It's a hidden global change: away from the public eye, residues of medicines in water have been causing increasing disruption. They can kill aquatic animals, and play havoc with their food web and reproductive cycle. An international team of researchers led by the NIOO makes an urgent case for better wastewater treatment and biodegradable pharmaceuticals.

Massive growth of submerged aquatic plants can be a nuisance, especially in summer. It's up to water managers to limit the inconvenience for swimmers, boats and fishermen in a way that is both responsible and cost-effective. Michiel Verhofstad defended his PhD thesis this week on the 'root' causes of the problem, and how best to tackle it.

Swimming in nature is healthy. A group of British researchers have started a project to spread the word.