Study reveals worrying levels of degradation of rivers worldwide
The research work involved three dozen researchers from all over the world
English version: Diana Taborda
An international study published in the journal Global Change Biology shows worrying levels of degradation in rivers worldwide
The study - led by Maria João Feio, of the Marine and Environmental Sciences Centre (MARE) and of the Faculty of Sciences and Technology of the University of Coimbra - involved three dozen researchers from all over the world and aimed to analyse the biological quality of rivers in the broadest possible way, based on two bioindicators used in river monitoring - benthic macroinvertebrates and fish.
The results of monitoring programmes from 45 countries (64 study regions) from all continents were analysed together, and in particular, a large number of areas of countries belonging to the so-called Global South, "which have the largest reserves of freshwater biodiversity in the world, but which have been less studied or whose data is not known", explains Maria João Feio, adding that these countries include "China, Nepal, Nigeria, Brazil, South Africa, Vietnam or Cambodia".
This research also contains data from areas considered biodiversity hotspots, such as the Amazon, and from countries such as Japan or South Korea, which until now were not accessible to the international community. The scientists have also analysed the influence of human activity and anthropogenic changes on the biological quality of rivers, "which is essential to understand what measures should be implemented at a global level", argues the MARE/FCTUC researcher.
Maria João Feio believes that the findings of this study reflect the "loss of biodiversity of freshwaters, as well as the change in the distribution patterns of species, particularly with the increase of invasive species. All of this changes the functioning of riparian ecosystems, leading to the loss of services provided by these ecosystems to populations (from water supply to climate regulation or disease prevention)".
Therefore, she concludes, it is essential to continue monitoring rivers around the world, "from those where nothing has ever been done to others that have seen their programmes suspended. In addition, it is vital to plan recovery measures and our study shows that establishing protected areas for rivers or improving forests are efficient solutions".
The scientific article is available at: https://onlinelibrary.wiley.com/doi/full/10.1111/gcb.16439.