The biological assessment of rivers, i.e., their assessment through the study of aquatic communities (e.g., fish, macro invertebrates, algae and plants) provides information on the integrated effect of multiple stressors over time, and is essential to evaluate the health of rivers and to establish recovery measures. In this study, we review the existing bioassessment programs in the world. We show that, despite the large number of studies done in the past decades, the bioassessment for rivers it is not globally implemented, and only a very small fraction of the world impacted rivers are subject to rehabilitation.  Our results reveal also a poor biological condition in many rivers around the world and a striking and worrying loss of aquatic biodiversity. Finally, we make recommendations to move towards successful restoration programs, which include being based on clearecological objectives and on a solid ecological knowledge of the systems; pre- and post- assessment with key biological indicators; and being considered a priority by decision makers, involving the citizens, and receiving adequate funding.

Read the full study  here:

Feio, M.J.; Hughes, R.M.; Callisto, M.; Nichols, S.J.; Odume, O.N.; Quintella, B.R.; Kuemmerlen, M.; Aguiar, F.C.; Almeida, S.F.P.; Alonso-EguíaLis, P.; Arimoro, F.O.; Dyer, F.J.; Harding, J.S.; Jang, S.; Kaufmann, P.R.; Lee, S.; Li, J.; Macedo, D.R.; Mendes, A.; Mercado-Silva, N.; Monk, W.; Nakamura, K.; Ndiritu, G.G.; Ogden, R.; Peat, M.; Reynoldson, T.B.; Rios-Touma, B.; Segurado, P.; Yates, A.G. The Biological Assessment and Rehabilitation of the World’s Rivers: An Overview. Water 2021, 13, 371. https://doi.org/10.3390/w13030371

Text written by Maria João Feio and edited by Clara Ruiz and Félix Picazo