As more and more people move to the coast, there is a constant struggle between development and protecting our coastal environment.

We all need to be working together to resolve the complex issues facing our North Carolina coast. Currently, this is not happening. Standing at the forefront between future development and the environment is the United States Army Corps of Engineers. The Corps is an engineer formation of the United States Army that has three primary missions: Engineer Regiment, Military Construction and Civil Works. These engineers build sea walls, renourish beaches, dredge inlets and give approval for others (towns and contractors) to perform activities such as the construction of terminal groins and creating new or restoring existing navigational channels by dredging. Another important mission is aquatic ecosystem protection and restoration. Therefore, and unfortunately, the future of our coastal environment is not in the hands of natural resource agencies and coastal scientists, but rather in the hands of engineers.

A generalized difference between engineers and coastal scientists is that scientists are trained to understand natural systems while engineers are trained to manipulate the natural systems. Protecting our coastal environment should require and combine both; the engineers’ practical problem-solving expertise along with the scientists’ expertise on how nature works. Unfortunately in problem solving, coastal engineers usually ignore the scientific concerns expressed by coastal scientists. It is this scientific uncertainty about natural events that can undo engineering interventions on the coast. In some cases, the consequences of intervention can take several decades to become apparent. This makes it difficult for the general public to access applications and make the connection between Corps intervention and consequences it triggers.

The Corps recently approved permits to place a terminal groin on the east end of Ocean Isle Beach and to perform new dredging to create a navigational channel in Jinks Creek at Sunset Beach. What does the science say about these two projects? What are the probable future consequences the taxpayers, residents and vacationers of Ocean Isle Beach and Sunset can expect?

Example 1. A terminal groin was approved for the east end of Ocean Isle Beach because the beach in that area is eroding. A groin is a long, solid structure that extends out into the water, perpendicular to the shoreline, and is typically made of cement or rock. Groins prevent erosion by trapping the longshore transport of sediment on the updrift side of the groin. Wave actions naturally remove sand from the beach and this sand enters the longshore current and moves the sand parallel to the shoreline. In Brunswick County beaches this sand moves east to west. Terminal groins act like dams, physically stopping the movement of sand. Groins do result in a buildup of sand on the upstream side of the groin, which is precisely what they are designed to do. However, the areas further downstream are cut off from the natural longshore transport thereby triggering more erosion.

Figure 1 demonstrates that once the first groin is constructed additional groins will be required to protect the beach downstream. This figure shows a series of six groins along a beach. Notice the erosion downstream from the groin at the top of the figure. 

On the other hand, soft stabilization such as beach nourishment, dune building, marsh systems and living shorelines should be considered before intervention with hard structures like terminal groins. Soft structures will not subject the beaches of Ocean Isle Beach and eventually Sunset Beach to a series of terminal groins.

How can placing a terminal groin on Ocean Isle Beach be considered beach restoration when it will trigger more erosion? If a terminal groin is placed on the East end of Ocean Isle Beach how many future, additional groins will be needed? What will be the cost? Who will pay?

Example 2. The Corps recently approved a Sunset Beach permit to create a new navigational channel in South Jinks Creek, which is a naturally occurring shallow water tidal creek that has never been dredged before. Figure 2 shows the location of Jinks Creek on the East end of Sunset Beach. Jinks Creek via Tubbs Inlet connects the Atlantic Ocean to the Atlantic Intracoastal Waterway. Just west of South Jinks Creek are the feeder canals and Canal Bay area. North Jinks Creek is surrounded by salt marshes which have been designated primary nursery areas and thus cannot be dredged. The town originally proposed to dredge all of Jinks Creek along with the feeder/canals and Canal Bay but, due to the high density of oyster beds North Jinks Creek was removed. 

