Resilience
Resilience is defined as the ability to withstand and recover quickly from any disturbance; both quick (hurricanes) and slow (sea level rise). The Down East community of Harkers Island has embodied resilience for many generations. Dating back to 1899, when the San Ciriaco Hurricane hit the Outer Banks resulting in one of the worst storms the U.S. Atlantic has ever seen, this community was washed out of Shackleford Banks. Yet, in the face of such disaster, this unwavering group of fishermen and whalers grabbed what they had left and made their way across the sound and inland to Harkers Island and other Down East communities, where their decendants reside today. Since then, the Down East people have used this generational strength to withstand any threat that comes their way.
Today, the Harkers Island community faces a new threat, and its effects present a haunting visual. What was once a coastline of lively and vibrant pine trees is now rapidly replaced with ghost-white trunks, exposed roots, and fallen limbs. It is no secret that the community will persevere in the face of this change; however, we need a better look at the entire picture to do so.
What is a Ghost Forest?
Ghost forests are patches where previously healthy coastal forests are being lost and converted to salt marsh habitats due to repeated exposure to saltwater. Coastal forests are important because they act as a barrier to protect coastal communities from storms and slow erosion. Species such as the bald cypress loblolly pine trees can handle some saltwater, making them good warriors against salt spray and waves. However, these trees need freshwater too, and when they are flooded too frequently or their root system is surrounded by too much saltwater, they can't handle it. This results in gray patches of dead forests and stumps that indicate that a once-healthy forest has retreated inland.
What Causes Ghost Forests?
Ghost forests are created by the gradual rising of sea levels associated with the effects of climate change. You may be wondering, 'How does this happen exactly?' Well, as air temperatures warm all over the planet, ocean water expands, requiring more space. Warming temperatures can also lead to ice glaciers and sheets that usually sit on top of the land, melting and breaking off into the ocean. In turn, both of these factors can cause sea levels to rise.
So how does this connect to the ghost forests on Harkers Island? With a higher sea level, the surge from storms will come up further than it used to. The same applies to the high tide that rolls in every 12 hours: over time that tide will gradually rise higher. This process of saltwater moving further inland is called saltwater intrusion. Saltwater intrusion negatively impacts sensitive species within coastal forests, such as the pine trees mentioned before, which cannot tolerate high salinity levels. These species will eventually die, and their remains make up the ghost forest.
Extreme weather events, such as hurricanes, can also increase rates of ghost forest formation, as flooding is happening more rapidly and intensely. Droughts can also lead to increased salinity and tree mortality.
What is Saltwater Intrusion?
We touched on this phenomena above, but let's take a deeper dive...
Saltwater Intrusion and Ghost Forests Example:
Saltwater intrusion is the process by which higher salinity water moves further inland due to rising sea levels and extreme weather events such as hurricanes and droughts. This comes back to the higher tides and more significant storm surges that seep further inland to those species that can't handle that much saltwater.
So we know that saltwater intrusion is killing the trees, but what does that mean to us? Well, directly underground is something called an aquifer. An aquifer is a layer of rock that holds fresh water, and this is where most houses on Harkers Island derive their well water from. When saltwater intrusion happens, this aquifer is gradually contaminated with saltwater, which can contaminate your drinking water.
Ghost forests show us that saltwater intrusion is happening. The further inland the ghost forest stretches, the more saltwater could contaminate the groundwater.
How to Spot a Ghost Forest
1. Tree Discoloration?
Have the tree trunks turned a pale white or gray color instead of the typical brown?
2. Losing Bark and Branches?
Are there no leaves? Are there few or no branches left? Is the bark patchy and peeling off?
3. Intuding Marsh Grass?
Are there any signs of marsh grass starting to grow around the base of the tree? Are there signs that the habitat is transitioning from coastal forest to marshland, such as greater abundance of grasses and shrubs as opposed to trees?
Impact of Ghost Forest Formation on…
Culture and History
The Down East communities are rich in culture and history. Families have lived here for generations and have formed strong bonds with the coast that represent their maritime heritage associated with fishing, hunting, and boat building. Ghost forests serve as a symbol of losing this place, where they dedicated time to hard work and family bonding.
Real Estate
One side effect of ghost forests is the transition from forested land to wetlands. Wetlands are less suitable for growing a garden and are typically unsafe for construction. In addition, as the proximity to wetlands increases, residential property values may be affected.
