Coral Reefs: A Wonder in Crisis
Technical Briefing for NR 1114
Eli Archer
Problem Statement:
Due to my love of the ocean and my major, watershed management (and the movie Finding
Nemo), I plan to research the effects of climate change on the health of coral reefs worldwide. I will look
at the causes of coral bleaching from multiple angles with a focus on global warming along with refuting
research on bleaching due to natural cyclical events. The death of coral has massive ecological and
economic effects worldwide, from the death of species that attract fishermen and tourists, to the
desertion of many species altogether and the rise of unfavorable species.
Introduction:
All around the world, our most biologically diverse ecosystems are facing a grim future. Global
warming, harmful fishing practices and pollution are poisoning our planet and taking a heavy toll on
coral reefs. With 19 percent of the world’s reefs already destroyed and 15 percent seriously threatened
with loss in the next 10-20 years, the reefs simply cannot handle the amount of stress humans are
putting on them (NOAA). The gradual warming of the Earth is slightly raising sea temperatures, causing a
massive coral bleaching. This is when corals turn white due to stress-induced death of their
Zooxanthellae, or living energy supply that gives them their golden brown color. Land-based sources of
pollution including those of agriculture, coastal development, and overpopulation result in the release
of toxins, pathogens and sediment into coastal waters. These pollutants enter local watersheds,
smothering and killing the living corals. Diseases and predators like the crown of thorn starfish are also
found guilty in destroying reefs. With their predators in decline, they feed freely on the coral.
Destructive fishing practices such as the use of trawling nets and anchors dragging across the sea floor
leave the corals ravaged. Native reef fish are also being over harvested and are constantly victims of bycatch fishing. With these negative effects comes a direct link to coastal economies; as the reefs continue
to suffer, so do the people who depend on them. Today, reef researchers provide several ways to save
the World’s most valuable aquatic ecosystems, all of which involve asexual coral fragmentation:

Asexual coral fragmentation
o Land based nurseries for later fragmentation
 Frozen coral bank
o Field based nurseries (aquatic)
 Coral suspension over the seafloor
 Mid-water coral nursery
 Floating Coral Tree
Issues and Solutions:
A simple cost effective solution along with other simple daily changes can help to restore and
preserve the world’s reefs. The gradual restoration of reefs through the process of reef transplantation
is an inexpensive and effective way of healing our world's complex marine ecosystems. Since degrading
one reef to restore another is not an option, coral fragments produced by storms could be used to
revive reefs. The stray fragments including Elkhorn, Staghorn and Finger corals would be secured to
dead corals using nylon cable ties (Ward, Garrison). Though somewhat logical, this method of
restoration is not very efficient as the fragments would have to be sought out before being
transplanted, making it rather labor intensive. A commonly asked question concerning this solution is;
will the transplanted corals have enough time to establish themselves before being bleached like their
fellow organisms? In other words, will the proposed solution work? To answer this question and many
others, transplantation experiments were conducted on the near shore waters of Virgin Islands National
Park, St. John, and the US Virgin Islands. 60 transplanted and 75 control colonies were monitored for
survival and growth for five years: 1999-2004 (Ward, Garrison). Geological survey scientists, volunteers
from Friends of Virgin Islands National Park and students monitored the colonies monthly and recorded
growth records (Ward, Garrison). Out of the three tested corals, Elkhorn coral was proved to be the only
successful transplant candidate (Ward Garrison). After 5 years of growth, one-fourth of the 135
monitored colonies were able to successfully sustain themselves (Ward, Garrison). The Elkhorn coral
fragments are abundant and easy to find in and around reefs and are especially easy to attach. This
process of transplantation can easily be done by volunteers in communities near coral reefs.
