[Coral-List] FIELD OF GIANTS

David Blakeway fathom5marineresearch at gmail.com
Fri Sep 17 11:45:53 UTC 2021


That would be an unforgettable dive.
There's s super photo of the colony here, from the article:
https://www.nature.com/articles/s41598-020-77776-7/figures/3

On Fri, Sep 17, 2021 at 10:24 AM Charles Birkeland via Coral-List <
coral-list at coral.aoml.noaa.gov> wrote:

> FIELD OF THE GIANTS
>
> Findings on the GBR usually get a lot of notice. For example, the
> description in a recent Nature Scientific Reports (online 19 August 2021)
> of the largest massive *Porites* colony on the GBR (5.3 m high, 10.4 m
> wide, 31 m in circumference and between 421 and 438 years old) received a
> lot of attention. A few months earlier (same journal, online 7 December
> 2020), a similar article (I was *not* an author) described a scattered
> group of seven very large massive *Porites* cf. *lutea* at the island of
> Ta’u, American Samoa (the two largest were 8 and 7 m high, 22.4 m wide
> (over twice the diameter of the GBR specimen) and 17 m wide (diameter),
> circumference 69.4 and 41.0, and I heard that growth rings from a core
> indicated the second largest one to be 540 years old), but this article was
> hardly noticed. If we assume the *Porites* colonies were hemispherical,
> which I believe is quite reasonable, then the volume of the GBR colony
> 2πr3/3
> is 294 m3. The volumes of the two largest in the Field of the Giants were
> 1286 and 2942 m3, or were 4.4 and 10 times the mass of the largest on the
> GBR. For surface area, 2πr2, the areas of the *Porites* colonies were 170
> m2
> (GBR) and 454 and 788 m2 for the two at Ta’u. The two at Ta’u were 2.7 and
> 4.6 times the area of the largest on the GBR. Twice the diameter is not
> particularly impressive, but this indicates 4.6 times the surface area and
> 10 times the mass. American Samoa is thought of as a tough and challenging
> environment for corals with major crown-of-thorns outbreaks, numerous
> cyclones, mass bleaching events, occasional extreme low tides, a tsunami,
> and with sea level rising five times as fast as the global average because
> the islands are sinking relatively (geologically) fast (Han et al. 2019 JGR
> Solid Earth 124: 4142-4156). Despite these harsh conditions and frequent
> damage to coral communities, the corals of American Samoa are remarkably
> resilient and the dynamic system deserves attention. It is good to keep a
> log of all massive *Porites *colonies greater than 10 m in diameter, and
> around the world, there are probably a number of colonies larger than the
> 22.4 m diameter colony at Ta’u; but no matter how many are larger, the
> Field of the Giants is still a marvelous sight in American Samoa.
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