Coral reefs are some of the most diverse ecosystems in the world. About 25% of the ocean's fish depend on healthy coral reefs. Unfortunately, coral reef ecosystems are severely threatened. Some threats are natural, such as diseases, predators, and storms. Other threats are caused by people, including pollution, sedimentation, unsustainable fishing practices, and climate change, which is raising ocean temperatures and causing ocean acidification. Saving and restoring the world's coral reefs requires a multi-pronged approach that ranges from the local to the global level.

1. Virendra Kumar
PhD 1st Semester
Department- FRM

2. CORAL REEF: Rain Forests of the Sea
• Colonies of various types of reef-building stony hard corals.
• Each coral colony is composed of tiny animals called polyps.
• Each polyp secretes hard calcium carbonate skeleton.
• Calcium carbonate is continuously secreted at the base of the polyps.
• Among the most biologically diverse and economically important
ecosystems.
• Foundation for many marine species.
• Grow in shallow clear water.
• About 4,000 coral reef associated
fish species
• 800 species of reef-building corals
• Coral reefs are often called the "tropical rainforests of the sea" for
their astounding richness of life. Due to their structural complexity,
corals are one of the most productive ecosystems on Earth.

3. SYMBIOTIC RELATIONSHIP OF CORAL WITH ZOOXANTHELLAE
 Most reef-building corals contain
photosynthetic algae, called
zooxanthellae, that live in their tissues.
 Corals and algae have a mutualistic
relationship.
 Coral provides the algae with a
protected environment and
compounds they need for
photosynthesis.
 In return, the algae produce oxygen
and help the coral to remove wastes.
 Zooxanthellae supply the coral with
glucose, glycerol, and amino acids,
which are the products of
photosynthesis.
 The coral uses these products to make
proteins, fats, and carbohydrates, and
produce calcium carbonate.

4. Why are coral reefs important?
• Coral reefs have a value of $9.9 trillion
USD globally.
• Atleast 500 million people relied.
Income
• Cover < 1% of the earth’s surface.
• Home to 25% of all marine fish sp.
Biodiversity
• Treat cancer, HIV, heart disease etc.
Medicine
• 70 million trips supported
annually.
Tourism

5. • Reduce wave energy by 97%
before hitting the shore.
Coastal
protection
• Well managed reefs produce 5-10
tons of fish/km2
Food &
fisheries
• By absorbing Co2 from
atmosphere
Control the
amount of Co2 in
water
• Fix carbon and nitrogen
Recycle
nutrient
• Corals are filter feeder, they
consume particles from water
Water
filtration

6. Coral reef: at risk
• 75% of the world’s coral reefs are currently
threatened.
• 90% of coral reefs will be threatened by 2030.
• 100% of reefs will be threatened by 2050 if we don’t
take action now.
Coral reef alliance, 2022

7. 1%
4%
28%
25%
42%
Critically Endangered
Endangered
Vulnerable
Near Threatened
Least Concern
FAO STATISTA, 2018
Vulnerable
Near Threatened
Endangered
Critically
endangered
Under threat: World coral reef building coral in 2018
Least Concern

8. Human Pressures On Coral Reefs
We know that climate change is
having a huge impact on coral reef
but –what are the human pressure
on coral reefs?
If one meter of reef is lost, flooding may increase by 23%,
impact 62% more people and 90% more property, and
increase damages by $5.3 billion across U.S.
(Reguero et al. 2021)

9. Top 5
Human
Pressure
Industrial
developmen
t 2.60%
Coastal
population
,
19.70%
Fishing
30.80
%
Touris
m
14.60
%
Water
pollution
32.30%
Wildlife Conservation Society, 2022

10. Reason to Threats Coral Reef

11. Warming Temperatures & Coral Bleaching
• Some scientists predict that 90% of global reefs will experience
severe bleaching annually by 2055.
• Most corals have a narrow temperature tolerance.
• Coral bleaching occurs when the symbiosis between corals and their
symbiotic zooxanthellae (tiny algae) breaks down, resulting in the loss
of the algae and a rapid whitening of the coral (thus the term
“bleaching”).
• This is a stress response by the coral host that can be caused by
various factors, but more severe and frequent cases are being caused
by a rise in sea surface temperature.
Bleached coral reef
Healthy coral

12. Illegal Wildlife Trade
• The Aquarium trade is a multi-million dollar industry and is still
growing.
• Tropical fish and corals are removed from reefs, often illegally and
through damaging methods, and enter aquariums all over the world.
• Corals are incredibly sensitive animals and many don’t survive the
journey from reef to tank.
• All hard, or scleractinian, corals have been listed on Appendix II of
Convention on International Trade in Endangered Species (CITES)
since 1985, meaning any trade must be regulated and requires strict
permits.

