NEWS: TETHYS4ADRION in Action: Spring Monitoring on the Neretva Pilot River

On May 18-19, 2026, project partners from the Institute of Oceanography and Fisheries Split, City of Metković and City of Čapljina carried out spring monitoring campaign on the Neretva Pilot River.

This campaign, which will be conduced four times a year, once in each season is supposed to equip researchers with answers to the following questions. What kind of litter floats down the Neretva River and is deposited along its banks? How does it move along the river, and where does it end up? How much of it is there? How do seasonal weather conditions affect those phenomena?

Partners selected six locations along the Neretva River, three in Croatia and three in Bosnia and Herzegovina. Namely, they worked at the mouth of the Neretva, where it flows into the Adriatic Sea, in the settlement of Krvavac, on the bridge in the centre of Metković, on the bridge in Čapljina, and in the settlements of Žitomislići and Ševaš Njive.

Following the methodological steps agreed at the project level, they collected microplastic samples from sandy sediment, as well as macrolitter samples from the riverbanks. From the bridges, they observed floating litter, recording the frequency of litter influx, as well as its shape, size, type, and floating velocity.

This time, unlike during the winter monitoring and sampling campaign, the Neretva flowed more calmly and the river level was lower. As a result, the amount of floating and stranded litter was also smaller. Nevertheless, litter is still present. As it travels along the Neretva, a river approximately 230 kilometres long, the litter becomes trapped in the dense vegetation downstream of Metković, just before the river flows into the sea.

The activity was coordinated by Pero Tutman and Dubravka Bojanić Varezić from the Institute of Oceanography and Fisheries in Split.

Comprehensive data on micro-, meso-, and macrolitter in the Neretva River and along its banks will become available once the monitoring campaigns have been carried out during all four seasons of the year.

Photos: Pero Tutman (Institute of Oceanography and Fisheries in Split).

This has been produced with the financial assistance of the European Union. The content of the website is the sole responsibility of TETHYS4ADRION project and can under no circumstances be regarded as reflecting the position of the European Union and/or IPA ADRION programme authorities.