David G. Zawada
Barbara H. Lidz
2013
<p>Seabed classification is essential to assessing environmental associations and physical status in coral reef ecosystems. At Pulaski Shoal in Dry Tortugas National Park, Florida, nearly continuous underwater-image coverage was acquired in 15.5 hours in 2009 along 70.2 km of transect lines spanning ~0.2 km<sup>2</sup>. The Along-Track Reef-Imaging System (ATRIS), a boat-based, high-speed, digital imaging system, was used. ATRIS-derived benthic classes were merged with a QuickBird satellite image to create a habitat map that defines areas of senile coral reef, carbonate sand, seagrasses, and coral rubble. This atypical approach of starting with extensive, high-resolution <i>in situ</i> imagery and extrapolating between transect lines using satellite imagery leverages the strengths of each remote-sensing modality. The ATRIS images also captured the spatial distribution of two species once common on now-degraded Florida-Caribbean coral reefs: the stony staghorn coral <i>Acropora cervicornis</i>, a designated threatened species, and the long-spined urchin <i>Diadema antillarum</i>. This article documents the utility of ATRIS imagery for quantifying number and estimating age of <i>A. cervicornis</i> colonies (<i>n</i> = 400, age range, 5–11 y) since the severe hypothermic die-off in the Dry Tortugas in 1976–77. This study is also the first to document the largest number of new colonies of <i>A. cervicornis</i> tabulated in an area of the park where coral-monitoring stations maintained by the Fish and Wildlife Research Institute have not been established. The elevated numbers provide an updated baseline for tracking revival of this species at Pulaski Shoal.</p>
application/pdf
10.2112/JCOASTRES-D-12-00078.1
en
Coastal Education and Research Foundation
Possible return of Acropora cervicornis at Pulaski Shoal, Dry Tortugas National Park, Florida
article