Monitoring the impact of stone weirs on biodiversity

Monitoring the impact of stone weirs on biodiversity

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In 2022, MedINA and WWF Hellas, in collaboration with Boulouki, installed more than 30 traditional stone weirs along the course of the Kavouropotamos stream, Paros, Cyclades, Greece. The action was implemented in the context of adaptation of the Cycladic ecosystems -as well as their communities- to climate change and was supported by the Paros Water Supply and Sewerage Company, the Municipality of Paros, and the Mediterranean Islands Collective (MIC) initiative, funded by the MAVA Foundation.

Freshwater crabs were found during the sampling in a single locality of Kavouropotamos, justifying thus its Greek name, since “Kavoúri” in Greek means crab while “potamòs”, river!
© Sakellarakis F.-N./MedINA.

Almost a year after collecting the baseline data and installing the stone weirs along Kavouropotamos, it is time for the first evaluation of the positive impacts of this nature-based solution (#NbS)!

One of the stone weirs constructed in Kavouropotamos in 2022. The presence of aquatic emergent vegetation both above and below the weir is evident. More than 20 plants species were recorded at this location alone! © Sakellarakis F.-N./MedINA.

So, a few days ago, the MedINA team, together with botanists from the University of Göttingen, Germany, visited Paros, carrying out fieldwork to record the flora and vegetation of the area!

MedINA team during vegetation sampling in Kavouropotamos. Photograph by Ute Bergmeier.

In total, more than 10 vegetation plots were assessed along the stream, both upstream and downstream of the stone weirs, for a comprehensive understanding of their effects on key biodiversity parameters.

All the results will soon be available to the research community through a report led by the Hellenic Institute of Speleological Research, with reference to the impact of the stone weirs on the vegetation as well as on arthropods and reptiles!

Stay tuned!

The project is part of the overall programming of the Mediterranean Islands Collective (MIC) initiative, launched and supported by the MAVA Foundation to develop an action plan for the sustainability of Mediterranean islands.

Small pond created upstream of the stone weirs in which a species of the genus Chara was observed. Although are not vascular plants, but multicellular green algae, they are important bioindicators and their discovery this year was their first observation in the last two years of data collection! © Sakellarakis F.-N./MedINA.
The vegetation of the stone weirs can be classified under the Habitat Type “3290 – Intermittently flowing Mediterranean rivers of the Paspalo-Agrostidion”, according to Annex I of the Habitats Directive 92/43/EEC. It is worth mentioning that in the latest national report on the Conservation Status of Species and Habitat Types of the Habitats Directive, the Conservation Status of the Habitat Type 3290 was found to be Unfavorable – Inadequate (U1) thus further underlining, the positive benefits of the project for a rare vegetation type in the Cyclades region! © Sakellarakis F.-N./MedINA.