13. Coral Disease
• Most diseases occur in response to the onset of bacteria, fungi, and viruses.
• Coral disease outbreaks have emerged as a major cause of coral mortality
and reef decline globally.
• They are often linked to declining water quality, overfishing and heat stress
and are now on the rise in areas of the Great Barrier Reef.
• Most common diseases observed on the Great Barrier Reef include white
syndrome, black band and brown band disease.
• Currently estimates that disease accounts for at least six per cent of coral
mortality
Yellow-band disease
black-band disease

14. Crown of Thorns Starfish (Acanthaster planci)
• The Crown of Thorns Starfish is a voracious coral reef predator.
• Populations of the Crown of Thorns have increased since the 1970s and
large outbreaks of starfish can occur wiping out huge tracks of coral reef.
• Few animals in the sea are willing to attack the spiny and toxic crown-of-
thorns starfish, but some shrimp, worms and species of reef fish do feed on
larvae or small adults.
• The decline of these predators, through over-harvesting and pollution, is
one factor contributing to the rise in the population of the starfish.

15. Ocean Acidification
• An increase in the carbon dioxide
levels due to the excessive burning of
fossil fuels has led to ocean waters
becoming increasingly acidic, a process
referred to as ocean acidification.
• This in turn lowers the pH of ocean
water, subsequently affecting the coral
reefs around the world.
• The carbonic acid formed as a result of
this acidification process inhibits the
ability of the corals to build their
calcium carbonate exoskeletons.
• The weaker skeleton makes coral reefs
more vulnerable to diseases and
subsequent destruction of the reef
framework.

16. Over-fishing
• Increasing demand for fish has
resulted in overfishing of many
reef species with a decline in
stocks.
• In addition, Over-fishing of certain
species on or adjacent to coral
reefs can affect the reef’s
ecological balance and
biodiversity.
• For example, over-fishing of
herbivorous fish can lead to high
levels of algal growth.
• majority of marine aquaria are
stocked with species caught from
the wild. Threats from the trade
include the use of cyanide in
collection, and over-harvesting of
target species.

17. Destructive fishing methods
• Fishing with dynamite, cyanide and other damaging methods can
damage entire reefs and is 100% unsustainable.
• Dynamite and cyanide stun the fish, making them easier to catch.
• Damaging such vast areas of coral reef habitat on which the fish rely
will reduce the productivity of the area, with further impacts on the
livelihoods of fishermen.

18. Pollution
• Major pollutants that are released from various sources, mainly due
to careless human activities, pose a serious threat to coral reefs and
the wide array of marine floral and faunal species that are solely
dependent on them.
• These pollutants are either directly dumped into the oceans or by
runoff that flows from the land into the ocean via rivers and streams.
• This leads to the alteration of the landscape and an increase in land-
based pollution sources threatening the health of coral reefs.

19. Algae And Bacteria
• Nitrogen-rich fertilizers, animal wastes, human sewage, and
untreated industrial effluents trigger the explosive growth of harmful
marine algae that blocks the sunlight and starves the water of
oxygen, resulting in an imbalance in the marine ecosystem.
• The excess nutrients also support the growth of life-threatening
microorganisms like bacteria or fungi, that can be pathogenic to the
corals and make them more susceptible to diseases.
• Similarly, hot water released from thermal plants and oil spills can
also be highly detrimental to the health of the coral reefs.

20. Increased Sedimentation
• Sediments can enter water bodies through various coastal
development activities like mining, coastal development, farming,
logging, and building projects, and urban storm-water runoff.
• Sediments that are deposited on coral reefs can smother corals,
thereby impeding coral growth and reproduction, posing a severe
threat to the health of the coral reefs.
• An increased volume of suspended sediments lowers the water
quality and the opaque waters in turn drastically reduce the amount
of sunlight reaching the coral reefs and the lower benthic ecosystems

21. Marine Debris
• Discarded plastic bags, bottles and fabrics also severely damage the
coral reefs.
• It has been projected that by 2025, about 15.7 billion micro-plastics
can come into contact with the coral reefs.
• Marine debris smothers the corals and prevents them from getting
light and food.

