BULLETIN OF MARINE SCIENCE, 81(3): 481–496, 2007
481
Bulletin of Marine Science
© 2007 Rosenstiel School of Marine and Atmospheric Science
of the University of Miami
IMPACTS OF BOTTOM TRAWLING ON A DEEP-WATER
OCULINA CORAL ECOSYSTEM OFF FLORIDA
John K. Reed, Christopher C. Koenig, and Andrew N. Shepard
ABSTRACT
In 1984, a portion of the deep-water Oculina coral reef ecosystem of eastern
Florida was protected as the Oculina Habitat Area of Particular Concern (OHAPC),
prohibiting bottom trawls, longlines, dredges, and anchors. Unfortunately, the
northern two thirds of the reef system remained open to these gear until 2000 when
the OHAPC boundaries were expanded to 1029 km
2
. In the 1970s, the Oculina reefs
were teeming with large spawning aggregations of grouper and snapper. By the early
1990s, commercial and recreational ishing had decimated the ish populations, and
the coral had been severely impacted by bottom trawling for rock shrimp. Histori-
cal photographic transects, taken in the 1970s with the Johnson-Sea-Link sub-
mersibles, provide crucial evidence of the status and health of the reefs prior to
heavy ishing and trawling activities. Quantitative analyses of photographic images
by point count reveal drastic loss of live coral cover between 1975 and 2001. Six
coral reef sites had nearly 100% loss of live coral, whereas only two reefs which were
within the boundaries of the original OHAPC since 1984 survived and were not
impacted by trawling. Management and conservation plans for deep-sea coral reef
ecosystems worldwide must be based on sound scientiic understanding as well as
adequate surveillance and enforcement; this study will help build a foundation for
this understanding.
he deep-water Oculina varicosa Lesueur, 1821 coral reef ecosystem is known only
of the east coast of Florida. At depths of 70–100 m this azooxanthellate, branching
coral produces 1–2 m diameter colonies that coalesce into thicket-like habitats and
high-relief bioherms that are similar in structure to deep-water Lophelia coral reefs
(Reed, 2002a,b; Reed et al., 2005, 2006). he majority of this Oculina habitat is known
between 27°30´N (Fort Pierce) and 28°30´N (Cape Canaveral) in a zone 2–6 km wide,
paralleling the 80°W meridian (Avent et al., 1977; Reed, 1980). Historical accounts in
the 1970s and 80s indicate high densities of economically important reef ish includ-
ing large spawning aggregations of grouper associated with the coral habitat (Gilmore
and Jones, 1992; Koenig et al., 2000, 2005; Reed et al., 2005, 2006). In 1984, the South
Atlantic Fishery Management Council (SAFMC) designated one third of the known
reef system (315 km
2
) as the Oculina Habitat Area of Particular Concern (OHAPC)
to protect the coral habitat from bottom trawling, dredging, longlines, and anchor-
ing. Unfortunately, the northern two thirds of the reef system remained unprotected
and was legally open to these mechanically destructive activities. During the 1980s
and 90s, bottom trawling within Oculina ecosystem was primarily for rock shrimp
and brown shrimp and this was the primary cause of major habitat destruction. Also
commercial dredging for calico scallops was prominent in the 1970s–1980s but over-
ishing and destruction of habitat caused the collapse of the industry. By the early
1990s, grouper spawning aggregations, which in the 1970s consisted of hundreds of
grouper on each reef, were virtually eliminated primarily by commercial and recre-
ational hook-and-line ishing (Koenig et al., 2000, 2005). his stimulated the SAFMC
to ban hook-and-line ishing for grouper in 1994 to test the efectiveness of a ishery
reserve. In 2000, the Oculina HAPC boundaries were expanded to 1029 km
2
and the