With much valuable farmland being used to produce bioethanol, the search for biofuel should turn to the world's oceans and to seaweed, Israeli researchers say.

Scientists at Tel Aviv University said marine macroalgae, common seaweed, can be grown more quickly than land-based crops and harvested as fuel without sacrificing usable land.

Seaweed can be grown unobtrusively along coastlines and can also clear the water of excessive nutrients caused by human waste or aquaculture that disturb the marine environment, zoology professor Avigdor Abelson said in a TAU release Monday.

Researchers said they are developing methods for growing and harvesting seaweed as a source of renewable energy.

While land-bound sources are renewable, there is concern converting land from food crops to biomass crops such as switchgrass for alternative fuel will limit food resources and drive up costs, the researchers said.

Seaweed could be a renewable energy source that doesn't endanger natural habitats, biodiversity, or human food sources, they said. (UPI)