Seasteads may have a major advantage for mariculture. One reason why the sea is a much harsher environment for life than land is that when things die on land, their remains are readily available for scavenging. When things die in the ocean, they sink to the ocean floor, removing useful resources from the food chain. Natural upwelling zones, which constitute only about 1% of the oceans surface, produce approximately half of the worlds fish. Once OTEC is a viable energy source, or perhaps earlier if wave-powered pumps such as the Isaac's Pump are used, seasteads will be bringing nutrient-dense water to the surface as a side effect of generating power. This can be used as the base for a food chain of aquatic life. { expand this discussion? Need references }