Seagrasses represent one of the most important ecosystems of the Mediterranean Sea, contributing to biodiversity conservation, carbon storage, and sediment protection from erosion. Their stability is seriously threatened by climate change, particularly by rising sea temperatures. The CYMOT project focuses on investigating the response of the seagrass Cymodocea nodosa and its associated microbial community to extreme heatwaves in the Ribnjak Bay (Šćuza) on the southern coast of Istria — a unique and sensitive shallow-water system exposed to above-average summer temperatures.

The main objectives of the project include:

(1) assessing the health status and spatial distribution of C. nodosa meadows,

(2) analyzing changes in the microbial community within the plant’s rhizosphere under thermal stress,

(3) investigating the release of organic matter with surface-active properties (surface-active substances – SAS) as potential early bioindicators of stress, and

(4) developing a hydrographic model to simulate scenarios for mitigating the negative impacts of climate change.

Throughout the project, C. nodosa meadows will be mapped over a three-year period, and measurements will include hydrographic conditions, plant biometry, nutrient concentrations, dissolved organic matter, surface-active substances, as well as geomorphological and ecological characteristics of the sediment, together with the abundance and structure of the microbial community. Sampling and measurements will be conducted over three years, while final analyses and modeling will be carried out during the fourth year.

The project will contribute to a better understanding of climate-induced changes in coastal ecosystems and support the development of strategies for their protection and effective management.