Scientists have clearly expressed concerns that dredging a 1,700-foot-long, 80-foot-wide navigational channel that is 5 feet mean low water level in South Jinks Creek will increase the risk of flooding and erosion after storm surges on the east end of Sunset Beach. The engineering consulting firm Moffat and Nichol hired by the town said their computer modeling indicates there will not be any increase of flooding or erosion. The engineers state their modeling data estimates the maximum flood increase to occur in South Jinks Creek may be equal to an order of only 1/64 of an inch.

North Carolina State University professor emeritus Dr. Len Pietrafesa, the Burroughs and Chapin Scholar at Coastal Carolina University, Dr. Paul Gayes, a professor of marine science and geology at Coastal Carolina University and executive director of the Burroughs and Chapin Center for Marine and Wetlands at Coastal Carolina University, and Dr. Shaowu Bao, associate professor at the Coastal Science Center at Coastal Carolina University, using the very same computer program but with additional input data, disagree.

According to Dr. Pietrafesa, the study done by the consulting firm did not take into account nonlocal forcing due to wind set up at the mouths of tidal inlets, such as Tubbs Inlet that connects to South Jinks Creek, which are stochastic, or cannot be precisely predicted, and can overwhelm the amount of volumetric transport that can be driven into the system, particularly for South Jinks Creek. There already is major erosion in this area as shown by the extensive network of sandbags where Tubbs Inlet joins South Jinks Creek. If the three independent academic scientists are correct, the property owners in this area can expect more sand bagging on the rest of South Jinks Creek and possibly in Canal Bay. Sandbags are most likely only a temporary fix. What is next, other hard structures like bulkheads or sea walls? What will happen to the property values in this area?

After the initial dredging, maintenance dredging will be required every few years to keep the unnatural channel open. What will be the escalating costs of the required additional dredging? Who will pay for them?

Another consequence of dredging South Jinks Creek is that it will increase the sediment load deposited in North Jinks Creek. This will bury the high density of oyster beds. Oysters are a “keystone” species, meaning their removal could dramatically change the ecosystem. What will be the ecological impact on North Jinks Creek and the surrounding primary nursery areas? How can dredging a shallow-water tidal creek that has never been dredged before be considered aquatic ecosystem protection and restoration? 

In addition, the increased sediment load deposited in North Jinks Creek will most likely require that North Jinks Creek be dredged followed by more maintenance dredging. Again, what will be the escalating costs and who will pay? 

The civil works side of the Corps’ mission includes:

1. Navigation.
2. Flooding and storm protection.
3. Aquatic ecosystem restoration.

If you protect wisely you don’t have to restore. They are naturally a function of each other. If we are serious about attempting to protect what little natural environment, we have left we must convince the engineers of the Corps to collaborate with the independent academic scientists who have dedicated their professional lives to studying our coast. True collaboration leads to win-win solutions.

To stimulate discussion and debate, Coastal Review welcomes differing viewpoints on topical coastal issues. See our guidelines for submitting guest columns. The opinions expressed by the authors are not those of Coastal Review or the North Carolina Coastal Federation.

The economy will reopen! The questions are the timing and mechanism. To answer these questions requires a better understanding of how the virus functions and spreads the disease.

COVID-19 has never been seen before this outbreak. As a result, there are many details about the infection that remain unknown. Will COVID-19 go away soon? What can we learn from history?

The impact of the 1918 Spanish flu continues today. Descendants of the virus can still be found in pigs. Ever since a lab accident in 1977, nearly all human cases of influenza A have been caused by Spanish flu viral descendants.

The Spanish flu was the most devastating pandemic ever recorded. What are the similarities between the Spanish flu and the coronavirus pandemics? Both diseases appear to come from animal sources.

Research suggests H1N1 Spanish flu virus came from birds. Scientists suspect an animal originally hosted the COVID-19 coronavirus strain before it started to infect humans but, to date the animal has not been identified. We also know the Spanish flu became much more dangerous after an apparent mutation. Strains of coronavirus are known to mutate relatively easily. A third comparison shows how quickly both viruses spread. Spanish flu infected an estimated one-third of the global population. COVID-19 has spread rapidly from its late December origin in China. It is now found on all continents except Antarctica. The State of New York alone currently has more infections than any other country.

