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Bleaching Event on Florida Reefs

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  • Bleaching Event on Florida Reefs

    Taken from an email server listing

    Extensive coral bleaching has been observed over the past several weeks at
    two inshore patch reef sites of the middle Florida Keys, U.S.A and recently
    at three inshore patch reef sites of Biscayne National Park as well. Some
    paling and bleaching has also been observed over the several week time
    period at two offshore reef sites in the upper Florida Keys. What follows
    are short bleaching reports from these three regions. Links to pictures will
    follow in a later email.

    Middle Keys Patch Reefs

    At two Florida Keys inshore patch reef sites, Cheeca Rocks and Coral
    Gardens, extensive coral bleaching has been observed affecting up to 80% of
    scleractinian corals. Cheeca Rocks and Coral Gardens are located offshore
    of the middle Florida Keys and these sites are currently being monitored as
    part of a dissertation study on coral disease. Five 16m2 permanent plots
    were established at each of these sites in August of 2004 and a total of 266
    corals at Cheeca Rocks and 350 corals at Coral Gardens have been monitored
    for the incidence of bleaching and disease since that time.

    On August 11th, 2005, I observed some partial bleaching affecting only a few
    of the monitored colonies. When I returned on August 16th, paling and
    partial bleaching was occurring on 19% and 33% of the monitored corals at
    Cheeca Rocks and Coral Gardens respectively. This bleaching was mainly
    affecting species of Colpophyllia natans and Montastrea faveolata. However,
    at this point all of the monitored colonies of Agaricia agaricites within
    the quadrats were completely bleached.

    On September 1st, I revisited the sites to find that 74% of monitored corals
    at Cheeca Rocks and 80% of monitored corals at Coral Gardens were
    experiencing some extent of bleaching (paling, partial bleaching, or total
    colony bleaching). The proportions of all colonies experiencing total
    bleaching (i.e. no observable color from zooxanthellae) were 11% at Cheeca
    Rocks and 15% at Coral Gardens. Species most affected by the bleaching were
    C. natans, M. faveolata, and A. agaricites. Other species found bleaching
    included M. annularis, M. cavernosa, Dichocoenia stokesii, Diploria clivosa,
    D. strigosa, D. labrynthiformis, Favia fragum, Meandrina meandrites, Mussa
    angulosa, Porites astreoides, P. porites, Siderastrea radians, S. siderea,
    and Stephanocoenia intersepta. Species other than scleractinian corals
    observed to be bleaching included Millepora alcicornis, M. complanata,
    Palythoa caribaeorum, Erythropodium caribaeorum, Briareum asbestinum, and
    some other gorgonians. The only notable exception was individuals of
    Mycetophyllia spp. which appeared healthy and experienced no noticeable

    The sites were again revisited on September 6th and no recovery was
    observed. In addition, three new Black-band diseases had begun affecting
    100% bleached colonies of C. natans at Coral Gardens and though they were
    not found within the quadrats, similar infections were observed on colonies
    of C. natans at Cheeca Rocks.

    Water temperature was recorded during each site visit with a YSI-30 at
    depths of 1 meter and 5 meters from the surface. Water temperatures in
    degrees Celsius were recorded as follows:
    Cheeca Rocks; 1m: 31.7, 5m: 31.7
    Coral Gardens: 1m: 31.8, 5m: 31.8
    Cheeca Rocks; 1m: 31.7, 5m: 31.7
    Coral Gardens; 1m: 32.0, 5m: 32.0
    Cheeca Rocks; 1m: 31.1, 5m: 31.1
    Coral Gardens; 1m: 31.1, 5m: 31.4
    Cheeca Rocks; 1m: 30.5, 5m: 30.3
    Coral Gardens; 1m: 30.6, 5m: 30.6

    Upper Keys Offshore Reef Sites

    In August of 2004, five 16m2 permanent quadrats were also established at two
    offshore reef sites in the upper Florida Keys, French Reef and Little
    Grecian. 366 corals at French Reef and 269 corals at Little Grecian have
    been monitored since the establishment of the quadrats and in recent weeks
    some bleaching has been observed. This bleaching is not nearly to the
    extent as that seen in the inshore patch reefs.

