Scleractinian corals are slowly disappearing, disrupting the marine ecosystems that they build. Active restoration efforts aim to improve coral reef habitats and rebuild coral communities by out-planting young coral in highly-damaged areas. However, this process often relies on concrete bases made with Portland cement. The manufacturing of cement is a key contributor to global greenhouse gas emissions, so coral propagation presently contributes to the destruction of scleractinian reefs via global warming. We examined the larval settlement of a robust coral (Porites astreoides) on a variety of concrete alternatives designed to have lower greenhouse gas emissions than traditional concrete. The goal of our study was to identify a greenhouse gas-efficient concrete alternative that maximizes the settlement of P. astreoides larvae, and minimizes greenhouse gas emissions for potential use in reef restoration efforts. We experimentally examined and quantified the settlement and metamorphosis of P. astreoides larvae on seven concrete tile types. Although average larval recruitment differed among tile types, a Kruskal-Wallis ANOVA revealed that these differences were not significant (p=0.23). The variance between tiles of the same composition leads us to recommend at least 10 replicates in future experiments to ensure statistical power to differentiate between materials. Lower greenhouse gas alternative concretes were not significantly better or worse than ceramic tiles or traditional concrete for the settlement of P. astreoides larvae and thus could be suitable for coral settlement.

Primary Presenter: Dalia Bercow, Haverford College (drbercow@gmail.com)

Authors:

Dalia Bercow, Haverford College  (drbercow@gmail.com)

K. Halimeda Kilbourne, University of Maryland Center for Environmental Science  (kilbourn@umces.edu)

Elizabeth North, University of Maryland Center for Environmental Science  (enorth@umces.edu)

Scott Hunsicker, University of Maryland Center for Environmental Science  (shunsicker@umces.edu)

Ryan Hoover, Maryland Institute College of Art  (rhoover@mica.edu)