Bonner bridge material will enhance Oregon Inlet reefs

Jan 15, 2016

Credit Pamela Malec Landrum, Roanoke Island Outfitters and Dive Center

The only way you’ll be able to cross the Bonner Bridge a couple years from now is if you’re underwater.  The span is planned to be demolished in Fall of 2018 and the construction debris will be used to enhance four artificial reefs near Oregon Inlet.  Today on the Down East Journal, how the Dare County project will benefit the environment and the economy.

Known as the Graveyard of the Atlantic, our coastline is littered with hundreds of shipwrecks that serve as habitat for fish and invertebrates, like sponges and soft corals.  It’s what makes North Carolina a diving destination.

“We’re number two in the world for shipwrecks.”

Co-owner of Roanoke Island Outfitters and Dive Center Pam Landrum describes what it’s like to dive near Oregon Inlet, at the wreck of a 441 foot cargo ship known as Zane Grey.

“Depending on the conditions, it’s close to the Inlet, so you have to catch the tides right to see anything.  But it’s a ship and there’s tons of fish.  There’s growth on the wreck and it attracts fish and it’s a reef like the Caribbean.”

Credit Pamela Malec Landrum, Roanoke Island Outfitters and Dive Center

In addition to a diving spot, the Zane Grey attracts recreational fisherman.

“There’s flounder, and triggers and tautogs and you see amber jack, bluefish, it just depends on the time of the year.”  

These wrecks and the reefs that grow on them are important economically and ecologically.  Beyond recreational diving and fishing opportunities, waters of our coast host a biologically diverse ecosystem essential to many organisms for spawning, breeding and feeding.    

The North Carolina Division of Marine Fisheries realized the importance of sustaining these ecosystems in the 1970’s when they started the Artificial Reef Program.  Today, there are over 60 artificial reefs stretching along the entire coast, in the ocean and in estuarine waters.  Artificial Reef Coordinator Jason Peters says these systems are made from recycled oyster shells, sunken ships, train box cars, reef balls and demolition waste.

“We sort of design our reef around a particular goal.  If we’re looking to enhance fish populations, we will select materials that are more suited for fish so we’ll pick materials like pipe, ships or discarded concrete from construction projects.  So that provides great fish habitat.  In the estuary, we sort of lean towards oyster restoration type of goal.  So oyster shell, pieces of limestone marl, things of that nature.  The beauty of those types of reefs is that they also attract fish.”

Credit Pamela Malec Landrum, Roanoke Island Outfitters and Dive Center

The goal of the State’s artificial reef program is, first, to bolster fish populations and make North Carolina attractive to anglers and divers.  

“The real objective that we’re trying to accomplish is to improve user access to reefs.  Fishing opportunities, diving opportunities.  We’ve done a great job throughout the state in my opinion creating those opportunities but as time goes on, artificial reefs sort of degrade and they go away, just natural processes.  The ocean is a harsh environment.” 

The artificial reef program aims to build new reef systems and enhance existing ones.   Just last week, the Division of Marine Fisheries along with the Department of Transportation announced plans to improve four artificial reefs near Oregon Inlet.  When DOT finishes the Bonner Bridge replacement span, they’ll demolish the old bridge and transport about 45 thousand tons of concrete material to the reef sites. 

“They’re planning on basically chopping sections of the bridge and setting those sections on large barges and push it overboard.”

An aerial photo of the Bonner Bridge and Oregon Inlet
Credit NCDOT

Peters makes it sound easy, but it’s a complicated process that will take about 10 months. 

“At each reef, we’re looking putting about 15,000 tons of concrete bridge spans.  So diving around that material, you’ll see basically long pieces of roadway.”

Not only does the material give fish a place to breed and hide, it will dramatically cut down on the costs of discarding demolition debris, which would otherwise end up in a landfill.  This project is already several years in the making.  Peters says there have been considerable environmental and safety concerns to address.  For instance, before the bridge pieces are placed on barges, they must undergo rigorous testing.

“There’s a variety of evaluations we go through to test the material to make sure there are no chemicals that could be damaging to the environment.”

Then there’s the transportation of the bridge pieces to the sites through Oregon Inlet, which has a reputation for being difficult to navigate.  Another part of the planning process involves placing materials at the site in such a way boats don’t hit it once it’s in the water.  The depth at sites range from 40 to 60 feet deep.  When offloading concrete from the barge, workers will have to maintain the minimum vertical clearance requirements as required by the Coast Guard.

Credit Pamela Malec Landrum, Roanoke Island Outfitters and Dive Center

The material will be placed at four existing artificial reefs, including the Oregon Inlet Reef, the location of the Zane Grey wreck.  All of these are already established reefs, some with a longer history than others.   So when the new bridge pieces are finally in the water, it shouldn’t take long for fish to move in.  Peters says it will be an “oasis” for transient fish.  

“University studies have indicated that fish can recruit to new artificial reef material within a matter of hours.  Of course, those might not be resident at the time, but they will start to utilize the reef very, very quickly.”

Establishing a biological community takes a little longer.

“In the summertime, there’s typically more spawning invertebrates and that sort of develops the basis of a biological community.  You get your sponges, your algae, your corals and those sessile invertebrate organisms again provide the basis for that biological community and then once you’ve established that, your resident fish start to move in.  That can take a couple of months.”

But it could take years before the reefs become well-established and thriving ecosystems.  Take artificial reef 145 for example.  It’s located about nine nautical miles from Oregon Inlet.  It’s the final resting place of the 185 foot vessel “Advance II”, a 115 foot landing craft, and two Coast Guard aircraft.  Diver Pam Landrum recalls diving at the site last year.

Credit Pamela Malec Landrum, Roanoke Island Outfitters and Dive Center

“Corals, local corals, not as much growth on it, there was definitely some, because it was sunk in 1994.  But it’s covered with fish.  There were so many fish that you almost couldn’t see the wreck through the fish.”

AR-145 and all of the artificial reefs near Oregon Inlet are about the same size.  Each site is circular in nature with a diameter of a half nautical mile.

As for a timeline on the Bonner Bridge reef enhancements, construction to the replacement span is slated to start this March and take about 30 months to complete.  When it’s finished, the Bonner Bridge will be demolished and the material will be placed at the proposed reef sites.  Artificial Reef Coordinator Peters says that could begin as early as Fall of 2018. 

“Of course, that’s all very ballpark because as we know, Oregon Inlet is kind of a nasty beast sometimes, and this is all very weather dependent.”

The next step in the process is a public hearing on the proposal.  The meeting will take place February 8th at 6pm at the Dare County Administrative Building.

Credit NCDOT

“So this will be more of a public information session to let folks know that this is going to happen, we are enhancing the reefs up there, the material isn’t going to a landfill and sort of get people’s feelings and opinions on that.”

Peters says they are hoping to hear feedback as to which sites need the most enhancement.  Diver Pam Landrum says she’s excited about the project.

“I think it’s awesome, it helps the state’s economy, it helps the health of the ocean by creating more habitat for fish, so I think it’s a wonderful thing.”

It’s not the first time bridge pieces have been used to build a reef. In 2012, NCDOT donated 8,000 tons of material from the old Buddy Phillips Bridge to construct a 31-acre reef in the New River, between Jacksonville and Sneads Ferry.  If DOT had put the material into a landfill, it would have cost $75 a dump truck load, or $590,000. 

Credit NC Artificial Reef Program, NC Division of Marine Fisheries