Coral Growth Rates (was Re: Four Rivers Revisited)

Arthur V. Chadwick (chadwicka@swau.edu)
Wed, 12 May 1999 19:05:37 -0700

At 09:19 AM 5/12/99 -0400, Dick wrote:

So how deep did they drill at Eniwetok? From the top of the reef, they
drilled through 4,610 feet of coral before reaching the volcanic sea mount
at the bottom. If the coral started growing at the day of creation and
forged ahead nonstop, for it to reach almost a mile in height would take
165,960 years! But how old is the volcano it rests on? Plus, there were
times in the past when the coral was above water as evidenced by
concentrations of pollen in the zones of 2,440 feet to 2,510, 820 to 880
feet and 670 to 680 feet. How long did Eniwetok tarry above sea level at
least three times before it again was submerged and could start growing
again? How many times was the coral too deep to grow? etc.

Ariel Roth , who spent his professional career studying coral reef growth
has written the following:

On a quiet moonlit night in the year 1890 the British-Indian liner Quetta
traveled
through the Torres Strait near Thursday Island, north of Australia. Located at
the northern end of the Great Barrier Reef, it is the world's most widespread
coral reef complex. The ship suddenly hit a reef pinnacle that ripped through
most of its hull, and sank within three minutes. Nearly half of the ship's 293
passengers perished. The strait had been carefully charted between 1802 and
1860, and the crew expected no reef where the ship foundered. Some have
wondered if possibly a coral reef could have grown rapidly enough between the
time of sounding and 1890 to cause the tragedy.1

Coral reefs result from the activity of a variety of organisms that remove
lime
(calcium carbonate) dissolved in seawater and slowly create the largest
structures on earth made by living organisms. Mollusks, foraminifera, and
bryozoa
can provide substantial amounts of minerals for reef growth. However,
biologists
consider coral and coralline algae to be the most important contributors.

The rate of coral reef growth is of considerable interest not only because
reefs
are potential navigational hazards but also because of questions about the
amount
of time required to build them. Some wonder whether such huge structures could
form in a few thousand years, as implied by the biblical model.

The enormous Great Barrier Reef of Australia does not appear to pose a very
serious time problem for Scripture. While it is more than 2,000 kilometers
long
and up to 320 kilometers offshore, drilling operations down through the
reef have
encountered quartz sand (a nonreef type of sediment) at less than 250 meters2
indicating that it is a shallow structure not requiring a vast amount of
time for
development. On the other hand, drilling operations on Enewetak (Eniwetok)
Atoll
in the Western Pacific have penetrated 1,405 meters of apparent reef material
before reaching a volcanic (basalt) rock base.3 The rates of growth assumed by
most investigators would dictate that it would take at least scores of
thousands
to hundreds of thousands of years to form a reef this thick. Criticizing
the biblical
model, one author points out that the Eniwetok reef would have to grow at the
rate of 140 millimeters per year to have formed in less than 10,000 years. He
states: "Such rates have been shown to be quite impossible."4

Researchers face many problems in determining how rapidly reefs grow. The fact
that some estimates are more than 500 times faster than others (Table 1)
indicates that we know extremely little about such complex and delicate
ecological systems. The sparse distribution of coral in some studies
reflects less-
than-ideal reef conditions. The best growth rates seem to take place a little
below the surface of the ocean.5 Reefs cannot grow above sea level, and re-
searchers sometimes use ancient reef surfaces to determine past sea levels.
Since sea level limits the growth of reefs, estimates of growth near the
surface
of the ocean may be strongly influenced by growth-limiting circumstances. Low
tides can kill the reef-forming coral by exposing them too long to the air.
Silting
and pollution from land can also be detrimental. Furthermore, a number of
present-day reefs are now dying or dead.6 Less-polluted conditions when earth
was not so populated could have favored more rapid growth of the delicate
organisms that build reefs.

One must also remember that coral reef growth ceases below a certain depth
because of lack of light. Therefore, scientists assume that the volcanic
base of
Eniwetok Atoll, now 1,405 meters below sea level, would have been near sea
level
when coral growth began on its surface. The base gradually sub- sided, and
coral
growth kept up with this.

