INTRODUCTION:

During a storm in March 1998, the large container ship, C/V Hind, broke anchor and damaged 781 m2 of coral reef and 4,258 m2 of live hardbottom habitat offshore Ft. Lauderdale, Florida USA (Figure 1). The grounding dislodged and fragmented many reef-building corals and created flat topped, scarified, reef substrate in several places (Figure 2). In May 1998 over 300 stony corals were reattached to reef substrate in 12 zones distributed along the path of the damage (Figure 1). At the time of reattachment, however, no information on the species, size and condition of the reattached corals was recorded.

The purpose of this project was to:

1. identify and assess as many reattached corals within the zones as possible,

2. map a subset of at least 100 representative reattached corals as well as at least 25 naturally occurring reference corals for future monitoring,

3. assess the physical (secure, loose, or missing) and health (living, % tissue loss, disease, bleaching, lesions, dead) status including underwater photographs of these reattached and control corals and

4. establish permanent transect locations at scarified reef sites and nearby undamaged sites to compare recruitment of new stony corals.

METHODS:

Reattached corals in each zone were identified and their physical (secure, loose or missing) and health condition (dead or living including information on bleaching, % tissue loss, disease, lesions) recorded. Identified reattached corals in each zone were mapped by measuring their distance and azimuth from an eyebolt that marks the center of each zone (Figure 3).

A randomly chosen subset of reattached corals (10-15) in each zone was tagged to facilitate future monitoring (Figure 4). 30 undamaged corals of similar species and size distribution as the tagged reattached corals were identified and tagged and will serve as controls against which the health of the reattached corals will be monitored.

All of the tagged reattached and control corals were photographed with a 0.75m2 framer. 3 permanent 10m transects were installed in a scarified reef area and in an undamaged similar reef area (Figure 5). Coral recruitment was assessed using 0.25m2 quadrats placed at each meter along the transects (Figure 6).

RESULTS: 333 of the 387 corals reattached in May 1998 were identified and their condition recorded (Table 1) (for examples of reattached corals see Figures 7-9). 285 (74%) of the reattached corals were living and securely attached to the substrate (Table 1). 157 reattached corals were tagged, photographed and their health condition recorded (Figure 10). 30 undamaged (control) corals were tagged, photographed and their health condition recorded (Figure 11). Coral recruitment of on the scarified reef substrate was higher (22 recruits/15m2) than on the similar undamaged substrate (2 recruits/15m2). However, the abundance of other sessile invertebrates (gorgonians, zooanthids, sponges etc) was greater on the undamaged site.

DISCUSSION:

Coral colonies are frequently dislodged and/or fragmented as the result of vessel groundings. Damaged corals may be susceptible to tissue death, disease and algal overgrowth. As this project demonstrates, damaged colonies can be saved if they are reattached to the substrate. In addition to simply saving the loose colonies and fragments, reattaching corals may facilitate the recovery of a damaged area by releasing larvae for recruitment, attracting recruits, and maintaining substrate complexity for fisheries. The reattachment of corals as a restoration method is especially appropriate for the high latitude reefs found off southeast Florida where coral cover and recruitment may be low prolonging reef recovery. The assessment and continued monitoring of the damaged area and restoration is vital to evaluate the success of the activities, to determine if additional effort is required, and to follow reef recovery.

ACKNOWLEDGEMENTS:

We would like to thank Lance Robinson, Brian Ettinger and Judy Robinson for their invaluable assistance with this project.

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