Coral reefs are central to the biology of our planet;
in terms of biodiversity, they are the most rich,
complex, and productive marine ecosystem on
Earth. It has been estimated that over 90% of the
species inhabiting coral reefs have yet to be
described. Therefore, it is not surprising that the
organisms that constitute these ecosystems
produce a great variety of molecules with unique
structural characteristics that exhibit numerous
biological activities, and are considered a rich
source of novel bioactive agents with great
pharmaceutical and biotechnological potential.
Despite occupying only 0.1% of the ocean, coral
reefs play a critical role in marine ecology, and
in human sustainability, they are invaluable
from a variety of perspectives. They are home
to more than a quarter of all the species that
inhabit the ocean, provide coastal protection,
and support more than 10 millions of people
living on tropical coasts. Economic goods and
ecosystem services of coral reefs are worth
more than US $20 trillion annually.
Despite all of these, in the past few decades,
they have suffered a severe decline due to a
variety of natural and anthropogenic
disturbances. Unfortunately, coral reefs are
extremely susceptible to the stress related to
greenhouse gas emissions, particularly ocean
warming and acidification, which provoke
disturbances that can seriously affect and
break down the homeostatic capacity of coral
reefs to overcome stressors.
One of these disturbances is the event called
“bleaching,” in which the tissues of corals and
hydrocorals
lose
their
photosynthetic
endosymbiotic
zooxanthellae
or
their
pigments, which exposes the white
exoskeleton of calcium carbonate.
Bleaching is also responsible for other declines
in reef health, such as the increase in coral
diseases, declines in reef calcification, the
breakdown of reef framework by bioeroders,
and the loss of critical habitat for associated reef
organisms. Climate models predict that, if
CO2emissions continue to rise at the current
rate, bleaching events will increase in frequency
and severity, threatening the survival of coral
reefs. Actually, it has been projected that 90%
of coral reefs around the world will be at risk if
bleaching events occur annually.
In the Philippines, coral reefs have suffered
three major global bleaching events in recent
decades: in 1998, 2010 and 2016. And for the
most recent, 2020 is really that year. From a
pandemic to murder hornets to an asteroid
that came relatively close to us, it's like there's
a new thing that threatens all of humanity each
week. The latest thing we have to be alarmed
about, or rather, we should have been alarmed
about from the start is a coral bleaching event.
And as long as water temperatures keep rising,
more bleaching will occur.
For millions of Filipinos who are heavily
dependent on coral reefs for their food,
livelihoods, and coastal protection, the
consequences of coral bleaching aren’t just
tied to their present, but also their future.
The Philippine Coral Bleaching Watch,
powered by the University of the Philippines
Marine Science Institute and the Philippine
Department of Environment and Natural
Resources, just gave an update for an alert
level 2 in parts of Batangas, including
Tayabas Bay, parts of Mindoro in Tablas
Strait, and Guimaras Strait in Western
Visayas.
According to PCBW coordinator, Miladel
Quibilan “We are encouraging people to not
just submit coral bleaching reports, but reports
of coral reefs in the country that are still
thriving despite exposure to repeated coral
bleaching events in the past,” end of quote.
Once resilient reefs are identified, the strategy
to protect reefs can be more streamlined. In
the future, these “reefs of hope” may be
reproduced once the climate becomes more
stable.
General mitigation, repair and adaptation
strategies may be considered too, but they
tend to be more costly and, in some cases, not
as effective in the long run. Some coral reef
scientists are also trying to come up with a
“super coral,” one that can withstand changing
ocean conditions, but there is no guarantee
that there will be results any time soon. And if
can afford and have the capacity, they will try
to implement all of these strategies at the same
time to get the most impact.
Saving reefs will not be possible without
a collaborative effort. Let’s help in
looking for healthy, non-bleaching reefs.
Continue to be the eyes underwater, be
the lookout if your reef areas are
bleaching or not bleaching. We all need
to monitor reefs that are resilient to heat
stress, and reefs that are able to recover.
Save Marine Ecosystem, Save the Coral
Reefs.
https://www.esquiremag.ph/culture/lifestyle/philippine-coralbleaching-watch-june-2020-a00297-20200629
https://news.mongabay.com/2020/07/app-harnesses-citizen-power-tokeep-tabs-on-philippines-coral-reefs/
https://www.intechopen.com/books/corals-in-a-changing-world/coralreef-bleaching-an-ecological-and-biological-overview