Algal growth and sediment properties
There was a highly significant correlation between EC andSelenastrum capricornutum populations (r2 =
0.87) (Figure 5). This implies that the sediments with high salinity
supply enough P for the growth of the algae. The sediment of the present
investigation had an EC of only 0.23 to 1.22 dS m-1and our data suggest that an increasing EC might lead to larger growth.
This larger growth could be related with greater P availability, but it
might also be due to other factors that affect algal growth. Several
earlier studies also showed an increase in P bioavailability with
increasing salinity (Jordan et al., 2008; Hartzell et al., 2010; Li et
al., 2015); however, this salinity is in the range that does not hinder
organism survival (EC = 0.46 ± 0.28). From the negative relationship
between algae growth and both CCE and pH could be deduced that these
sediment properties restricted the degree of eutrophication (Figure 5).
Therefore, Selenastrum capricornutum is not calcium-loving and
occurs in calcareous streams with deposits of travertine and tufa. There
is also a positive relationship between OM and the algae growth, what
might indicate the availability of organic P for the growth of algae.