22. Irresponsible Tourism
• The brilliant and vibrant hues of coral reef ecosystems attract tourists
in great numbers. Fishing, diving, snorkeling, and boating are some
popular recreational activities that tourists enjoy near the coral reefs.
• Touching the reefs, stirring up the sand and sediments in the seabed,
and collecting corals are some of the activities that damage the reefs
and disturb the species that inhabit such reefs.

23. Coral Mining
• Corals are often harvested from reefs and are used for several
purposes. Corals are used to make bricks, fill roads, or manufacture
cement.
• They are also sold as souvenirs to tourists.
• These activities deplete the coral reefs of their main building blocks
and lead to the degradation of the coral reef.

24. Toxic Chemicals
• Untreated effluents containing harmful chemicals that are released
into the water bodies from several industries pose a serious threat to
coral reefs.
• Chemicals like methylparaben and oxybenzone that are used in most
sunscreens.
• Metals, such as mercury and lead, and organic chemicals, such as
polychlorobiphenyls (PCBs), oxybenzone and dioxin, are suspected of
affecting coral reproduction, growth rate, feeding, and defensive
responses.

25. Unsustainable Fishing
• 55% of the world’s coral reefs are affected by overfishing.
• When fish populations decline, particularly those that feed on algae,
algae can grow unchecked, eventually smothering corals.
• Other unsustainable fishing practices can physically destroy entire
sections of coral reefs
• e.g.-blast fishing destroys 64 square feet (5.9 square meters) of reef
with a single blast.

26. Stronger Storms
• As sea surface temperatures rise, hurricanes, cyclones, and
typhoons that damage coral reefs become stronger.
• Heavy rainfall from the storms can also erode coastal lands
and bring more polluted runoff into the ocean.

27. Ghost nets
• Ghost nets are silently drifting through the Northwestern Hawaiian
Islands, snagging on coral reefs and entangling wildlife.
• They break, shade, and abrade coral, preventing them from healthy
growth.
• These lost or abandoned fishing nets are a persistent threat that
accumulate over time, but we know little about the damage nets
inflict upon corals.

28. Invasive alien species
• Species that, as a result of human activity, have been moved,
intentionally or unintentionally, into areas where they do not occur
naturally are called “introduced species” or “alien species”.
• In some cases where natural controls such as predators or parasites
of an introduced species are lacking, the species may multiply rapidly,
taking over its new environment, often drastically altering the
ecosystem and out-competing local organisms.
• The damage caused by invasive species can be devastating, through
alteration of ecosystem dynamics, biodiversity loss, reduction of the
resilience of ecosystems, and loss of resources, with environmental,
economic as well as socio-cultural impacts.
• Actually, the threat to global biodiversity from Invasive Alien Species
is the second after habitat destruction.

29. Trash and micro-plastics
• Trash such as plastic bags, bottles, and discarded fishing gear (also
called marine debris) that makes its way into the sea can snag on
corals and block the sunlight needed for photosynthesis, or entangle
and kill reef organisms and break or damage corals.
• Degraded plastics and microplastics (e.g., beads in soap) can be
consumed by coral, fish, sea turtles, and other reef animals, blocking
their digestive tracts and potentially introducing toxics.

30. Rising Sea Levels
• Observations since 1961 show that the average temperature of the
global ocean has increased even at depths of 3000m (IPCC report),
and that the ocean has been absorbing more than 80% of the heat
added to the climate system.
• Such warming causes sea level rise and creates problems for low lying
nations and islands.

31. Threats to coral reefs: climate change

32. Land-Based Pollution
 25% of reefs around the world are affected by agricultural runoff.
 Wastewater on coral reefs takes on many forms—sewage, agricultural
runoff, industrial waste discharge, etc.
 When wastewater enters the marine environment, it brings with it
chemicals and bacteria that are harmful to coral reefs and humans.
 It also brings nutrients, which can spur the growth of algae.
 And if sediment travels into the ocean via runoff, it can block out the
necessary sunlight that corals need to survive.

33. Conservation and Restoration
WHAT CAN WE DO???
Restoration ………….“the process of assisting the recovery of an
ecosystem that has been degraded, damaged, or destroyed” (SER
working group 2004).

