Alice Rotini - FedOA - Università degli Studi di Napoli Federico II

MATERIALS AND METHODS
Ria Formosa is a shallow mesotidal lagoon on the South coast of Portugal, (fig.
2.3) characterised by large intertidal flats with a salt marsh community that covers
ca. 43% of the lagoon’s area.
Fig. 2.3. Ria Formosa lagoon (from Santos et al., 2004, modified).
The average water depth is less than 2 m and the tidal height varies from a
maximum of 3.7 m in spring tides to a minimum of 0.4 m in neap tides. This results
in the flushing of most of the water volume in each tidal cycle (Andrade, 1990),
thereby imposing an intense exchange of materials between the Ria and the adjacent
coastal waters. The lower intertidal zone is dominated by meadows of Z. noltii
distributed within a bathymetric range of about 2 m that alternate daily periods of
immersion and air exposure (Santos et al., 2004).
Sample handling
Immediately after sampling, P. oceanica plants were washed in distilled water
and rhizomes separated from leaf shoots. Rhizomes and leaves were cleaned with a
blade to remove epiphytes, sheets and cortical tissues (to avoid metal contamination
a ceramic knife was used to clean material for metal content analysis). Cleaned
rhizomes and leaves were frozen in liquid nitrogen and then stored separately at -80
°C until chemical analyses. It was only in the last sampling campaign (2010) that has
been possible to wash and immediately freeze the biological material in liquid N2
after collection,. This is an important practice to better preserve biomolecules.
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