Marine Habitat Damage Assessment Restoration, and Enhancement

Summaries of CSA Internation's Representative Marine Habitat Damage Assessment, Restoration, and Enhancement Projects:

• Damage Assessments and Restorations Associated with Vessel Groundings
• Transplantation of Hard Corals to Avoid Dredging Impacts
• Biological Enhancement of a Salt Water Lagoon in the Bahamas
• Artificial Reef Design, Construction, and Development
• Seagrass and Marine Habitat Studies Offshore Florida
• Recurrent Algal Blooms Off Palm Beach County
• Exxon Valdez Oil Spill Assessment

CSA International has conducted numerous marine habitat assessment and restoration projects associated with vessel groundings. These projects have been in Florida (particularly the Florida Keys National Marine Sanctuary), the Federated States of Micronesia, Mexico, and Puerto Rico.

Looe Key Reef Grounding Site
CSA International provided diverse services during a four-year period for the Natural Resource Damage Assessment (NRDA) at the R/V COLUMBUS ISELIN grounding site on Looe Key Reef in the Florida Keys National Marine Sanctuary. During the initial damage assessment, CSA International scientific divers determined the approximate size of the impacted area, collected underwater video and still camera photographic data, determined the predominant fauna impacted by the grounding, and prepared a report. CSA International staff also arranged for the collection of aerial photographs of the damaged areas and analyzed the photographs to more accurately determine the actual aerial extent of damages to the reef. CSA International scientists returned to the grounding site to assess the effects of a November 1994 tropical storm on the damaged reef spurs and rubble areas created during the grounding. CSA International provided on-site technical review of rubble removal operations at the grounding site. The work included continuous monitoring of construction activities, verification of quantities of rubble removed, supervision of turbidity measurements, and coordination with staff of the U.S. Department of Commerce, National Oceanic and Atmospheric Administration. CSA International scientists also were involved in reviews of the damage assessment documents, meetings with Department of Justice attorneys, and the final resolution of the damage assessment.

Key Largo Grounding Sites
CSA International provided Natural Resource Damage Assessment (NRDA) services to the U.S. Department of Commerce, National Oceanic and Atmospheric Administration for two grounding sites off Key Largo, Florida. CSA International attended Scoping Meetings and prepared Work Plans and Field Survey Plans for the grounding sites of the M/V ALEC OWEN MAITLAND and M/V ELPIS on coral reefs in the Florida Keys National Marine Sanctuary. Field surveys of the two grounding sites were conducted. A report with maps was produced based on analyses of the field data that included in situ measurements of excavated craters and scars, still photographs, and video. Survey data were used for an engineering design and operational plan for structural restoration of the damaged coral reefs. After the first two years, CSA International provided underwater inspection and construction review services to NOAA for another two years at the vessel grounding sites. These services included preparing for and executing nearly continuous on-site review of contractor construction activities during reef restoration work at the two grounding sites. CSA International advised the Project Engineer of NOAA and the Field Representative of the U.S. Army Corps of Engineers regarding the project, along with documenting and verifying project progress. Additional responsibilities included interfacing with the government's contractor who conducted turbidity monitoring and alerting NOAA Sanctuary personnel of any potential environmental problems associated with the construction effort.

CSA International conducted diver reconnaissance surveys of scleractinian coral colonies on rock habitat within the dredging impact area along the north edge of the Fort Pierce Harbor navigational channel. The surveys for the U.S. Army Corps of Engineers, Jacksonville District in 1994 provided approximate number and location of coral colonies within the survey area. Wormrock also was recorded in the survey area. During 1995, CSA International conducted surveys to relocate hard coral colonies (Oculina sp.) along the north slope of the channel and to transplant these corals to a suitable offshore location. Coral colonies were removed from the channel and successfully reattached to a shallow reef adjacent to the inlet. CSA International collected and analyzed video and still photographs to document the operations and monitor the success of the coral reattachment into 1996.

