As atmospheric CO2 levels rise, so too do those in the sea, leading to ocean acidification that outpaces that of any other time in tens of millions of years.

Waza National Park in West Africa is a refuge to many endangered and vulnerable species. Walk through the grounds and you may see red-fronted gazelles grazing or giraffes sauntering between trees in search of foliage. Head to the park’s perimeter, though, and you may see a less serene scene: elephants raiding local farmers’ crops.

We have a lot of stake in the coast. Coastal waters are where we host fisheries, build homes and turn to for tourism and recreation. So how should coastal communities, which comprise nearly 40 percent of the world’s population, safeguard against flooding, erosion and violent weather? Marine scientist Michael Beck suggests the solution is growing right beneath some waves and, in many cases, it has been waiting there for thousands of years.