Riding his bike to work in the Netherlands’ Zeeland province, Tjeerd Bouma passed fields of pear and apple trees. His mind wandered. As a coastal ecologist at the Royal Netherlands Institute for Sea Research (NIOZ), Bouma had been searching for a material with which to create artificial reefs in the Wadden Sea, a system of intertidal sand and mud flats that’s been heavily modified by humans over thousands of years. He realized that pear trees could be used for this very purpose.

“They have these nice branching structures and complexity, and they’re biodegradable,” Bouma told Mongabay. Moreover, Bouma knew that fruit trees in orchards had a limited life span. Once pear trees reach 25 to 35 years of age, they no longer produce enough fruit to be profitable, so farmers cull them, turning them into firewood or wood pellets or simply sending the trees to landfills. But maybe, Bouma thought, they could be repurposed to create reefs.

Bouma shared his idea with colleagues, including Jon Dickson, a researcher at NIOZ whose current work focuses on artificial reefs and marine environmental restoration. Dickson believed the idea had merit, since pear trees have the structural complexity needed for an artificial reef and because planting “tree reefs” would mimic a natural process.

“If we look at history … wood came down rivers all the time and got spit out at sea,” Dickson said. “Lots of it washed up, but lots of it sank, too. We have fossil records dating back to the Jurassic [period] about marine wood deposits and the animals that live on it, so we know that wood has been going out to sea for hundreds of millions of years” […]

Read more on Mongabay.