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Poorly cemented coral reefs of the eastern tropical Pacific: Possible insights into reef development in a high-CO2 world

  1. Derek P. Manzello * , † , ‡ ,
  2. Joan A. Kleypas § ,
  3. David A. Budd ,
  4. C. Mark Eakin ‖ ,
  5. Peter W. Glynn † , and
  6. Chris Langdon †
  1. *Cooperative Institute of Marine and Atmospheric Studies,
  2. †Rosenstiel School, Marine Biology and Fisheries, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149;
  3. §Institute for the Study of Society and Environment, National Center for Atmospheric Research, Boulder, CO 80307;
  4. Department of Geological Sciences, University of Colorado, Boulder, CO 80309; and
  5. ‖National Oceanic and Atmospheric Administration, Silver Spring, MD 20910

  1. Edited by David M. Karl, University of Hawaii, Honolulu, HI, and approved May 16, 2008 (received for review December 22, 2007)

  1. Fig. 1.
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    Fig. 1.

    Map showing depressed aragonite Ω (Ωarag) across the ETP in comparison to highly supersaturated waters that influence Caribbean reef sites. Aragonite is the form of CaCO3 secreted by reef-building corals and was the only type of cement found in ETP reefs. Ωarag values were estimated by combining SST, salinity, PO4, and SiO2 from the 2005 World Ocean Atlas (21) with TCO2 and TA values from the 1 × 1° gridded Global Ocean Data Analysis Project data (22).

  2. Fig. 2.
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    Fig. 2.

    Time series of sea temperature. (A) Uva Reef, Panamá [black line, ≈1-m mean low water (MLW)], Saboga Reef, Panamá (dark gray line, ≈1 m MLW), Lee Stocking Island, Bahamas (dashed line, ≈1 m MLW), and Galápagos (light gray line, SST). (B) Uva Reef flat (≈1 m) and 15-m depth (gray line) showing high variance in temperature at depth to illustrate apparent shoaling of shallow thermocline.

  3. Fig. 3.
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    Fig. 3.

    Map of the ETP indicating location of reefs sampled. Numbers denote reefs at (1) Secas Island (7° 57′18′ ′N; 82° 00′45′ ′W), (2) Uva Island (7° 48′48′ ′N; 81° 45′32“W), (3) Saboga Island (8° 37′43′ ′N; 79° 03′26′ ′W), (4) Bartolomé, Santiago Island (0° 17′17′ ′ S; 90° 33′15′ ′W), (5) Sante Fe Island (0° 48′17′ ′S; 90° 2′20′ ′W), (6) Punta Bassa (0° 49′N; 89° 32′W), (7) Pta. Pitt (0° 42′30′ ′S; 89° 15′W), San Cristóbal Island, and (8) Devil's Crown, Floreana Island (1° 12′5′ ′S; 90° 25′23′ ′W).

  4. Fig. 4.
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    Fig. 4.

    Thin-section photomicrographs of cement distributions. All images are at the same magnification. (A) Abundant cementation in the intraskeletal cavities of a coral from Lee Stocking Island, Bahamas with arrows pointing to examples of aragonite cement crystals. (B) Example of most heavily cemented ETP sample from Uva Reef, Panamá. Note that even when present, the thickness, continuity, and size of the aragonite crystals are less than the cements at Lee Stocking Island (A). (C) Sample from San Cristóbal Island, Galápagos, in which no cement is present in any intraskeletal pore. Note the sharp boundary between pore and skeletal wall (arrows). (Scale bars: 250 μm.)

  5. Fig. 5.
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    Fig. 5.

    Ωarag for ETP reef sites plotted against cement abundance (A) and bioerosion rate (B). Data points represent means (± SEM if available). See Table 5 and references cited therein for ETP bioerosion rates.

  6. Fig. 6.
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    Fig. 6.

    Typical ETP pocilloporid reef framework. (A) Vertical relief of framework structure ≈1 m. Dead surface is heavily encrusted with crustose coralline algae (red and purple hues). (B) Recently fractured pocilloporid reef framework. Note abundance of sponges (yellow and orange hues) growing within interlocking framework components. Diameter of Pocillopora branches are ≈1 cm. Photos were taken at Uva Reef by C.M.E. in 2003.

  7. Fig. 7.
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    Fig. 7.

    Relationship of Ωarag (△ in both plots) with temperature (A; ○) and phosphate concentration [PO4] (B; ●). High phosphate levels inhibit aragonite precipitation in natural seawater (see ref. 46 and references therein) and could also be a factor in the low cementation of ETP reefs. Note inverse relationship between Ωarag and [PO4]. See Table 1 for [PO4] and temperature values. Values represent approximate annual means.

Footnotes

  • ‡To whom correspondence should be addressed. E-mail: derek.manzello{at}noaa.gov

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