34.  Implement best practices for reducing harmful runoff in farming,
grazing, mining, and forestry projects.
 Protect & Restore degraded terrestrial and coastal ecosystems to
reduce runoff and erosion
 Land-based sources of sediment and pollution are managed through
coastal zone planning and enforcement, sewage treatment, and
integrated watershed management to reduce erosion and nutrient
runoff from agriculture.
 Identify new appropriate fisheries management options such as
protected areas or gear restrictions and catch limits.
 Establish protected areas on land to minimize runoff
 Construct fewer ports
 Strengthen existing fisheries management efforts.
 Develop sustainable tourism management plans

35.  Controls on discharge from ships, shipping lanes, and anchoring in
sensitive areas.
 By raising awareness of coral reef goods and services
 Techniques to improve management of reef resources.
 Educate and communicate knowledge to inform communities,
government agencies, donors, and the general
 Conduct scientific research
 Train and build capacity
 Conduct and publicize economic valuation
 Provide support to policy makers and planners

37. How we restore coral reefs?
 Planting nursery grown corals back onto reefs.
 Making sure habitat is suitable for naturals coral growth
 Building coral resilience to threats like climate change.
 Growing and planting healthy corals.
 Removing invasive species.
 Responding to emergencies.
 Improving habitat quality for corals.
 Preventing loss of corals and their habitat.
 Enhancing coral population resilience.
 Improving coral health & survival.
A plan to save coral reef

39. Restoration
methods
Larval
enhancement
Micro-
fragmentation
Coral
gardening
Artificial
reefs
Substratum
stabilisation
Genetic
diversity in
asexual
propagation
Direct
transplantation

40. Method Definition
1. DIRECT TRANSPLANTATION Transplanting coral colonies or fragments without an
intermediate nursery phase
2. CORAL GARDENING Nurseries can be in situ (in the ocean) or ex situ (flow through
aquaria).
3. SUBSTRATE ADDITION
(ARTIFICIAL REEF)
Adding artificial structures for purposes of coral reef
restoration as a substrate for coral recruitment, coral
planting, and/or for fish aggregation
4. SUBSTRATE
MANIPULATION.
Manipulating reef substrates to facilitate recovery
processes
5. LARVAL PROPAGATION Releasing coral larvae at a restoration site, after an
intermediate collection and holding phase, which can
be in the ocean or on land in flow through aquaria.
6. Genetic diversity in
asexual propagation
Acroporids, which are used preferentially in asexual
propagation methods, naturally reproduce asexually through
fragmentation, so the recommended genetic diversity ratio
reflects the proportion of unique genotypes per number of
colonies sampled in a specific stand or thicket. The clonal
processes preferentially used in coral gardening inherently
limits the proliferation of different genotypes and hence
resilience.

41. Generalized coral cover targets and associated restoration actions for
the three consecutive phases of the Mission: Iconic Reefs project.

42. Suite of actions considered to achieve the restoration
objectives for the Mission: Iconic Reefs project.

43. If you live near coral reefs:
 Follow local laws and regulations designed to protect reefs and reef
species.
 If you fish, do it sustainably, avoiding rare species, juveniles, breeding
animals, and spawning aggregations.
 Avoid causing physical damage to reefs with boat anchors, or by
trampling or touching reefs.
 Minimize your indirect impacts on reefs by choosing sustainably
caught seafood and reducing household waste and pollution that
reaches the marine environment.
 Supporting organizations that take care of reefs

44. If you visit coral reefs:
 Choose sustainably managed, eco-conscious tourism providers.
 Dive and snorkel carefully, to avoid physically damaging reefs.
 Tell people if you see them doing something harmful to reefs.
 Visit and make contributions to MPAs to support management
efforts.
 Avoid buying souvenirs made from corals and other marine species.

45. Wherever you are:
 Avoid buying marine species that are threatened or may have been
caught or farmed unsustainably.
 Help to prioritize coral reefs, the environment, and climate change
issues within your government
 Support NGOs that conserve coral reefs and encourage sustainable
development in reef regions.
 Educate through example, showing your family, friends, and peers
why reefs are important to you.
 Reduce your carbon footprint.
 Choose sustainably caught seafood.

