A German meta-analysis suggests boating, shoreline fishing and swimming may be damaging freshwater ecosystems. 

German scientists have brought together and re-analysed the data from 94 previous studies looking at damage to freshwater ecosystems from recreational activities around the world.

They say that boating had the most consistently negative effect on the environment, affecting individual plants and animals, whole populations, and even whole communities of organisms.

Impacts were assessed at three levels of biological organisation (individuals, populations, and communities) for several different species and lifeforms. 

Impacts of boating and shore use resulted in consistently negative, significant ecological impacts across all levels of biological organisation. 

The results were less consistent for angling and swimming. Strongest negative effects were observed in invertebrates and plants. 

Impacts of water-based activities on freshwater ecosystems varied significantly by activity type, species affected and their ecological responses. 

The authors recommend that conservationists should avoid bluntly assuming all recreation activities impact freshwater ecosystems the same way.

The full study is accessible here.