[Coral-List] Kanton Atoll, Phoenix Islands

[David Obura]

Dear Phil,

Corals in the Phoenix Islands started early stages of bleaching in July 2002
just as we were leaving the islands after a 3-week stay there. We noted this
in a small number of the near-100% cover stands of staghorn/plating Acropora
in Kanton lagoon (the same community you mention), and on some outer reef
corals. In the months following our departure, the area was under an extreme
hotspot for several months, which sat in place, rather than migrating
eastwards across the Pacific as a similar hotspot did in the 1997-98 El
Niño. Good news for the rest of the world¹s corals, but bad for the Phoenix
Islands!! The NOAA maps of course showed this very clearly and raised the
alarm very strongly for our expedition group, and show 15+ degree heating
weeks from mid-September, to the far right of the colours I can distinguish
on the legends.

Unfortunately, though we tried hard from August to September of 2002 to get
reports back from a Settlement Scheme on Orona Island, and the
administrative population on Kanton, we were not successful in raising any
communication. There¹s no doubt in my mind that the mortality you report was
due to that hotspot ­ the signs are all there ­ consistency of mortality,
especially in Acropora, the degree of coralline algae cover now, and lack of
impact to the fish populations (which are probably supported heavily by
upwelling of the Equatorial Undercurrent); and the near-total lack of any
local man-made threats such as fishing, pollution, etc. In fact, I¹m a
little surprised that mortality had not been even higher on the outer reefs,
and again, this is probably attributable to upwelling and low residence time
of waters in the shallows around the islands.

We will be happy to work on linking up datasets from our pre-bleaching
surveys of 2000 and 2002. Our summary reports are available from the New
England Aquarium (www.neaq.org), either from the website directly or
physical copies could be provided by the Global Marine Programmes office
there. 

As a final FYI and might be a matter of interest to others on the list, we
(led by the Global Marine Programmes of the New England Aquarium) are
currently in the Implementation Phase (2005-06) of setting up a
comprehensive Management Plan for the islands, based on an endowment fund
incorporating a Œreverse fishing license¹ concept ­ so that the Kiribati
government receives an annual income from the islands that pays for their
management, and provides some benefits to the heavily populations Gilbert
Islands and growing populations in the Line Islands. The Global Conservation
Fund at Conservation International is taking a keen interest in developing
this idea and funding the Implementation Phase, and the project will
integrate with other growing initiatives such as the World Heritage Central
Pacific project, and the AFD-CRISP programme being funded by France in the
Central Pacific.

The news from the Heraclitus of bleaching in the Phoenix Islands is of
course devastating ­ these were the ONLY pristine islands that I had ever
seen. However it is a sadly all-too common story now. It will be a challenge
for us to incorporate this in a meaningful way into the conservation plan
and estimating the value of the islands, to provide a plan that provides
benefits to Kiribati. On the science side, the big question of course is
recovery and future prospects. Coralline algal cover as good as shown in
your photographs is rare, and regrowth from surviving corals and new
recruits might be rapid as a consequence. The untouched herbivore
populations probably have a large role to play in maintaining the coralline
cover. The big question is larval supply, and if the isolation of the
islands will constrain recruitment rates, or viability of some coral
species, or overall recovery.

All best,

David Obura
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