• Harvey Thorleifson, Chair
    Minnesota Geological Survey
  • Carrie Jennings, Vice Chair
    Minnesota Geological Survey
  • David Bush, Technical Program Chair
    University of West Georgia
  • Jim Miller, Field Trip Chair
    University of Minnesota Duluth
  • Curtis M. Hudak, Sponsorship Chair
    Foth Infrastructure & Environment, LLC


Paper No. 3
Presentation Time: 9:30 AM


JOHNSON, Claudia C.1, BEEKER, Charles D.2, GREEN, Robin M.1 and KAUFFMAN, Erle G.1, (1)Geological Sciences, Indiana University, 1001 E. 10th St, Bloomington, IN 47405, (2)Kinesiology, Indiana University, Bloomington, IN 47405,

Cannons from the Quedagh Merchant ship of Captain Kidd remained secluded in shallow waters of the Caribbean Sea, just south of the island of Hispaniola, for three hundred years. Discovered in 2007, these cannons reveal the history of biotic succession on archaeological artifacts in the marine realm. Investigations of the biota disclose sponges and corals as dominant macrofauna on the original iron substrate, but only advanced stages of colonization were preserved. Sponges were degraded but consisted of several generations of encrusting overgrowth. The coral Diploria strigosa was dominant in the last successional stage, although smaller corals such as Montastrea and Siderastrea were also present. Microalgal turf was widespread over deceased parts of sponges and corals. Lifted from the sea for scientific analyses, one cannon was subjected to electrolysis to remove biota in order to expose the cannon’s original markings, and thus place of origin. Below the cannons were Acropora palmata fronds, indicating that the ship blasted through these elkhorn corals prior to settling on the sea floor. The presence of fronds beneath the cannons reveals that Diploria corals were secondary growth to the ecosystem in this region. Recolonization of A. palmata on the adjacent sea floor, however, indicates ecosystem resiliency after damage, and persistence of environmental conditions conducive to sustained growth of these endangered corals. In contrast to the cannons submerged for multiple centuries, freshly conserved cannons placed in the sea in 2004 at a nearby site yielded abundant colonizing coral species of Siderastrea and no further evidence of successional stages. These submerged cultural resources provide not only a haven for corals - biological resources that are in decline worldwide – but also yield important data on ecosystem composition over the last three hundred years that hint to future restoration and conservation practices.
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