9/21/09

A fully regenerated reef on Enderbury Island

This entry is written by Les Kaufman, Professor of Biology at Boston University.

We reached Enderbury Island early this morning (September 20). First rose the sun; and then, the birds. It is a low island, basically a doughnut surrounding a guano lake of sorts. A landing party that went to explore the island in the early morning, returned to report that a rat eradication was badly needed; the birds were struggling (more about the rat problem on the Phoenix Islands here). Tukabu and Greg had killed a rat during their survey of the island with a well-aimed rock and then photographed it to document the species. They also found a bottlenose dolphin skull and lots of fishing floats, including one made of glass.


A nesting bird on the Phoenix Islands (Photo: G. Stone)

Meanwhile, others were underwater, in heaven. The moment we dropped into the sea just off NAI'A's bow in the lee of Enderbury, our mouths fell agape and stayed that way for the entire dive and a good while afterwards. A fully regenerated reef! Over 90% coral cover, sharks, dogtooth tuna and the joy of having a good reason to be careful about neutral bouyancy. The transect methodology was the same tired old routine, but we felt like whistling the entire time.




(Photo: Jim Stringer)

We hovered over fields upon fields of yellow scrolls and rolling sheets, broken here and there by massive colonies of other species. And therein lies the clue to the fact that all this glory was fresh in time and not some prevailing condition: why is one species of coral (Montipora aquatuberculata as it happens) so dominant in a system with up to two hundred coral species in the pool? David went back to the 2005 data. This reef had bleached pretty hard, like so many others in PIPA. But clearly, this reef had come back... most of the way.


(Photo: Jim Stringer)

In most respects it was a healed reef: total coral cover, the fishes, the abundance of coralline and lack of soft fleshy algae. Technically, though, it was not fully recovered until the native species diversity was restored. In tropical forests, regenerating lands can assume nearly the full ecological function set of a rainforest in about 100 years, but they are not mature until the diversity is fully restored. For the forest, this can take several centuries. For an equatorial mid-Pacific coral reef, who knows? Our other two data dives were also pleasant and went quickly. Plenty of sharks--though curiously small ones comprised much of the lot. Lots of Napoleon wrasse, including some really big ones, and lots of bohar snapper. On the last dive, a swarm of grey reef and white-tip reef sharks right along the transect line--a true delight.


(Photo: Jim Stringer)

I noticed that the schools of juveniles of a common wrasse contained a mimic blenny in their midst--fascinating, but vexing because now we don't know how long we were missing it on our censuses! Today we also discovered a (to us) new color form for the common Foster's hawkfish: grey with a flaming red back. After three dives, I took a break. Up on the top deck with Tuake, we talked fishing, Kiribati conservation and careers, as I kept an eye on the birds returning to their nests. Grey noddy--a life bird for me!


Birds of the Phoenix Islands (Photo: Greg Stone)

Later, after dinner, stars, clouds, a near-new moon, moving to new for the approaching day of reckoning. If I've yet to expunge my sins, at the least I've been cleansed of despair.

-Les Kaufman

3 comments:

  1. Wow!
    A really powerful post... thanks for writing it

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  2. Great update Les! Can't wait to catch up when you get back!

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  3. Hey Les, nice post. Where's the photo of the mangled rat that's what I want to see. Maybe the bleaching of the corals is similar to the clear cutting of the rainforest. You will get pioneering species but eventually we need some thoughtful intervention to help nature move forward. Here on the land I can think of a couple of examples where local indigenous knowledge has been used to usher regeneration/restoration intiatives. Could there be something like this done with corals?

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