Plants and Animals
Plant communities are impacted by saltwater intrusion. Freshwater dependent plants are replaced by salt-tolerant marsh plants. These marsh plants are typically grasses and shrubs, and establish themselves in the understory of trees. This process is aided as trees die off, allowing more light to reach the ground.
As the ecosystem transitions from forest to marshes, not just plants are impacted. Some costal forest bird species have to migrate inland as the forest canopy disappears and is replaced by ground vegetation. This means the habitat for birds who prefer the forest canopy are disappearing. Ghost forests support a different set of species, such as woodpeckers who nest in tree cavities and prefer the dead trees created by ghost forests. Eventually, these species will also migrate as the trees fall into the new marshlands.
"It is born in the people of the original Core Sound bankers who are innately aware of their surroundings -- its beauty and its challenges -- to learn, accept and respond to the realities of sea level rise as the impacts continue to become part of daily life."
- Karen Amspatcher, Coresound and Waterfowl Museum and Heritage Center Executive Director, and Harkers Island Native
A Look into the Past
Harkers Island is located in the southernmost portion of the NC Outer Banks: a dynamic system consisting of barrier islands and critical estuarine habitat. Dramatic changes are part of dynamic systems but even more so when threatened by climate change and rising sea levels. Looking at aerial photographs compiled over time, we can see just how much the coastline of Harkers Island has changed over the last several decades.
This video compares the Harkers Island coast in 1978 to 2019. The red line represents the coastline in 1978, and the timelapse depicts the change in land over the past ~40 years.
The first image is an arial image of the Harkers Island coast courtesy of the Cape Lookout National Seashore (US National Park Service). The second image is a satellite view of the Harkers Island coast in 2019 courtesy of Google Earth.
Solutions: Prevention and Mitigation
So, we've identified what a ghost forest is, how they're caused, and why we should take them seriously; what's next? Although it would be nice if there were a step-by-step action plan to reverse ghost forests and saltwater intrusion effects, that's sadly not the case. But not to fear! There are a few things that the Down East Community can do to prevent further ghost forest spread and respond best to the effects of its drivers.
1. Implementing Living Shorelines
A living shoreline; usually made of natural materials like wetland plants, sand fill, and rock, can be used to reinforce the barrier between coastal and terrestrial environments. By recreating or enhancing the previously-healthy coastal habitat, living shorelines can actually buffer against flooding and erosion! Because living shorelines are comprised of natural materials, they grow and can become stronger over time. Another plus is that they tend to cost less than hard shorelines (AKA seawalls) when it comes to installation and maintenance, according to NOAA (National Oceanic and Atmospheric Administration) NOT sure if we should include. Some other benefits to living shorelines include: purifying water, storing carbon, and attracting wildlife.
2. Participating in Citizen Science
If you found this glideshow through the Chronolog Station, then you have already participated in citizen science! if not, go check out the Chronolog station located on the Soundside Loop trail behind the Visitor Center at Cape Lookout National Seashore’s Headquarters on Harker’s Island.
Future map/Image of Chronolog
The Chronolog is an extremely important tool that helps researchers monitor Harkers Island ghost forests through a time-lapse compilation of images taken by people just like you. Contributing to research through citizen science is a great way to make a personal impact on remedial efforts, and it can be fun!
3. Climate Change Remediation
Target the problem at the source. If you make efforts towards stopping climate change, it will slow sea-level rise, and if sea level rise subsides, saltwater intrusion will too! Try to reduce your personal carbon dioxide emissions. CO2 is one of the main greenhouse gasses that warm the planet, so taking personal steps to lessen this amount can add up!
Here are some easy things you can do that can end up making a big difference:
- Walking and biking when you can, to reduce your vehicle emissions. Biking emits zero pollutants, and it can be pretty fun!
- Try cutting out meat in one of your meals each week. If every American implemented one plant-based meal into their diet one week, it would be like taking 500,000 cars off the road.
- Invest in energy-efficient appliances, and weatherize your home. Replacing an old washer or refrigerator? Look for that Energy Star label! According to the Natural Resources Defense Fund, efficiency standards for appliances and products have kept 2.3 BILLION tons of of carbon dioxide out of the air.
- Participate in a town hall and ask your elected officials about their climate change policies.