Diadema antillarum survey data - Panama 2014

Data collected by Joshua Hamilton, Jonathan Choi, and Nicole
Zenes while affiliated with Princeton University in February 2014. For
additional information, contact Jonathan Choi at jonathan.j.choi[at]duke.edu. This
document was created on 12 July 2018.
We
conducted our surveys in February 2014 at three reef sites near Bocas del Toro,
Panama (9.33° N, 82.25° W): Coco Key, a backreef site dominated by
scleractinian corals and sponges; Coral Key, a backreef site primarily
dominated by gorgonian corals and Millepora,
and Salt Creek, a forereef site characterized by scleractinian coral dominance
including large stands of Acropora. The
two backreef sites were characterized by lower wave-action relative to Salt
Creek. D. antillarum individuals were present at all sites, despite not
sampling D. antillarum in our
quadrats at all sites.
We
placed 30 m line transects on to the reef at random by determining a clock-face
direction with the aid of a wristwatch and then placing the transect in the
direction using our boat as a reference point.
We placed 1 m2 quadrats every 4 m on alternating sides of the
transect line. We counted all Echinometra viridis, E. lucunter (binned
as Echinometra spp. for analysis),
and D. antillarum individuals within
the quadrat. We estimated percent coral,
algal, and bare substrate cover by partitioning the quadrat into 100
equal-sized squares with twine and recording the dominant form of substrate
within each square. We stratified algal
cover into broad functional groups: fleshy macroalgae (e.g. Dictyota spp., Cladophora spp., etc.),
calcareous algae (e.g. Halimeda spp.
& Galaxaura spp.), and encrusting coralline algae (e.g. Porolithon spp.). We took the average of percent coral and
algal cover estimates of two independent observers in order to minimize
personal bias.