Some of my graduate students and I have studied reef-building organisms of
Eniwetok and several other reef localities to determine how various
environmental
factors affect growth. A moderate rise in temperature of a few degrees favors
more rapid growth, while ultraviolet light at the ocean surface inhibits
growth.7
These and other factors can significantly affect rates of reef growth. While
some of the hard "brain"-shaped coral and coralline algae grow slowly, the
branching forms develop rapidly. A dense concentration of healthy
branching coral growing at optimal rates (second part of Table 1) could create
rapid reef growth. Many corals frequently form branches above each other,
compounding production rates. The potential is impressive, 10 branches each
growing at the rate of 100 millimeters per year and subdividing into three
branches each year would result in a total of 59 kilometers of single
branches in
10 years.8

A number of investigators have studied rates of coral and coral reef growth.
Some estimates appear in Table 1. The top section, entitled "Rates of Reef
Growth," derives from observations of reefs as a whole, while the section
entitled "Maximum Rate of Coral Reef Frame Builders" represents the fastest
rate of growth of those corals that could provide a physical framework for the
reef. This framework would also offer protection for other smaller
reef-building
organisms as well as serving for the entrapment of water-transported
sediments. Note that the fastest rates for reefs9 and for framebuilders10 do
allow for the growth of the Eniwetok reef, which has a thickness of 1,405
meters,
in less than 3,400 years. These fastest rates for reefs are based on
soundings,
which are the most direct and simple measurements and are probably more
reliable than the less-direct methods that give slower growth rates. Such data
indicate that the rate of coral reef growth does not present as great a
challenge
to the biblical concept of creation a few thousand years ago as is sometimes
claimed.

Estimates of Rates of Reef Growth
METHOD OF
EVALUATION RATE (MM/YR) YRS TO GROW A 1,400-M REEF AUTHOR(S)
(DATE)
Carbon-14 dating 6 -15 233,000 -93,300
Adey (1978)
Coral growth and
potential estimate 0.9 -74 1,550,000 -18,900
Chave et al. (1972)
Carbon-14 dating 1 ->20 1,400,000 -<70,00 `
Davies and Hopley (1983)
Growth rings (and
maximum) 0.7 (3.3) 2,000,000 -424,000
Hubbard et al. (1990)
Potential estimate 80 17,500
Odum and Odum (1955)
Soundings 280 5,000
Sewell (1935)
CO2 system 2 -5 700,000 -280,000
Smith and Kinsey (1976)
CO2 system 0.8 -1.1 1,750,000 -1,270,000
Smith and Harrison (1977)
Soundings 414 3,380
Verstelle (1932)

Maximum growth Rates of Coral Reef Frame builders
SPECIES RATE(MM/YR) YRS TO GROW 1,400-M REEF
AUTHOR(S) (DATE)
Antipathes sp 143 9,790
Earle (1976)
Acropora palmata 99 14,100
Gladfelter et al. (1978)
Acropora cervicornis 120 11,700
Gladfelter (1984)
Acropora cervicomis 264 -432 5,300 -3,240
Lewis et al. (1968)
Acropora cervicomis 100 14,000
Shinn (1976)
Acropora pucchra 226 6,190
Tamura and Hada (1932)


* References for the table "Estimates of Rates of Reef Growth" are: (a)
Adey WH. 1978. Coral feet morphogenesis: a multidimensional model. Science
202:831-837; (b) Chave KE, Smith SV, Roy KJ. 1972. Carbonate production by
coral reefs. Marine Geology 12:123-140; (c) Davies PJ, Hopley D. 1983.
Growth fabrics and growth rates of Holocene reefs in the Great Barrier
Reef. BMR Journal of Australian Geology and Geophysics 8:237-251; (d)
Hubbard, Miller, and Scaturo (note 17); (e) Odum HT, Odum EP. 1955. Tropic
structure and productivity of a windward coral reef community on Eniwetok
Atoll. Ecological Monographs 25(3):291 -320; (f) Sewell RBS. 1935. Studies
on coral and coral formations in Indian waters. Geographic and
oceanographic research in Indian waters, No. 8. Memoirs of the Asiatic
Society of Bengal 9:461-539; (g) Smith SV, Kinsey DW. 1976. Calcium
carbonate production, coral reef growth, and sea level change. Science
4:937-939; (h) Smith SV, Harrison IT. 1977. Calcium carbonate production of
the Mare Incognitum, the upper windward reef slope, at Eniwetok Atoll.
Science 197:556-559; (i) Verstelle (note 21). References for the section
entitled "Maximum Growth Rate of Coral Reef Frame Builders" are: (j) Earle
SA. 1976. Life springs from death in Truk Lagoon. National Geographic
149(5):578-613; (k) Gladfelter EH, Monahan RK, Gladfelter WB. 1978. Growth
rates of five reef-building corals in the northeastern Caribbean. Bulletin
of Marine Science 28:728-734; (I) Gladfelter EH. 1984. Skeletal development
in Acropora cervicornis. III. A comparison of monthly rates of linear
extension and calcium carbonate accretion measured over a year. Cora] Reefs
3:51-57; (m) Lewis, Axelsen, Goodbody, Page, and Chislett (note 22b); (n)
Shinn (note 20); (o) Tamura T, Hada Y. 1932. Growth rate of reef-building
corals, inhabiting in the South Sea Island. Scientific Report of the
T˘hoku Imperial University 7(4):433-455. The calculations for their
research were reported by: Buddemeier and Kinzie (note 22a).

