Plastic waste has become a main pollutant of riverine and marine environments, with the former acting as a critical route from land to sea. The Ozama River located in the >3 million-inhabitant city of Santo Domingo, Dominican Republic, is considered one of the largest contributors of terrestrial macroplastic waste to the Caribbean Sea. Modeled emission estimates show high uncertainty due to the lack of consistent, long-term field data. Mounted monitoring cameras (n = 8) across two main river bridges at 5.5 km and 2.2 km upstream of the river mouth validated current flux and emission models of macro debris (>5 cm). Analysis of 380,000 images collected over 383 days starting February 2022 shows a 2-fold increase and a 1.5-fold increase in debris concentrations and mass fluxes, respectively, in the downstream direction. The increased debris detection downstream is associated with the influx from riparian ravines (cañadas) and illegal waste dumping along the stream. A daily average of 0.9 tons of anthropogenic "trash" flux was detected at the downstream location, resulting in over 300 tons and 10 million macro particles annually. This mass flux is at the low range of previous model estimates. The mass flux of organic materials, such as water hyacinths, was up to ten times higher than the trash fluxes. The data shows a positive correlation between organic and non-organic waste peaks, reflecting the findings of previous studies. Future data can support determining uncertainty and offers an assessment of discrete environmental and anthropogenic peak events.

Primary Presenter: Winston Gonzalez, Instituto Tecnologico de Santo Domingo (INTEC) (winston.gonzalez@intec.edu.do)

Authors:

Winston Gonzalez, Instituto Tecnologico de Santo Domingo (INTEC)  (winston.gonzalez@intec.edu.do)

Rafael Garcia, Instituto Tecnologico de Santo Domingo (INTEC)   (rafael.garcia@intec.edu.do)

Renata Correia, The Ocean Cleanup  (renata.correia@theoceancleanup.com)

Stijn Pinson, The Ocean Cleanup  (stijn.pinson@theoceancleanup.com)

André Vollering, The Ocean Cleanup  (andre.vollering@theoceancleanup.com)

Carlos Sanlley, Instituto Tecnologico de Santo Domingo (INTEC)  (carlos.sanlley@intec.edu.do)

Thomas Mani, The Ocean Cleanup  (t.mani@theoceancleanup.com)