[Coral-List] coral reefs in the face of climate change

Carin Jantzen carin.jantzen at gmx.net
Wed May 4 06:28:54 EDT 2016

Dear all,

With interest I have followed the discussions on what we can do to help 
dying coral reefs in the face of climate change, especially in context 
of the most severe and unsettling third global bleaching event and the 
subsequent mass die-off of corals and whole reefs.

We probably all agree that we, most importantly, need to act against the 
ongoing climate change, meaning to reduce our Carbon-dioxide emissions 
to prevent conditions from getting unbearable for all of us. What we are 
facing now is just the beginning. We need to act as citizens, humans, 
and as a species that like to persist on this earth – best together with 
most of the other species on earth as well; not going into detail here 
about biodiversity, natural resources, changing conditions in 
agriculture, climate refugees or even wars...

People wish to do something, to directly help the corals right now, but 
I think any attempt that works only quite locally like shading (wse 
method) or extracting CO2 from the water are only a drop in the bucket. 
If one, for instance, has managed to shade some corals and they really 
survived – the next bleaching will wipe them out (or the one after 
that). Water temperatures will continue to rise and bleaching may become 
more frequent in the future.

Apart from the most urgent task to act against climate change, we need 
to assist natural evolution to help coral reefs to go through the next 
(tough) decades. There may be three kinds of action that could make 
sense – at least to my limited understanding. However, I am aware that 
they are not easy tasks, still, I think our joint efforts should work in 
that direction.


    Reduce other stresses than climate change to give surviving corals
    the opportunity to recover.


    Protect corals and reefs that are less susceptible to bleaching:
    Reef areas that are, for instance, exposed to up-welling and where
    bleaching is therefore moderated, may be suitable MPAs for future
    coral havens. Reefs that feature certain coral genotypes or species
    that are less effected by bleaching may be given special status.


    Restore coral reefs by using sexual coral reproduction in order to
    promote genetic diversity, to give certain genotypes the chance to
    do better than their dying parents, and by using certain genotypes
    or species that are more likely to survive, i.e. are less
    susceptible to bleaching (or pollution etc....). This approach may
    only assist coral reefs to recover or to rehabilitate to some
    degree; instead of growing a new reef like it was before, it would -
    in the best case - maintain or restore ecological functions of a
    reef. The right place to start such an effort is most critical too.
    Best chances may be in a MPA, where natural recruitment is next to
    non-existing, but apart from that, conditions are well managed
    (regarding overfishing, pollution and so on...). And we need to work
    on larger scales too.

To which degree we want to interfere with natural evolution and to 
choose certain genotypes is maybe something that could be discussed here 
on the coral list. It is tempting to just say 'those corals survived, 
use them to make a new reef'. We still do not know enough about the 
functioning of the coral reef as a system to know what we would be 
doing. Additionally, there are many examples from the past that show 
that human fiddling with evolution has not always (rarely?) turned out 
well... On the other hand, time presses and we may not have many choices 
(and chances)...

Corals reefs are dying at an alarming rate. Their conditions will not 
get better, facing the ongoing climate change, but rather worse. We need 
to be very forthright about that, and think and act accordingly.

This is my personal opinion,




Dr. Carin Jantzen
Marine Ecologist & Author
SECORE Media & Public Relations

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