    On August 9th and 17th, 2005, these two sites were visited and monitored
    colonies were examined and their condition documented. At this time, some
    paling of A. agaricites was occurring. When sites were visited again on
    September 2nd, colonies of A. agaricites, M. alcicornis, M. complanata, S.
    radians, and S. siderea were noted to be bleaching. At total of 30% of
    monitored colonies at French Reef and 9% of monitored colonies at Little
    Grecian were experiencing some bleaching. 8% at French Reef and 1% at
    Little Grecian were totally bleached. When these sites were visited again
    on September 7th, the condition of the bleached colonies had not changed and
    no new bleaching had occurred.

    Temperature readings in degrees Celsius recorded during each site visit were
    as follows:
    French Reef; 1m: 30.6, 5m: 30.6, 10m: 30.6
    Little Grecian: 1m: 31.2, 5m: 30.9
    French Reef; 1m: 30.9, 5m: 30.8, 10m: 30.9
    Little Grecian: 1m: 31.3, 5m: 31.3
    French Reef; 1m: 29.6, 5m: 29.5, 10m: 29.5
    Little Grecian: 1m: 29.7, 5m: 29.4
    French Reef; 1m: 29.2, 5m: 29.3, 10m: 29.3
    Little Grecian: 1m: 29.1, 5m: 29.1

    Biscayne National Park Inshore Patch Reefs (Tyler B. Smith)

    On September 10th, 2005, A total of eight 10 meter transects were
    haphazardly laid at several inshore patch reef sites in Biscayne National
    Park. Three transects in the vicinity of Marker 9, two near Marker 13, and
    three in the area of Bache Shoals were conducted. Coral colonies that were
    under the line were recorded and their condition was evaluated. Condition
    categories were: okay, slightly pale (lightened), pale (very lightened),
    partial bleaching (patches of total bleaching), and bleached (100% w/o
    zooxanthellae color).

    Of the colonies measured [89 colonies, 10 species (incl. Palythoa
    caribaeorum)] 11% were normal and 89% exhibited some bleaching (30% were
    totally bleached and 58% had paling or patchy bleaching).

    In the transects, species affected were Agaricia agaracites, Diploria
    clivosa, Diploria strigosa, Montastrea annularis, Porites asteroides,
    Porites porites, Sidereastrea siderea, Stephanocoenia mechellini and
    Palythoa sp. Species unaffected were Dichocoenia stokesii

    Outside the transect, species affected were Acropora cervicornis (A. palmata
    was not seen at the reefs) and Montastrea cavernosa, Millepora complanata,
    M. alcicornis, Erythropodium caribaeorum (encrusting gorgonian) and Briaream
    asbestinum. Species that were unaffected included Eusmilia fastigiata.

    Inquiries regarding the middle Keys inshore patch reef sites and upper Keys
    offshore reef sites may be directed to Marilyn Brandt
    ([email protected]).

    For information regarding the inshore patch reef sites of Biscayne National
    Park contact Tyler Smith ([email protected]).

    Marilyn E. Brandt
    National Center for Caribbean Coral Reef Research (NCORE)
    Rosenstiel School of Marine and Atmospheric Science (RSMAS)
    University of Miami
    4600 Rickenbacker Cswy.
    Miami, FL 33149

    Ph. 305.421.4827 Fx. 305.421.4910
    “People are very open-minded about new things - as long as they're exactly like the old ones.”
    ...Charles F. Kettering

  • #2
    The follow up email offered this link to the pdf file and shows some before and after shots of the ongoing event.

    Last edited by GTR; 09-12-2005, 07:42 PM.
    “People are very open-minded about new things - as long as they're exactly like the old ones.”
    ...Charles F. Kettering


    • #3
      Please keep in mind, though this is in fact public information it's really not directed at hobbyists. It's for researchers looking to find the causes of these events and they are being closely monitored and shared when possible.

      “People are very open-minded about new things - as long as they're exactly like the old ones.”
      ...Charles F. Kettering


      • #4
        Interesting post, Steve. Thank you. :yesway:
        Fish eat poop....tastes just like chicken.


        • #5
          Look at the temps being measured on those reefs.
          The highest I see is 89.6° F.

          Coral Gardens showed temps of 89.24°F, 89.6°F, 88.52°F, 87.08°F at 16.4 feet from 11 Aug 2005 - 9 Sept 2005.

          I wonder what they measure in cooler times of the year, or is there such a thing in these areas?

          “People are very open-minded about new things - as long as they're exactly like the old ones.”
          ...Charles F. Kettering


          • #6
            WOW the pics are really looking bad...


            • #7