40 oyster reefs placed along Gandy's Beach in New Jersey to support live oysters and cut storm-wave

The project included 27 concrete “oyster castle” breakwaters and 13 shell-bag reefs. In an unusual effort to protect an eroding stretch of New Jersey’s Delaware Bay shoreline, 40 constructed oyster reefs were installed at Gandy’s Beach Preserve between 2015 and 2016.A new study published in Frontiers in Marine Science examined the project along with other nature-based coastal protection measures used in New Jersey. Researchers found that while such projects can help restore habitats, their ability to protect coastlines often requires continued maintenance.The manmade reefs at Gandy’s Beach quickly attracted oysters. In 2016 and 2017, researchers recorded average densities of more than 800 live oysters per square metre.The reefs also reduced waves during storms when they were above water or only slightly submerged. During four nor’easters in 2018, wave height fell by 41% across the reefs and by as much as 51% between the seaward and most landward monitoring points.However, the protection weakened when the reefs were fully underwater. Over seven years, the reef groups also lost about 20 centimetres of elevation on average, while the site recorded a net loss of 558 square metres of ve...