Massive algal blooms where there are no fish need give no one nightmares. Once we are electrolysing lots of water for the hydrogen, dissolving the waste oxygen

Massive algal blooms where there are no fish need give no one nightmares. Once we are electrolysing lots of water for the hydrogen, dissolving the waste oxygen in river outflows could start to save the current dead zones. But restricting over-fertilization would have a bigger effect.