[Coral-List] Reliable coral reef stats

Gregor Hodgson gregorh at reefcheck.org
Sun Sep 15 18:09:21 EDT 2013

Since 1997, Reef Check has carried out a global monitoring program of coral
reefs using a standardized method based on about 30 indicators including
living coral and recently killed coral, bleached and diseased coral. Prior
to 2005, Reef Check teams were trained and led by Masters or PhD level
scientists who were responsible for field level Q & A. Since 2005, all Reef
Check data has been collected by individuals who have been through a formal
training program, tested and certified to collect data.  In fact about 75%
of the data has always been collected by research scientists because Reef
Check methods have been adopted by many countries and research institutes as
part of their core monitoring program. Independent researchers such as John
Bruno et al., have used the database for local and regional meta analyses.
The database is available to any researcher. Our WRAS online coral reef
database has been taken offline to transition it from a GIS to a Google
Earth platform, and to merge it with our California NED online rocky reef
database. http://ned.reefcheck.org/ An analysis of the 15-year coral reef
dataset is due out in 2014. For a list of peer reviewed and other technical
publications based on or related to Reef Check data please see:

Reef Check offers regular training programs throughout the world using our
local coordinators. If you think it is important to track coral reefs during
the next 20 years of global warming, please contact rcinfo at reefcheck.org to
arrange a training or if you would like to help coordinate surveys in a
country where we do not have a coordinator.

I am noticing two problems when researchers try to compare baselines now
with pre-1980s data:
1. there is a shifting baseline in new cohorts of coral reef researchers who
have a hard time understanding what reefs actually were like 40 years ago,
but typically have not read the old descriptive literature from pre-1970s
such as Saville-Kent that provide exceedingly detailed descriptions of what
the shallow reefs were like;
2. a problem with meta-analyses that do not  take into account the fact that
in 2013, there are no "zero coral cover" data from former reefs or zones of
reefs that are no longer reefs because they experienced 100% die off and so
researchers no longer monitor them. Some former reef zones that were
populated by Acropora palmata can still be seen, as the dead skeletons are
still in place, but those formerly populated by the more fragile A.
cervicornis are often simply gone. This means that the current regional and
global coral cover estimates are probably underestimating the decline as
researchers no longer include reefs that died and have not recovered.

Gregor Hodgson, PhD
Executive Director
Reef Check Foundation
PO Box 1057 (mail)
17575 Pacific Coast Highway (overnight)
Pacific Palisades, CA 90272 USA
T: +1 310-230-2371 or 2360
Gregorh at reefcheck.org
Skype: gregorh001

More information about the Coral-List mailing list