By Stefanie Jackson – Scientists at the University of Virginia’s Eastern Shore research site, known formally as the Anheuser-Busch Coastal Research Center, are learning about climate change and sea-level rise and their effects on coastal habitats, marine life, and ultimately, people living on the Eastern Shore and around the globe.
Their work is part of the Virginia Coast Reserve’s Long-Term Ecological Research program, which has continued for more than 30 years.
The program was established in collaboration with The Nature Conservancy and is funded by the National Science Foundation.
The public was invited to an open house at the research center Jan. 7, where they enjoyed complimentary wine and light refreshments in a casual setting while meeting researchers and learning about their scientific findings and the resulting real-life applications.
Highlights of the event included a presentation on marine heatwaves – significant increases in water temperatures – which have occurred sporadically over the last 35 years. Water temperatures above 28 degrees Celsius (82 degrees Fahrenheit) are dangerous to marine plants.
Scientists are concerned. Even though the marine heatwaves have not increased in intensity, they are becoming more frequent.
Marine heatwaves that began in 2012 and continued through 2017 were responsible for the massive killing of seagrass meadows off Eastern Shore of Virginia coasts in 2015. The record high temperatures were recorded at a buoy in Wachapreague.
Researchers at the Oyster lab are participating in the restoration of the seagrass beds, which are the preferred habitat of some bivalves like bay scallops.
Scientists studied how the seagrass restoration may affect populations of certain types of marine life. For example, since the restoration began, researchers have found more clams living inside the seagrass than outside, but more blue crabs outside the seagrass than inside.
The most populous fish in the seagrass are silver perch and anchovies.
The restoration is important in light of climate change, because seagrass – as well as salt marsh – helps remove carbon dioxide from the atmosphere.
The researchers have studied how marshes are migrating further inland due to sea-level rise. This is a problem because the marshes are migrating into forests, where there is less light. The marsh grasses are getting enough light to grow but not to reproduce, meaning less genetic diversity and less chance of prolonged survival.
One experiment found that marsh grasses flower seven times less when they are covered by cloths providing 10% shade.
But the study of marsh migration has also led to findings that could benefit Eastern Shore farmers. Researchers discovered that native plants like salt marsh hay can be used to mitigate saltwater intrusion on farmlands.
Salt marsh hay draws salt out of the soil and releases the salt through its leaves, much like salt is removed from the human body through sweat.
Marshes play an important role in mitigating climate change because they store carbon more effectively than forests do.
Trees store carbon mostly in their trunks, so when trees are cut down or die naturally, carbon is released back into the atmosphere. Trees can be killed by saltwater intrusion, leaving behind a phenomenon called ghost forests.
But marshes store carbon in the soil, where it remains trapped and eventually becomes oil and coal.
Plants remove carbon dioxide from the atmosphere during photosynthesis, the process by which plants use sunlight to make their own food. But researchers want to know just how much carbon dioxide salt marshes are removing from the atmosphere, and can the marshes use the carbon dioxide fast enough to outgrow rising sea levels?
One-third of the Eastern Shore’s marshes were created within the last 100 years. One way everyday citizens can help save these marshes is by creating living shorelines, which provide protection against erosion using natural elements.
Traditional, manmade barriers like seawalls and bulkheads have fallen out of favor with the scientific community. These barriers actually lead to the loss of marshes.
Scientists now recommend planting marsh grasses and building oyster reefs to protect shorelines.
Oyster reefs help prevent erosion and also provide habitats for marine life. In one study, when oyster reefs in the water were exposed or barely submerged, they reduced wave heights by 40%. When oyster reefs were fully submerged, they reduced wave heights by less than 10%.
Marshes dampened waves by 91% over a 20-meter section at Fowling Point, a research location a few miles east of the Birdsnest area.
Researchers have visited Fowling Point since 2007 to measure how much carbon dioxide salt marshes remove from the air, using a method called eddy covariance.
Studies show a reduction of carbon dioxide in the atmosphere when more sunlight is present, during the day and in the summer, when more photosynthesis occurs.
But eddy covariance is less effective at tracking the movement of carbon dioxide when marshes are underwater at high tide. In spring 2020, researchers will add solar induced fluorescence to their repertoire, allowing them to measure photosynthesis.
It will be the first time this technology has ever been used in an aquatic environment, and it will happen on the Eastern Shore.
The researchers also use well-recognized technology, like drones, which are used to study changes in habitats such as coastal salt marshes, barrier islands, oyster reefs, and mudflats.
The data collected by the drones is used to create digital elevation models of the areas and study the land’s responses to storm disturbances, erosion, and sea level rise.
One of the highlights of the Jan. 7 open house was the opportunity for guests to create their own elevation models in an interactive “virtual sandbox” in a darkened lab room. The sandbox featured a projector that displayed an elevation map on the sand, which changed in real time as guests dug their own mountains, valleys, lakes, and rivers.
Guests could also “make it rain” by holding their hands one foot above the sandbox and watching the virtual water pooling below.