"The final rock was placed the night of Dec. 20," said NOAA Fisheries Alaska Regional Administrator Jim Balsiger. "Rigorous study and monitoring will allow NOAA Fisheries and University of Alaska scientists to determine if the materials and design are enhancing marine habitat as expected."
The two new reefs lie just offshore of Adlersheim Lodge north of Juneau. One is located inside Yankee Cove and the other immediately outside the peninsula protecting the cove.
NOAA Fisheries initiated the project through discussions with the Alaska Department of Transportation, reviewed the research proposal and obtained all required state and federal permits. The University of Alaska Fairbanks designed the project and study plan and completed extensive surveys of the seafloor and existing local rocky reefs. The Alaska Department of Transportation and the Federal Highway Administration provided engineering expertise, funding, and contracting services for the project as partial mitigation for the planned Juneau Access Improvement Project. The Army Corps of Engineers has not yet issued a permit for the proposed road, but the transportation agencies decided to proceed with the habitat enhancement in advance.
Photo courtesy of Daniel Okamoto Yankee Cove, site of the artificial reefs. One reef is located inside the cove and the other is immediately outside the peninsula protecting the cove.
NOAA Fisheries worked with partners in 2006 and 2007 to place manmade artificial reefs to enhance habitat in Shotgun Cove near Whittier, Alaska. Local groups facilitated sinking vessels north of Auke Bay in 2003 for recreational diving opportunities, but not for fish habitat.
The Lynn Canal reefs are two flat-topped structures made of angular quarry rock two layers thick with a maximum height of about six feet, Walker said. The two structures, each 30 feet wide by 100 feet long, were placed on sandy bottom and incorporate about 30 percent open space between the rocks to provide habitat for fish and marine invertebrates such as juvenile rockfish, shrimp and eels. The depth and design are intended to support the settling and growth of kelp and other seaweeds that provide ideal spawning habitat for Pacific herring.
University of Alaska Fairbanks graduate student and diver Daniel Okamoto completed extensive baseline research before the reef was installed. Okamoto is advised by University professors Dr. Ginny Eckert, a marine ecologist, and Dr. Mike Stekoll, who has broad expertise in the study of marine algae.
Photos courtesy of Daniel Okamoto An anemones and a ronquil in Yankee Cove are some of the species that will likely use the new reefs.
Local contractor Trucano Construction built the reefs to specifications by placing rock at the site from a barge. Okamoto will conduct experiments and post-construction monitoring to assess colonization and use of the rock structures by fish, kelp and other seaweeds, marine invertebrates such as sea urchins, sea cucumbers, sea stars, nudibranchs, bryozoans, sponges, and the myriad of other animals that inhabit the underwater habitats of Lynn Canal.
Photos courtesy of Daniel Okamoto A basket star.
NOAA's National Marine Fisheries Service (NOAA Fisheries Service) is dedicated to protecting and preserving our nation's living marine resources through scientific research, management, enforcement, and the conservation of marine mammals and other protected marine species and their habitat. To learn more about NOAA Fisheries in Alaska, go online to www.alaskafisheries.noaa.gov or www.afsc.noaa.gov.