Through the use of benthic video surveys and existing spatial data, CSA mapped the cable route of least impact through the environmentally sensitive reef system populated with listed endangered coral species, such as the staghorn coral (Acropora cervicornis) and elliptical star coral (Dichocoenia stokesii). Using underwater navigation systems, CSA divers carefully delineated the cable route through the reef, relocating listed corals from the planned cable pathway. After cable deployment, CSA divers relocated and re-attached additional benthic organisms dislodged during the cable installation.
As a part of mitigation efforts for the cable installation, CSA also removed and disposed of more than 400 tires from Osborne Reef, a well-meaning but unsuccessful artificial reef created from the placement of over 1 million tires in the 1970s. Unfortunately, over time, the tire bundles broke apart and drifted onto adjacent natural reefs damaging them in the process. The tires removed for mitigation were those closest to the natural reef edge with the highest mobility and greatest potential for crushing and covering the natural reef.
During the spring of 2014, a 6-month post-installation coral monitoring effort was performed to document and assess coral reattachment success and relative health as well as to evaluate selected control specimens. Prior to and following installation, seven reattachment areas were established to relocate the 149 specimens moved away from the cable route to minimize impacts related to installation activities. These specimens were predominantly hard corals, particularly the target species Acropora cervicornis and Dichocoenia stokesii. The 6-month post installation monitoring indicates that the reattached specimens are generally in very good condition and are responding well to the relocation. CSA will continue biological monitoring through 2017 in accordance with the permit conditions outlined in federal, state, and local permits issued to the project.
“The execution of this effort from project planning, regulatory interactions, multi-agency permitting, installation assistance, mitigation, through continued monitoring demonstrates CSA’s unique ability to offer a complete suite of the highest quality in-house environmental permitting, science, and marine operation services available anywhere. I am proud of our staff and their dedication to our clients and to their work to help protect our dynamic and sensitive marine environment,” said Kim Olsen, Business Line Manager for CSA’s Permitting business line.
For more information on CSA and the services it offers, visit our website at www.csaocean.com.
