[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,
best,
Carin
--
Dr. Carin Jantzen
Marine Ecologist & Author
SECORE Media & Public Relations
More information about the Coral-List
mailing list