46. Protection of coral reefs for sustainable livelihoods
and development
 Don’t fish or boat near a coral reef.
 Don’t litter on the beach or in the ocean.
 Snorkel and scuba dive with care.
 Don’t purchase coral souvenirs.
 Boycott damaging fishing methods.
 Volunteer to support reef science.
 Help organizations dedicated to protecting coral reefs.
 Tell others about coral reefs.
 Reduce pollution in marine habitat.

47.  Improve local marine biomass and biodiversity
 Educate, Raising Awareness and inform tourists about the
preservation of coral ecosystems.
 Protect coastal habitat from erosion and degradation of the marine
environment
 Develop an under water museum mixing art and conservation.
 Go green and travel smart
 Volunteer to clean up our beeches.
 Creation, development and management of marine protected areas,
biosphere reserves, parks and sanctuaries protects multiple
ecosystems.
 Restoration of coral ecosystems.
 Sustainable fisheries.
 Laws need to be strictly enforced.
 Building artificial reefs(in-situ/transplanted).

48. International Organizations and Programs
for Conservation and Restoration of Coral Reefs
 ICRI-International Coral Reef Initiative
 GCRMN-Global Coral Reef Monitoring Network
 CBD-Convention on Biological Diversity
 UNESCO’s Intergovernmental oceanographic Commission
 World Heritage Marine Programme
 UNCLOS-UN Convention on the Law of the Sea
 MARPOL-International Convention on the Prevention of Pollution
 NOAA Coral Reef Conservation Program
 CITES- convention on international trade in endangered species
 UNEP- United Nation Environment Program
 WWF- World Wildlife Fund
 NCRI- National coral reef conservation program
 GCRA- Global Coral Reef Alliance

49. MARINE NATIONAL PARKS & SANCTUARIES FOR
CONSERVATION OF CORAL REEFS IN INDIA
 Gulf of Mannar Marine National Park, Tamilnadu
117 species from 14 families and 40 genus, almost fringing reefs
 Gulf of Kutch Marine National Park, Gujarat
44 sp. of Hard corals and 10 sp. of soft corals
 Mahatma Gandhi Marine National Park, Andaman
fringing reefs
 Malwan Marine Sanctuary, MH
 Sundarbans, West Bengal
 Andaman & Nicobar Island
fringing reefs, barrier reef
 Lakshadweep Islands
Oceanic Atolls

50. Conclusion
Coral reefs are vital to coastal communities and nations
around the world.
The threats to the world’s coral reefs, however, are serious
and growing.
In the face of such pressures, it is critical that we focus on
practical, immediate responses, such as those highlighted
above, to reduce and to reverse these threats.
Action now could ensure that coral reefs remain, and that
they continue to provide food, livelihoods, and inspiration
to hundreds of millions of people now, and for generations
into the future.

51. References
• U.S. Commission on Ocean Policy. 2004. An ocean blueprint for the 21st century final report.
Washington, DC: U.S. Commission on Ocean Policy.
• Coastline protected by reefs was calculated at WRI from coastline data from the National
Geospatial Intelligence Agency, World Vector Shoreline, 2004; and coral reef data from the
Institute for Marine Remote Sensing, University of South Florida (IMaRS/USF), Institut de
Recherche pour le Développement (IRD/UR), UNEP-WCMC, The World Fish Center, and WRI, 2011.
• C. M. Roberts. 1995. “Effects of Fishing on the Ecosystem Structure of Coral Reefs.” Conservation
Biology 9 (5): 988–995
• L. Cao, K. Caldeira, and A. K. Jain. 2007. “Effects of carbon dioxide and climate change on ocean
acidification and carbonate mineral saturation.” Geophysical Research Letters 34 (5):5607.
• B. Riegl, A. Bruckner, S. L. Coles, P. Renaud, and R. E. Dodge. 2009. “Coral reefs: threats and
conservation in an era of global change.” Annals of the New York Academy of Sciences 1162 (The
Year in Ecology and Conservation Biology 2009):136–186.
• Lauretta Burke et al. Reefs at Risk Revisited Summary for Decision Makers. World resources
institutes Washington DC.
• Andrello, M., Darling, E. S., Wenger, A., Suárez‐Castro, A. F., Gelfand, S., & Ahmadia, G. N. (2021). A
global map of human pressures on tropical coral reefs. Conservation Letters, e12858.
• The Nature Conservancy’s rallying call in the 2018 International Year of the Reef:“Keep Calm and
Coral On”
• CORAL REEF RESTORATION. A guide to coral restoration methods

52. THANK YOU