1. Ladd HS. 1961. Reef building. Science 134:703-715.

2. (a) Flood PG. 1984. A geological guide to the northern Great Barrier
Reef.
Australasian Sedimentologists Group Field Guide Series, No. 1. Sydney:
Geological Society of Australia; (b) Stoddart DR. 1969. Ecology and
morphology of recent coral reefs. Biological Reviews 44:433-498.

3. Ladd HS, Schlanger SO. 1960. Drilling operations on Eniwetok Atoll:
Bikini
and nearby atolls, Marshall Islands. U.S. Geological Survey Professional
Paper 260:863-905.

4. Hayward A. 1985. Creation and evolution: the facts and the fallacies.
London: Triangle (SPCK), p. 85.

5. This has been noted by several investigators, e.g.: Hubbard DK,
Miller Al,
5caturo D. 1990. Production and cycling of calcium carbonate in a
shelf-edge
reef system (St. Croix, U.S. Virgin Islands): applications to the
nature of
reef systems in the fossil record. Journal of Sedimentary Petrology
60:335-360.

6. For some reports, see: (a) Anonymous. 1994. Coral bleaching threatens
oceans, life. EOS, Transactions, American Geophysical Union
75(13):145-147;
(b) Charles D. 1992. Mystery of Florida's dying coral. New Scientist
133 (11
January):12; (c) Peters EC, McCarty HB. 1996. Carbonate crisis? Geotimes
41 (4):20-23; (d) Zorpette G. 1995. More coral trouble. Scientific
American
273(4):36, 37.

7. (a) Clausen CD, Roth AA. 1975a. Estimation of coral growth rates from
laboratory 45C-incor-poration rates. Marine Biology 33:85-91; (b) Clausen
CD, Roth AA. 1975b. Effect of temperature and temperature adaptation on
calcification rate in the hermatypic coral Pocillopora damicornis. Marine
Biology 33:93-100; (c) Roth AA. 1974. Factors affecting light as an
agent for
carbonate production by coral. Geological Society of America Abstracts
With
Programs 6(7):932; (d) Roth AA, Clausen CD, Yahiku PY, Clausen VE, Cox
WW. 1982. Some effects of light on coral growth. Pacific Science 36:65-81;
(e) Smith AD, Roth AA. 1979. Effect of carbon dioxide concentration on
calcification in the red coralline alga Bossiella orbigniana. Marine
Biology
52:217-225.

8. Shinn EA. 1976. Coral reef recovery in Florida and the Persian Gulf.
Environmental Geology 1:241-254.

9. Verstelle JTh. 1921. The growth rate at various depths of coral
reefs in
the Dutch East Indian Archipelago. Treubia 14:117-126.

10. (a) Buddemeier RW, Kinzie RA, Ill. 1976. Coral growth. Oceanography
and
Marine Biology: An Annual Review 14:183-225; (b) Lewis lB, Axelsen F,
Goodbody I, Page C, Chislett G. 1968. Comparative growth rates of some
reef corals in the Caribbean. Marine Science Manuscript Report 10.
Montreal: Marine Sciences Centre, McGill University.

Art
http://geology.swau.edu