CSA International has been working on the biological enhancement of a saltwater lagoon in the Bahamas since 1989. Initial baseline and habitat mapping surveys were conducted of Alder Cay and Frozen Cay in the Berry Islands. CSA International provided recommendations for enhancing the marine habitats and, in particular, improving a saltwater lagoon on Alder Cay. Core borings were taken and sediment depth probes were made in the lagoon prior to its dredging. A vegetation survey also was conducted of low-lying areas on Alder Cay where the dredged material was to be deposited. CSA International then developed options for biologically enhancing the saltwater lagoon. Site visits were made to assess the post-dredging conditions within the lagoon. Possible courses of action were outlined, including transplanting hard bottom and associated organisms into the lagoon. Heavy wire mesh fences were erected across the two entrance channels of the lagoon to prevent entry of large predators. Hard bottom was placed within the lagoon and hard corals, soft corals, and sponges were transplanted onto the rock structures. Following the initial transplantation, large reef fish were added to the already existing fish population of the lagoon. A monitoring program also was designed to measure the effectiveness of the project. This work was conducted with cooperation of the Bahamian government. CSA continues to monitor the biological enhancement of this saltwater lagoon.

CSA International designed, fabricated, and installed a series of artificial reef modules offshore Sunny Isles, Florida for the Dade County Department of Environmental Resources Management. The project was designed to mitigate two hard bottom areas that were damaged by a dredge during the Sunny Isles Beach Restoration Project. Three different module designs were selected due to their suitable structural complexity and similarity to the naturally occurring hard bottom areas. Subsequently, CSA International constructed and deployed additional artificial reef modules in the three different designs for Palm Beach County. The modules purchased by Palm Beach County were deployed on open sand to enhance the county's overall artificial reef program.

CSA International conducted two major seagrass and marine habitat studies for the U.S. Department of the Interior, Minerals Management Service. The first project was the "Southwest Florida Nearshore Benthic Habitat Study" that covered the southwestern coast of Florida from Charlotte Harbor through the Dry Tortugas. The study area included approximately 10,000 square miles in water depths ranging from 1 to 30 meters. The project involved extensive aerial photography, photointerpretation, and field verification. Subsequently, CSA International conducted the "Florida Big Bend Seagrass Habitat Study." Remote sensing overflights were made with quantitative signature control stations established and targets deployed at the stations to mark their locations on the aerial imagery. Field investigations were conducted to verify information obtained from the remote sensing overflights. Diver tows, an underwater video system, and quantitative photographs were used to verify the imagery and to investigate seasonal changes in seagrass beds. Following the passage of Hurricane "Elena" through the study area, an additional survey was completed to investigate damage to the previously mapped seagrass beds.

A baseline survey to determine the effects of recurrent Codium blooms on the reefs of Palm Beach County was commissioned by the Florida Marine Fisheries Commission. CSA International was subcontracted by Florida Atlantic University to participate in the survey and contribute to the reports and recommendations on how to respond to problems associated with the nuisance algae. Video data were collected along transects across the reef and repetitive photographic transect and fish count data were taken at specific reef locations.

CSA International completed a three-task program designed to evaluate the EXXON VALDEZ oil spill for the U.S. Department of Commerce, National Oceanic and Atmospheric Administration. The first task provided scientific data necessary to assess the relative degree of oil contamination and the effectiveness of natural removal processes. CSA International conducted monthly surveys during the winter of 1989-1990 at 18 sites in Prince William Sound. Quantitative beach profiling, photographic and videotape documentation, surface and subsurface sediment sampling, and extensive visual observations of surface oiling were completed at each site. The second task involved identification and evaluation of the possible technologies that could be used in clean-up operations during the spring of 1990. As part of this task, CSA International conducted and summarized a three-day workshop in Anchorage attended by over 200 Federal, State, and local regulatory personnel, oil and gas industry and commercial fisheries representatives, natives, and members of the scientific community and academia. The third task resulted in a CSA International review and summary of the impacts and environmental recovery of past oil spills which were comparable to the EXXON VALDEZ incident.