{"id":3543,"date":"2022-03-09T18:00:00","date_gmt":"2022-03-10T00:00:00","guid":{"rendered":"https:\/\/www.aapaseaports.com\/?p=3543"},"modified":"2022-03-24T12:48:12","modified_gmt":"2022-03-24T17:48:12","slug":"dredging-striking-a-balance","status":"publish","type":"post","link":"https:\/\/www.aapaseaports.com\/index.php\/2022\/03\/09\/dredging-striking-a-balance\/","title":{"rendered":"Dredging: Striking a Balance"},"content":{"rendered":"
\n
\n Feature<\/div>\n
\n Improving and Minimizing the Toll on Wildlife Habitat and the Environment, While Also Deepening the Waterways for Commerce<\/div>\n
\n By Nick Fortuna<\/span><\/div>\n
\n \"maxx-studio\"
\n MAXX-STUDIO\/SHUTTERSTOCK.COM<\/a> \u2022 RICH CAREY\/SHUTTERSTOCK.COM<\/a><\/span>
\n<\/figcaption><\/figure>\n

E<\/strong><\/span>ndangered sea turtle species rarely visit the beaches of South Florida to nest during the cold winter months, which is one of the reasons the Port of Palm Beach finds they are also good months for some serious sand-moving. Plus, the sights and sounds of workers assembling a pipeline and operating machinery on the beach are usually enough to keep sea turtles and seabirds from nesting nearby.<\/p>\n

But sometimes, wild animals just can\u2019t take a hint, so the environmental consultants get up early and dutifully make their rounds.<\/p>\n

Each morning during the project, environmental consultants will drive all-terrain vehicles up and down those beaches looking for turtle tracks. If nests are found, that area will be marked off with stakes and orange flagging so that sand isn\u2019t deposited there, or the nests will be relocated. Any eggs present will be moved along with the nests or taken to a sea-turtle hatchery. In time, the young turtles may be released back into the wild.<\/p>\n

“They\u2019ll be there every morning throughout this project,” said Port Engineer Ronald Coddington.<\/p>\n

The dredging project was scheduled to start in January and last for three months, moving about 400,000 cubic yards of sand. Dredging material from the settling basins and harbor channel would be transported by hopper dredge and pumped onto the beaches of the town of Palm Beach, reversing years of erosion \u2013 but not at the cost of the local wildlife and environment.<\/p>\n

Jene Adler, business development manager and environmental services project coordinator for Texas-based Orion Marine Group, said it\u2019s rare for a sea turtle to be sucked up during hydraulic dredging. Turtles are less likely to swim in the deep waters where dredging takes place at ports, and suction pipes are equipped with screens or other excluder devices to prevent such an occurrence.<\/p>\n

But when it does happen, it\u2019s immediately reported to the Corps, as mandated by federal law. Turtles sometimes survive the ordeal, emerging with a bruised shell or missing a limb, and are swiftly transported to a rehabilitation facility, Adler said.<\/p>\n

“The Corps of Engineers is very much on top of that,” she said. “There are lots of protocols in place to keep that from happening, so it\u2019s rare, but it does happen.”<\/p>\n

Monitoring seabird and sea turtle activity is just one of the ways AAPA members are keeping the environment top of mind during improvement projects. Under the watchful eye of environmental agencies and the U.S. Army Corps of Engineers, which supervises most of the dredging activity in the United States, ports and dredging companies are working hard to be good stewards of the environment.<\/p>\n

Keeping the Impact Contained<\/h2>\n

Since dredging at ports typically is performed in deeper waters, many projects don\u2019t take place amid fisheries or parts of the seafloor inhabited by seagrass or coral, which need clear water and sunlight to thrive, according to William H. Hanson, senior vice president for government relations and business development at Great Lakes Dredge and Dock Co.<\/p>\n

Hanson\u2019s company, the nation\u2019s largest provider of dredging services, moved its headquarters to Houston in 2020 from Oak Brook, Ill. Over its 132-year history, GLDD has performed dredging work at just about every major port in the country.<\/p>\n

Hanson said a more common issue is that turbidity from dredging operations may deposit sediment on top of seagrass, depriving it of sunlight. Since port channels must be widened as they\u2019re deepened, nearby patches of seagrass and coral may be adversely impacted by turbidity plumes, especially during mechanical dredging operations.<\/p>\n

To mitigate that risk, contractors may use a full-depth turbidity curtain, typically made from reinforced, impermeable PVC fabric. The turbidity barrier stretches from the water\u2019s surface to the seafloor to contain the silt and sediment stirred up by dredging.<\/p>\n

Transplanting Seagrass and Coral<\/h2>\n

Manatees, a threatened species of marine mammal, rely on seagrass for food, so when it\u2019s found near a proposed dredging site, it\u2019s often replanted in another area. During PortMiami\u2019s major deepening project that was completed in 2015, CSA Ocean Sciences Inc. transplanted more than 115,000 seagrass plants into a newly filled dredge hole north of the Julia Tuttle Causeway in Miami.<\/p>\n

CSA was part of the GLDD team that was awarded the primary contract for the Miami project by the Corps. Divers meticulously planted 29,000 bare-root “planting units” by hand to ensure that the growing tips of the plant were buried to the appropriate depth below the sediment surface. To provide passive fertilization through the introduction of coastal bird feces, more than 1,150 bird roosting stakes were installed within the 17-acre mitigation site, according to CSA.<\/p>\n