The graph below demonstrates the three waves of the 1918 influenza pandemic. The second wave was much more deadly than the first or third wave.

The first wave resembled a typical flu epidemic; those most at risk were the sick and elderly, while younger, healthier people recovered easily. Historians now believe that the fatal severity of the Spanish flu’s second wave was caused by a mutated virus spread by wartime troop movement. The second wave made adults who were young and fit more vulnerable. Will we experience a second wave of the COVID-19 infections if we open the economy to soon?

The current prerequisite for reopening the economy appears to be the development of an antibody test. Such a test will identify individuals who have been infected and therefore have antibody protection against the virus; the first group to go back to work. The antibody test will detect the body’s immune response to the infection but does not detect the virus itself. In order words, a positive antibody test indicates coronavirus infection in the past; it does not rule out the possibility that the virus is still present in individuals who test positive for the antibody.

Before an individual with a positive antibody test is allowed to go back to work, a real time polymerase chain reaction test (RT-PCR) should also be performed. The RT-PCR test will detect the presence of viral RNA. It is an extremely sensitive test that can detect as little as one virus particle in swabs from inside the mouth or nose. Since there are now 91 cases in South Korea where patients have recovered from the viral infection, but still test positive for the virus, it makes the TR-PCR test a critical part of the equation to open the economy.

Another problem with the antibody test is to classify individuals to go back to work is that we currently don’t know how long the COVIP-19 antibodies will protect against reinfection. In the case of measles, the protection lasts a lifetime but, this is not the case with some other viruses.  More research needs be performed on the longevity of the COVID antibody before allowing people to go back to work.

Finally, before stay-at-home orders are lifted, we need to improve our diagnostic capabilities so that scientists can calculate the R_o value of the COVID-19 virus. R_o indicates how contagious an infectious disease is. It’s also referred to as the reproduction number. As an infection spreads to new people, it reproduces itself.

R_o indicates the average number of people who will catch a disease from one contagious person. It specifically applies to a population of people who were previously free of infection and haven’t been vaccinated; this is the case for the COVID-19 virus. If the R_o is less than 1, each existing infection causes less than one new infection. In this case, the disease will eventually die out. If R_o equals 1, each existing infection causes one new infection. The disease will stay alive and stable, but there won’t be an outbreak or an epidemic. If the R_o is greater than 1, each existing infection causes more than one new infection. The disease will spread between people, and there may be an outbreak or epidemic.

What is the R_o value of the COVID-19 virus? Since the COVID-19 virus is still new, scientists are working on establishing its R_o value. Researchers who have calculated an R_o for the current outbreak have had to make assumptions. As the virus spreads more information will be made available and the number is likely to change. The current estimate of the World Health Organization is that COVID-19 has an R_o value between 2.0 and 2.5. The R_o value for the 1918 Spanish flu pandemic was estimated to be between 1.4 and 2.8. Clearly, before the economy is reopened, the R_o value for COVID-19 must be 1 or lower. Otherwise we will not stop the spread of the virus.

Once individuals that are immune to reinfection are given permission to go back to work, the Spanish flu pandemic demonstrates that social distancing must be enforced. Unfortunately, there are several industries where social distancing will be difficult to enforced. They include travel by airlines/mass transit, attending church services, movie theaters, sporting events, conventions, funerals, school, etc. Thus reopening the economy must start with industries where social distancing can be enforced.

The potential reopening of the economy is a very complex issue. We need a lot more information regarding the virus before considering the time and mechanism to reopen the economy.

To stimulate discussion and debate, Coastal Review Online welcomes differing viewpoints on topical coastal issues. See our guidelines for submitting guest columns. The opinions expressed by the authors are not necessarily those of Coastal Review Online or its publisher, the North Carolina Coastal Federation.