Catalan Water Research Institute research and innovation for the sustainable use of water

A study reveals that the Llobregat and Besòs rivers dump approximately half a ton of plastic into the sea a year

Wednesday, 19 February 2020

A recent study on the quantification of floating waste at the mouths of the Llobregat and Besòs rivers, close to the city of Barcelona, ​​estimates that the two rivers dump between 0.4-0.6 tonnes of plastic per year into the Mediterranean Sea.

The study has been carried out by the IDAEA-CSIC , ICRA , CEIMAR-INMAR-Universidad de Cádiz , Comisión Europea-JRC and the Asociación Paisaje Limpio . And it is part of the RIMMEL project , directed by the Joint Research Center of the European Commission, and created due to the need to quantify the contributions of floating waste that reach the sea from continental waters.

Since most marine litter comes from land, rivers are a key piece in quantifying the amount of waste that ends up in the sea. The aim of the research has been to collect the largest amount of data possible, to create a statistical model of the most common floating waste, which allows the development of future strategies to mitigate the problem of marine waste.

Both rivers were sampled from October 2016 to September 2017. The methodology used is based on the observation of the surface water sheet for 30 and 60 minutes a week, from an elevated position close to the mouth of the river. The objective is to identify and classify, using a specific app for this study, floating debris greater than or equal to 2.5 cm (called macroresidue), according to the list of items described in the Framework Directive on Marine Strategies.

Throughout the year, 684 items were identified between the two rivers and, according to the guidelines of the RIMMEL project, they were classified into the following categories: plastic, paper, metal, rubber, textile and wood. The results were very similar in both rivers, and plastic was the most frequent category in the floating debris observed; 67.7% in the Llobregat river and 50.5% in the Besós river and the most frequent waste is packaging, plastic parts, plastic bottles and plastic bags. Items that match those of the 17 rivers of the Mediterranean region, sampled through the RIMMEL project.

To obtain the results, an extrapolation of the sampled width to the total width of the river has been carried out and the sampling time has been normalized to express the characterized waste flow per hour. It is estimated that approximately 0.4-0.6 tons of plastic are dumped during a year by these two rivers, into the Mediterranean Sea.

The possible sources of pollution of the observed floating waste arise fundamentally from urban centers and leisure activities and, to a lesser extent, from industry.

This data is important, but it is still a first contact. Research must continue to identify the causes and sources of the opposite waste in the Llobregat and Besós rivers, and put into practice different methodologies that allow the data provided by this study on floating macrowaste to be compared, and that, in addition, allow quantifying the non-floating waste that can be found in the river bed.

The research article can be consulted under the title “Riverine anthropogenic litter load to the Mediterranean Sea near the metropolitan area of ​​Barcelona, ​​Spain” in the scientific journal Science of the Total Environment .

About Clean Landscape

Non-profit association created in 2004 with the aim of raising public awareness of the problem of uncontrolled dumping and care for the environment.

The Limpio Landscape Association will continue with macro-waste sampling work in the Llobregat River, in a work framed within the ANAVES de Libera project, with the aim of quantifying, identifying sources of origin and finding a solution to the waste problem.

About IDAEA-CSIC (Barcelona)

The Institute of Environmental Diagnostics and Water Studies (IDAEA) is a multidisciplinary research institute founded in 2008 that brings together a wide range of specialized knowledge in environmental sciences. In particular, the Department of Environmental Chemistry is a diverse and highly interdisciplinary group of scientists whose research focuses on the processes that influence the chemical speciation of natural systems, the mobility and fate of pollutants in the environment (water , air, soil, crops and biota), the processes that affect the toxicity and bioavailability of pollutants and many aspects of their rehabilitation.

About ICRA (Girona)

The Catalan Water Research Institute (ICRA) is a multidisciplinary water research center created on October 26, 2006 by the government of the Generalitat de Catalunya, within the framework of the Catalan Research Centers Program ( SEARCH).

The research carried out at ICRA concerns all aspects related to water, especially those related to its rational use and the effects of human activity on water resources.