How Science is Defending Our Coasts from Climate Change Using Plant DNA

These days, climate change is a bit of a foregone conclusion. Even if global efforts to reduce carbon emissions materialize in a significant way, there may be little we can do to prevent an increase in average temperatures by four degrees Celsius by 2100. To put that into perspective, temperatures have only risen by about .8 degrees Celsius over the past 100 years. Our continental ice reserves are melting at a rapid rate, and scientists believe the oceans have already absorbed up to 90 percent of the carbon being emitted, making them increasingly acidic.

Image courtesy Michael Kane.

The bottom line here: Ecology is changing for our coastlines, as well as for the sea oats there to protect them. (Never heard of sea oats before? They’re the quietly regal, reedy plants swaying in the backdrop of your breezy beach vacation.) These unassuming plants may not strike the average person as heroic, but their role in preserving the delicate ecosystem of our coastlines means they serve as the defenders of billions of dollars and thousands of lives, human and otherwise.

Here’s how: When hurricanes barrel from the Atlantic to the Gulf with high-mile winds and pelting rains, these modest sea plants stand their ground, anchoring the dunes around them. As the rain pelts down in torrents and the winds attempt to bulldoze everything in their path, these stalky reeds prevent the sands from eroding entirely into the sea. The soil gathered around their stems is dispersed toward the ocean line, filling in the gaps left by the storm, resurfacing along the beach, allowing life to go on.

But given strong enough wind or rain, sea oats weakened by acidic waters are ripped from their homes, and the dunes they were holding in place collapse. During tropical storms or hurricanes, entire dune areas can be flattened, and the sea oat populations there demolished. When those populations cease to exist, the cycle is interrupted and future dunes cannot form, leaving the ecosystem and the construction behind it vulnerable to the elements.

While sea oat plants may look the same to the layperson, each area of beach has its own population, specifically adapted to withstand the elements on that particular bit of earth. Their unique differences can make or break the ecosystem each plant calls home. Plus, even healthy sea oats are incredibly slow-growing, releasing seeds rarely, though once mature, sea oats are very hardy, built to handle full sunlight, strong winds, salt sprays, and drought conditions.

Many dune areas are able to be reseeded naturally very slowly—but the tourism industry, beach homes, and marine lives depending on their protection don’t have much time to spare. Florida alone brings in tens of billions of dollars in revenue from out-of-state beach tourists, according to the Department of Environmental Protection, and when a storm impacts the coast, billions are lost from dwindling tourist numbers and reconstruction costs. More than 150 hurricanes and 250 tropical storms have hit the state since we started keeping records in the 1800s, and the change in weather patterns means more storms than ever are predicted each year on average in the coming decades.

Such storms leach out sand, leaving the beaches devastated in their wake. Three-hundred and twenty-eight miles of Florida’s sandy beaches are eroding enough to threaten existing developments and recreational areas. That’s about 40 percent of the state’s beaches. Currently, Florida spends $30 million a year replenishing the beaches with trucked-in sand. Without sea oats, that new sand will likely be blown away in the next storm.

Researchers gather data from sea oats. Image courtesy Michael Kane.

But what might happen if we could bring sea oats back from the future—or a population back to life from the brink of extinction—to thwart the demise of our changing coastline ecosystem? That’s what a team of scientists at the University of Florida (UF) is trying to find out.

Hundreds of miles away from any coast, scientist Michael Kane cuts tiny plant shoots in his lab in Gainesville, Florida, meticulously analyzing the sea oats’ DNA. He and fellow researchers at UF are honing in on a way to save sea oat populations. The slight man with a graying mustache doesn’t look the part of a savior. But Kane’s meticulous manipulation of their structure and location turns him into the general of this natural army. He’s developing a genotype library, which means Kane takes samples of various sea oat populations and cultivates them in the lab through a process called “micropropagation” that’s more than a little reminiscent of Jurassic Park.

Transferring cultures. Image courtesy Michael Kane.

In essence, Kane rapidly multiplies stock plant material to produce offspring, then arranges and stores the new plants based on their natural location and DNA makeup. First, his team selects plant shoot tips from native populations along the coast. They then bring the samples back to their lab, where they perform genetic analysis. Next, they slice the plant shoot tips and put them in a cryogenic vial. After all water has been removed from the specimen and put in a protectant to prevent ice crystal formation, the scientists plunge the vial into liquid nitrogen.

A frozen shoot tip can be left like this indefinitely, until it is needed, then be thawed out and cloned before plants are placed in the greenhouse. With these sample populations on hand, a sea oat population in Florida wiped out by a storm can be revived. Kane’s team would simply need to locate the correct genetic mix, thaw the shoots necessary, and begin to grow them in greenhouses for replanting. From start to finish, the process of defrosting and micropropagating takes a little more than five months.

Up until now, researchers doing micropropagation have had to keep sea oat populations continuously growing to sustain populations, which takes a lot of time, space, and resources. With the addition of cryogenic freezing, the plants remain in suspension until they’re needed, freeing up lab and greenhouse space, as well as researchers’ time, for other endeavors.

While the most efficient and successful way to propagate sea oat plants is via seeds collected from native populations, when large-scale storms wipe out entire populations, Kane can now use his “germplasm library” (a collection of living genetic resources such as seeds or tissue maintained for the purpose of plant breeding, preservation, and other research uses) and tissue culture to help restore them.

Michael Kane.

Kane also has a rather adventurous new grant proposal on the table which would allow him and his fellow researchers to examine on a small scale the possibility of planting the dunes with sea oats—from the future.

“Right now, we would replant the populations in the wild with the genotypes that best match them now,” Kane said. “What we are going to do is experimentally replant the populations with the genotypes that would fit best there in the future. The question is, do we modify the composition of the population to reflect the changes that are coming? Or do we plant out the old population that was evolved for conditions that no longer exist?”

In other words, we could possibly re-plant the dunes not with exact replicas of the populations wiped out, but with populations carrying small changes adapted precisely to what scientists believe the environment will be like in the future—thus creating populations that will be sustained, even in the face of future ecological damage.

"What happens in 100 years when the coastline as we know it is underwater? Has all this work been for nothing? Of course not. Knowledge is knowledge," Kane said. "But the fact remains, in 100 years, Florida will not look like the Florida we know today."

Sea oats grown in Kane's lab. Image courtesy Michael Kane.

With the next grant proposal, Kane is hoping to study the genetics of sea oats from as far north as North Carolina to gauge their degree of cold tolerance along the eastern coastal regions. While dune erosion and rebuilding has been occurring for tens of thousands of years, and works on its own as a natural cycle, humans have now built their lives to exist right next to these dunes, so it’s imperative that we protect them. Since we’ve modified our coastline dramatically, it’s up to us to develop methods that will result in optimal dune stabilization.

Kane views his work as an effort in bio-engineering, and those in coastal areas are starting to agree, treating the coastline as infrastructure. At this juncture—with climate change already affecting so much of our beach space—Kane’s work might be the coasts’ best shot at long-term survival.

Illustration by Brian Hurst