Home / Science / Lake Divided: Phosphorus's Algal Bloom Secret Revealed
Lake Divided: Phosphorus's Algal Bloom Secret Revealed
4 Sep
Summary
- Lake 226 was split to test nutrient impacts on algal blooms.
- Phosphorus addition caused a severe bloom in one basin.
- The experiment influenced global phosphorus regulations.
In 1973, a groundbreaking experiment at Canada's Experimental Lakes Area (ELA) used an impermeable curtain to divide Lake 226 into two basins. This allowed researchers to isolate the impact of specific nutrients on lake ecosystems. One basin was enriched with nitrogen, carbon, and phosphorus, while the other received only nitrogen and carbon.
The results were striking: the basin with added phosphorus experienced a massive algal bloom within two months, transforming its water quality. In stark contrast, the other basin remained largely unchanged from its pre-experiment condition. This visually compelling demonstration highlighted phosphorus as the primary driver of freshwater eutrophication and algal blooms.
The findings from the Lake 226 experiment had profound policy implications. The clear evidence provided by the ELA helped overcome industry opposition and finalize stronger phosphate bans in laundry detergents and water management legislation worldwide. This research was instrumental in improving sewage treatment and water quality guidelines, influencing investments in municipal treatment plants across North America to remove phosphorus from effluent.
The ELA, established in 1968 and managed by the International Institute for Sustainable Development (IISD) since 2014, continues to conduct whole-ecosystem research. The Lake 226 experiment, along with ongoing research like that on Lake 227, has consistently reinforced the importance of controlling phosphorus to protect freshwater resources.
