1) from 1969 to the mid-1980s; (2) from the mid-1980s to the mid-1990s; and (3) from 1994 to present. During the first period, cyanobacteria comprised a small fraction of the total phytoplankton biomass (the annual average from 1969–1985 ranged between <0.1% and 0.9% of the total biomass), and Chroococcales species dominated the cyanobacterial assemblage. From the mid-1980s to the mid-1990s, the cyanobacteria population was substantially suppressed. During that period, the dominating taxa were P. gatunense during winter-spring. Aulacoseira granulata, which reached a biomass of 182 g m−2 in 1988, and chlorophytes (Pediastrum sp., Coelastrum sp., Scenedesmus sp. and Tetraedron). Since 1994, blooms of Microcystis (Chroococcales) and blooms of Aphanizomenon ovalisporum and Cylindrospermopsis raciborskii (Nostocales) intensified [11,18,21,22]. Here, we bring a short description of the common and most abundant cyanobacteria species observed in Lake Kinneret.

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