Since this experiment, huge advancements have been made in the laboratory realm of reef
restoration. The task of transplanting corals remains the same, but the method of obtaining the coral is
different. Researchers have taken matters into their own hands by engineering land and field (aquatic)
based coral nurseries where corals are now being asexually reproduced in mass quantities to later be
transplanted back into dying reefs (Nedimyer). When compared, land based nurseries have proved less
successful than aquatic based nurseries, though they both have their pitfalls. Land based nurseries
necessitate a high coral capacity due to limited indoor water space; they have very high maintenance
costs, both equipment and employee related, and are more susceptible to diseases, parasites and
equipment failure (Nedimyer). The main benefit of land over sea nurseries comes with the human
control of environmental conditions as shown here in this unique example of a land based nursery: The
first frozen coral sperm and egg bank was recently established on Coconut Island, Hawaii (“First”). In this
“bank,” sperm samples and fertilized coral eggs are being extracted, frozen and successfully thawed to
produce coral larvae (“First”). This frozen material can be thawed one, 50 or even 1,000 years later to
resurrect a species, or even an entire population (“First”). It’s almost like Jurassic Park for coral reefs.
Between transplantation and reproduction, indoor and field labs are cooperating to restore reefs.
In order to have the coral fragments to rehab reefs, the fragments must be found, or more
commonly grown. There are a few different popular ways to do this. All are have the same underlying
principle of fragmentation for later transplantation, but all vary in design. The first common method is
done by attaching small coral fragments of coral to wire racks just above the sea floor to let them grow
(Ellis). Another design involves suspending the corals from horizontal ropes running across the surface of
the sea by wire or other ropes so they may dangle to the sea floor (Bowden). This method lets the corals
grow freely, however, is likely to cause entanglement with marine life. The mother of all solutions lies
with a very innovative design for coral growth called the coral tree nursery. This simple yet highly
effective design was invented to facilitate the growth of Staghorn corals, but can be used to grow many
coral species (Adams). The coral tree nursery was invented to resolve some of the issues with the other
nursery solutions. It resembles a tree-like structure with many perpendicular branches jutting off from
the main shaft, where corals are to be attached using wire (Nedimyer). The vertical column design of the
tree makes for great use of space as compared to previous designs. It features a subsurface floatation
device and an anchor or tether for sea floor attachment, depending on the bottom terrain, making for
fluid mobility with tides and storm generated wave surges (Nedimyer). What makes the coral tree
nursery so practical is its easy installation and transportation, along with its low cost. One tree can be
installed by a single person on a small boat and costs as the structure itself is made only of PVC, rope,
wire and small amounts of steel for extra support (Nedimyer). Some advantages of the Coral Tree
Nursery are its minimal impact on sea floor habitats, its portability, adjustable height to grow corals in
various water temperatures, low underwater volume to reduce catching of marine life, low surface area
for algal growth, and very low maintenance (Nedimyer). This nursery is the most efficient and cost
effective solution in reef restoration to this date (Nedimyer).
Field based nurseries use either stray fragmented corals, coral pieces a few millimeters in size
taken from existing reefs, or asexually reproduced lab corals to later be transplanted to a dying reef
(Nedimyer). A reef in Carrizales Bay, Mexico has shown great success with two techniques of coral
transplantation using fragments (Linan). The coral clusters technique uses five to seven coral fragments
joined together by plastic straps, which are then strapped to dead corals for growth (Linan). The other
technique, simple aggregation involves evenly placing individual fragments on the sea floor for growth
(Linan). Both techniques were monitored for 270 days for overall growth, algal growth, disease, and
fusion between fragments (Linan). The fragments used in the coral clusters technique yielded a 95.5
percent survival rate, while the simple aggregation technique showed an 89 percent survival rate
(Linan). The cluster technique showed better stability, but both could be used worldwide for large scale
coral reef restoration (Linan). The restoration of reefs means the stability of a huge reef-dependent
economy.
