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The East
Fourteen EF Culverts Artificial Reef Enhancement |
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The East
Fourteen EF Culverts Artificial Reef Enhancement |
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| The East Fourteen EF Culverts Artificial Reef
Enhancement, LORAN C 45161.5/61899.4 The Jacksonville Reef Research Team provided engineering services to the City of Jacksonville's Department of Parks, Recreation, and Entertainment as part of the reef enhancement program. The following engineering services were provided: As specified in the Artificial Reef Bid Specification for Engineering Services, members of the Jacksonville Reef Research Team completed a pre-deployment bottom survey of the specified area at the East Fourteen (EF) reef placement area east of Jacksonville, Florida. The original pre-deployment survey was conducted on April 21, 1996 at Loran C 45157.5/61901.2, approximately 0.25 miles north of the EF flag. However, after consulting with the Jacksonville Offshore Fishing Club, a more suitable location was discovered. The new location provided a needed trolling path for local fishermen within the EF permitted area. A second pre-deployment survey was conducted on May 26, 1996. The survey location was located at Loran C 45161.5/61899.4, on an approximate bearing of 94°, 16.4 nautical miles from the sea buoy at the mouth of the St. Johns River. The site is within the EF Reef placement area at an approximate bearing of 350°, one nautical mile from the EF flag. The site is located in approximately 79 feet of water with the bottom consisting of sand and shell material. A circular sweep of the bottom with a radius of 165 feet was performed and revealed no natural or artificial live bottom structures. Sand ripples, which measured less than two inches in height and one foot apart were observed. Several shells were observed in the search area. Photographs that were recorded during the pre-deployment bottom survey follow:.
Based on the results of the bottom survey, the location described above was suitable for placement of artificial reef material. Transportation and Off-Loading Three barge loads of concrete pillboxes, culverts, and other assorted concrete structures were off-loaded from a barge on May 26, May 28, and June 5, 1996. The tug Rachel towed the barge to a buoy placed by the Team at Loran C 45161.5 / 61899.4. An anchor composed of concrete culverts and steel cable was deployed from the barge at the buoy. Subsequently, the tug disconnected from the barge to assist in maintaining the barge position at the buoy. The concrete material was pushed overboard using a backhoe. On May 26, 1996, Team members Marc Dillon, Tim Armstrong, Allison Rogers, and non-Team member Joanne Dillon aboard Endless Possibilities II placed the buoy and observed the off-loading of the material. No problems were observed during off-loading of the material. On May 28, 1996, Tim Armstrong, aboard Endless Possibilities II returned to the buoy and observed the off-loading of the material. No Team members could be present for the third material drop on June 5, 1996. Surface sonar observations from Endless Possibilities II indicated several dense clumps of material with a profile of approximately 15 feet and several lower profile clumps. Pictures of the barge and tug with material prior to and during off-loading of the concrete material are shown below:
On June 23, 1996 RRT members Captain Marc Dillon, Jim Cribb, Daniel Hughes, and Jim Barnes aboard Endless Possibilities II returned to the site to perform a deployment survey. Divers reported the highest profile to be 15 feet, consisting of a stack of concrete pillboxes and culverts. This location (Loran C 45161.5/61899.4) was used as the temporary benchmark for mapping and observations conducted during the deployment survey. The material is predominantly densely stacked with the occurrence of several less densely placed clumps. On the 0-degree radial (measured from the benchmark), the material is fairly tightly distributed with culvert and pillbox units stacked, touching, or laying approximately 5 feet to 10 feet apart. Material on the 0-degree radial was found as far as 83 feet from the benchmark with a maximum profile of 10 feet. On the 60-degree radial, the material is less densely clustered than the 0-degree radial with most units touching. Material was scattered as far as 101 feet from the benchmark. Maximum profile on the 60-degree radial was approximately 14 feet. Material was densely distributed on the 120-degree radial, with culverts observed out to 140 feet, which was the maximum distance for material at this radial. Maximum profile on the 120-degree radial was 10 feet. A dense clump of culverts was observed on the 180-degree radial from the benchmark out to a maximum distance of 150 feet with a maximum profile of 13 feet. Dense clumps of material (culverts and bridge pilings) were observed on the 240-degree radial separated by intervals of sand out to a maximum distance of 140 feet with a maximum observed profile of 13 feet. A similar configuration was observed on the 300-degree radial. The 300-degree radial had a maximum profile of 15 feet out to a maximum distance of 90 feet from the benchmark. Steel rebar was observed on several pillboxes and culverts. Fish observed at the reef placement during the deployment mapping (two dives) included tomtates, black sea bass, greater amberjack, and barracuda. A deployment map and underwater photographs of the reef material are presented in Attachment 4. The map was prepared using methods described in "Underwater Methods for the Jacksonville Reef Research Team," November 1991.
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