[Coral-List] Fwd: Reply to Charles Birkeland
eshinn at marine.usf.edu
Tue Aug 22 10:01:07 EDT 2006
>Dear Chuck, Thanks for responding to my observations about "crude"
>oil and corals. I recall from my 1974 visit to Goleta Point where
>you had conducted the study that there were also test panels coated
>with various refined oils. This is after the spill you mentioned.
>Were these test panels part of the study you were conducting? The
>treated panels were placed on the reef just off the laboratory and
>they had a Braille-like system on them to allow recognition because
>during the monsoon season the water on that reef looks like coffee
>with cream. Fortunately, I visited during the dry season but was
>still amazed that corals, especially Acropora could survive there.
>As I remember, visibility during the dry season (when we were there)
>was no more than 30 ft yet the full complement of Atlantic corals
>were present. Ian MacIntyre and Peter Glynn were just finishing up
>the core drilling that demonstrated how the reef, and reef flat, had
>been constructed by A. palmata over the past few thousand years.
> This classic study, based on a transect of numerous cores
>demonstrated that A. palmata had grown to the surface and had
>accreted seaward and produced a broad reef several meters thick in
>spite of such poor water quality. Yes, Acropora was much more hardy
>before the 1980s.
> As I pointed out in my note to the coral list, crude oil is
>less toxic than refined oils such as bunker C (which will sink) and
>diesel oil that floats and is more water-soluble is even more toxic.
>Considering water conditions at Goleta Point and the greater
>toxicity of the oils tested, it is amazing that your corals
>survived even though their growth rate was reduced. (They were still
>living after 61 days! How long did they live?)
> Also, as I stated, I do not know the ultimate fate of the coral
>I treated and would not be surprised if their growth rate had been
>reduced. I emphasize again that crude oil, the kind most often
>spilled during transoceanic shipment, (or from an offshore blowouts)
>floats and is less toxic than refined products, To my knowledge
>coral bioassays have yet to be conducted using crude oil and I wager
>that such studies will not be attempted. Gene
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