Washington State Lake Protection Association - WALPA

https://wix.to/ylCUJUW
Every summer, a barge is piloted up the Dworshak reservoir and liquid nitrogen fertilizer is added into the water. And no — that's not an environmental violation. It's an EPA-permitted ecosystem restoration project.

Dworshak Reservoir is in north-central Idaho. Spring runoff delivers a pulse of nutrients into the system — but the flows are so high and the water so cold it moves through the reservoir faster than the biology can use it. This low residence time means the spring nutrients are flushed out before phytoplankton can exploit them. By summer, when productivity should peak, there is not enough of the nutrient NITROGEN to keep the reservoir’s food web functioning correctly. By correctly we mean that the phytoplankton production that occurs no longer supports suitable zooplankton or fish populations. Another complication is that when the nitrogen runs short in Dworshak, the algae that takes over are blue-green cyanobacteria that can produce toxins and the zooplankton can't eat. This increase in cyanobacteria taxa short-circuits the carbon pathway all the way up to the fish.

So ammonium nitrate is added in carefully calculated doses. They are targeting a specific nitrogen-to-phosphorus ratio in the epilimnion to favor edible flagellates and green algae over cyanobacteria. This does two things. 1) it increases the productivity of the system and 2) reduces the risk of toxic blue-green algae blooms.

In the 14 years of this project the zooplankton biomass has almost doubled compared to the levels seen before the project started.

Reservoirs are controversial and full of societal and environmental tradeoffs. They do not behave naturally but there are things that can be done to help the ecosystems function better within reservoirs. That's the goal of this project — and the data says it's working.

https://wix.to/07nkNJ2
Every summer, a barge is piloted up the Dworshak reservoir and liquid nitrogen fertilizer is added into the water. And no — that's not an environmental violation. It's an EPA-permitted ecosystem restoration project.

Dworshak Reservoir is in north-central Idaho. Spring runoff delivers a pulse of nutrients into the system — but the flows are so high and the water so cold it moves through the reservoir faster than the biology can use it. This low residence time means the spring nutrients are flushed out before phytoplankton can exploit them. By summer, when productivity should peak, there is not enough of the nutrient NITROGEN to keep the reservoir’s food web functioning correctly. By correctly we mean that the phytoplankton production that occurs no longer supports suitable zooplankton or fish populations. Another complication is that when the nitrogen runs short in Dworshak, the algae that takes over are blue-green cyanobacteria that can produce toxins and the zooplankton can't eat. This increase in cyanobacteria taxa short-circuits the carbon pathway all the way up to the fish.

So ammonium nitrate is added in carefully calculated doses. They are targeting a specific nitrogen-to-phosphorus ratio in the epilimnion to favor edible flagellates and green algae over cyanobacteria. This does two things. 1) it increases the productivity of the system and 2) reduces the risk of toxic blue-green algae blooms.

In the 14 years of this project the zooplankton biomass has almost doubled compared to the levels seen before the project started.

Reservoirs are controversial and full of societal and environmental tradeoffs. They do not behave naturally but there are things that can be done to help the ecosystems function better within reservoirs. That's the goal of this project — and the data says it's working.

https://wix.to/93PJ4bn

In 1967, the world's top lake scientists couldn't agree on what was killing lakes like Erie. Was it phosphorus? Nitrogen? Carbon? Nobody could agree — and nobody invited the Swiss-Italian limnologist who had already figured it out. Richard Vollenweider spent years reviewing data from lakes across Europe and North America and built the first mathematical model linking phosphorus loading to algal blooms. His 1968 report — never formally peer-reviewed — quietly became the foundation of lake management worldwide. By 1972, his model had shaped the Great Lakes Water Quality Agreement between the U.S. and Canada. The lakes that recovered did so because someone eventually listened.

https://wix.to/XXKJWMS