The alga Ulva lactuca (Ulvaceae, Chlorophyta) as a bioindicator of trace element contamination along the coast of Sicily, Italy.

The marine environment is subjected to ever-increasing levels of contamination, especially along the coastal areas with urban and industrial activities. Consequently, monitoring campaigns on large scales should be conducted on a regular basis for a better management of marine ecosystems. This study tested the capacity of the green alga Ulva lactuca to act as a bioindicator of trace elements along the coasts of Sicily (Italy). The concentrations of the metals Cd, Cr, Cu, Ni, Pb and Zn were analyzed in samples of water, sediments and U. lactuca thalli, which were collected in ten different sites at diverse levels of human impact. The results showed that U. lactuca can accumulate essential and non-essential elements at similar concentrations. The analysis of trace elements showed also that the metal content in U. lactuca is significantly correlated with the levels of trace elements in water and sediments. U. lactuca fits numerous features that make it one of the best bioindicators of marine pollution, also thanks to its worldwide distribution and capacity to accumulate trace elements under toxic conditions. The use of U. lactuca should be encouraged to set up large-scale monitoring programs, especially in highly impacted seas like the Mediterranean where U. lactuca is widespread.

Air quality biomonitoring through pollen viability of Fabaceae.

In this study, pollen viability and germination of three plant species, Cercis siliquastrum L., Robinia pseudoacacia L., and Spartium junceum L., belonging to the Fabaceae family, was evaluated in sites with different intensity of road traffic, constantly monitored with continuous analysers for air pollutants (carbon monoxide (CO), sulphur dioxide (SO(2)), and nitrogen dioxide (NO(2))) by the Municipality of Catania. Two sites, in which road traffic was absent, were selected, too. The percentages of viable pollen by 2,3,5-trypheniltetrazolium chloride (TTC) test ranged from 59.0 to 90.2 % in C. siliquastrum, from 61.5 to 83.5 % in S. junceum and from 67.5 to 84.3 % in R. pseudoacacia. The percentages of germination varied from 41.0 to 72.7 % in C. siliquastrum, from 42.0 to 64.7 % in S. junceum and from 38.3 to 66.3 % in R. pseudoacacia. The highest percentages of viable pollens were found in no-road traffic stations by either TTC or germination tests, while the lowest values were detected in a site characterised by heavy road traffic. In the monitored period (2007-2009), pollen viability, germinability and tube length of C. siliquastrum resulted in a significant negative correlation to CO, SO(2) and NO(2), whereas data from TTC and germination tests on S. junceum and R. pseudoacacia pollens were not well correlated to air pollutants. The results showed that pollen viability, germination and tube growth in C. siliquastrum were affected by air pollution. S. junceum and R. pseudoacacia were not very influenced by air pollutants, suggesting a different pollen sensitivity of these species.