Conclusion:
These valuable undersea habitats possess great economic, medicinal and environmental value
as they support and protect coastal populations and aquatic species. Approximately 500 million people
who depend on the diverse ecosystems for food, coastal protection, building materials, and income
from tourism will feel the harsh effects of reef decline worldwide (NOAA). This includes the 30 million
who are completely and totally sustained by them (NOAA). A recent estimate gave the total net benefit
of the world's coral reef ecosystems to be $29.8 billion a year (NOAA). Just as reefs provide habitat for
fish species and protection for coastlines, they provide jobs and income for local people and economies
through fishing, tourism and recreation. However, not only do the shallow water corals provide crucial
benefits, but deep sea corals are also found to be increasingly important with the discovery of new
medicines and indicators of past ocean conditions (Coral). Restoring reefs and implementing laws
worldwide to better protect reefs is no small task, but it must be done to keep these incredibly
important ecosystems alive and functioning. The Coral Tree Nursery, frozen coral banks, and other
fragmentation projects are doing their job to sustain corals, keeping aquatic species, the economy and
aquatic fun alive.
Works Cited
Adams, Jake. Staghorn Coral Tree Nursery by Coral Restoration Foundation takes a page from
aquarium culture techniques, (2011). Reefbuilders. Web. 5 Dec. 2012.
Bowden-Kerby W. A., 2001 Coral transplantation modeled after natural fragmentation
processes: low-tech tools for coral reef restoration and management. PhD thesis, University of Puerto
Rico at Mayaguez 195pp.
Coral Reefs: The Importance of Coral Reefs, (2012). Marinebio. Web. 5 Dec. 2012.
Ellis S., Ellis E., 2001 Recent Advances in Lagoon-based Farming Practices for Eight Species of
Commercially Valuable Hard and Soft Corals - A Technical Report. CTSA Publication No. 147., 63 pp.
First Frozen Coral Sperm and Egg Bank Created. Our Amazing Planet. Tech Media Network,
2010. Web. 27 Nov. 2010
Linan-Cabello, Marco A. (2011) Acclimation in Pocillopora spp. during a coral restoration
program in Carrizales Bay, Colima, Mexico: Marine & Freshwater Behavior & Physiology Vol. 44 Issue 1,
p61, 12p. Ebsco Host. Web. 28 Nov. 2012.
Nedimyer, Kenneth, Kevin Gaines, and Stephanie Roach. "Coral Tree Nursery: An Innovative
Approach to Growing Corals in an Ocean-based Field Nursery." Aquaculture, Aquarium, Conservation &
Legislation International Journal of the Bioflux Society 4.4 (2011): 442-46. EbscoHost. Web. 28 Nov.
2012.
NOAA Coral Reef Conservation Program. National Oceanic and Atmospheric Administration,
June 14 2010. Web. 19 Nov. 2010.
Selig, Elizabeth R; Casey, Kenneth S; Bruno, John F (2010) New insights into global patterns of
ocean temperature anomalies: implications for coral reef health and management. Global Ecology &
Biogeography 19: 397-411
Ward, Garrison. Transplanting Coral Fragments to Damaged Coral Reefs in a National Park Planting the Seeds to Recovery? USGS Science for a Changing World. St. Petersburg Coastal and Marine
Science Center, March 10 2010. Web. 19 Nov. 2010
Worldwide Destruction of
Coral Reefs
Coral
bleaching
And proposed solutions
Reduce
Greenhouse
gasses
Climate Change/ Global
Warming
Rising ocean temperatures
due to unsustainability and
irresponsibility
Uneducated tourists
and divers abusing
coral and fish species
Economy
involved in
reef
tourism
Overfishing reef
fish
Tourism
Fishing
Solutions
Asexual
reproduction
for coral
fragmentation
Land-based
nurseries
Coral
suspension
Coral Tree
Nursery
Trolling large
lines and nets
through reefs
Money saved
on pesticides
if banned in
coastal areas
Pesticides/over-fertilization
Fieldbased
nurseries
Mid-water
coral nursery
Sediment kills corals
causing decline in native
species
Algae from
sediment