Translational Fluctuating Asymmetry and Leaf Dimension in Seagrass, Zostera capricorni Aschers in a Gradient of Heavy Metals

摘要

Methodology for measuring translational fluctuating asymmetry (TFA) on leaves of seagrass, Zostera capricorni Aschers has been developed and tested to detect a subtle effect of environmental stress associated with heavy metal pollution on developmental instability. Our analyses showed that concentration of heavy metals (Cd, Pb, Cu, Zn, Se) in leaves and roots of the seagrass were significantly higher in the polluted location than in relatively unpolluted locations. We found significant differences in TFA between different locations, showing that the method is sensitive enough to detect spatial differences even within a rather small water body, but these differences were not associated with a higher concentration of heavy metals, i.e. plants from the polluted location did not show higher TFA. Possibly, seagrass can store heavy metals in their tissues and protect their development from the toxic effect, or the effect of heavy metals in the natural environment is confounded by other environmental factors. At the same time, we found that plants from the polluted location had narrower leaves than in relatively unpolluted ones, which may be caused by heavy metals or associated factors.