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> Obviously hydroelectricity is massively damaging to ecosystems. Can you elaborate? To me it always seemed like we're basically replacing a river with a lake,

by c7b 4y ago

> Obviously hydroelectricity is massively damaging to ecosystems. Can you elaborate? To me it always seemed like we're basically replacing a river with a lake, which doesn't seem so bad. Sure, it requires adjustment to a new equilibrium, but why is the dam lake ecosystem strictly worse than the river one? Genuinely curious, it always seemed to me that the discussion around hydropower seemed to focus solely on what is lost from the river ecosystem, without discussing what might be gained by a lake ecosystem.

buttercraft 4y ago
For example, salmon migrate from the ocean to their spawning grounds in river beds. They have to go up over dams on special fish ladders. Most don't make it. Sockeye salmon were almost completely wiped out but are starting to bounce back. This also affects other species like bears which depend on these salmon runs before hibernation.
idiotsecant 4y ago
changing the flow characteristics of a river is a massively disruptive event, not just for the species in the water but also the animals that rely on tertiary characteristics and effects of that river. It changes the erosion patterns and sediment carrying capacity of the stream, it changes the seasonal flows that ecosystems have come to rely on, it changes nutrient transport, changes water temperature, changes oxygen content, and a million other things that make the stream less compatible with certain species and more compatible for others. Best case this results in loss of biodiversity, worst case it results in spread of invasive species that have even further impacts on an even wider swatch of the ecosystem. It doesn't make the ecosystem go away, it just changes it to a less settled one - generally when that happens the complexity of the ecosystem goes down until natural selection can catch back up and everything adapts to fill the same niches again, which is not a fast process. It's hugely disruptive to ecosystems.

by c7b 4y ago

buttercraft 4y ago

For example, salmon migrate from the ocean to their spawning grounds in river beds. They have to go up over dams on special fish ladders. Most don't make it. Sockeye salmon were almost completely wiped out but are starting to bounce back. This also affects other species like bears which depend on these salmon runs before hibernation.

idiotsecant 4y ago

changing the flow characteristics of a river is a massively disruptive event, not just for the species in the water but also the animals that rely on tertiary characteristics and effects of that river. It changes the erosion patterns and sediment carrying capacity of the stream, it changes the seasonal flows that ecosystems have come to rely on, it changes nutrient transport, changes water temperature, changes oxygen content, and a million other things that make the stream less compatible with certain species and more compatible for others. Best case this results in loss of biodiversity, worst case it results in spread of invasive species that have even further impacts on an even wider swatch of the ecosystem. It doesn't make the ecosystem go away, it just changes it to a less settled one - generally when that happens the complexity of the ecosystem goes down until natural selection can catch back up and everything adapts to fill the same niches again, which is not a fast process. It's hugely disruptive to ecosystems.