Phanerogams or higher plants like Zostera noltii (eelgrass) constitute a group of plants characterised by an external structure in which the root, stem, leaves, flowers and fruits with their seeds can be clearly distinguished. Although it is basically a terrestrial group, some species have adapted to the underwater environment where they play an important role as sediment stabilizers and primary producers.

Furthermore, its dense formations or meadows constitute one of the most productive marine ecosystems as they are an indirect source of food and a place of refuge or breeding ground for many organisms, besides participating actively in the nutrient cycle.

The dramatic reduction in the surface area occupied by different marine phanerogams observed worldwide in the second half of the 20th century in particular, plus the acknowledged importance of the ecological functions fulfilled by their meadows in estuary and coastal ecosystems, have led to deep concern among scientists and to the carrying out in recent years of many projects designed to re-establish these marine meadows.

The transplanting of adult plants is one of the various methodologies to revive a meadow. Through the specific case of the estuaries in the Basque Country, a piece of work conducted by AZTI-Tecnalia presents a methodology to carry out a suitable selection of a candidate zone for receiving the transplants, since this selection is regarded as one of the key points for achieving success in this type of action.

Right now, the only phanerogam that forms marine meadows in the Basque Country is Zostera noltii, with the presence of intertidal populations in three of the 12 Basque estuaries (Oka, Lea and Bidasoa). After analysing and assessing the different environments offered by the remaining 9 estuaries as well as the ecological state of their waters, it was concluded that the estuary that offers the greatest chances of success for the transplanting of this phanerogam is that of Butroe, followed by Oria and Urola.

Read the study in the Revista de Investigación Marina (Journal of Marine Research)