Gaining ground: survival of native estuarine fauna exposed to recycled glass sand, a potential material for coastal restoration

Abstract Objectives The aim of this research is to develop an understanding of the potential for using recycled glass sand as a resource for restoring Louisiana's coastline by testing the effects of exposure of native estuarine fauna to recycled glass sand and other sand treatments in a laboratory environment. Methods Five species native to Louisiana estuaries were exposed to six different sediment treatments, including two recycled glass sand treatments, for 30–38 days over a period from June 2022 to January 2023. The tested species were Atlantic croaker ( Micropogonias undulatus ), Gulf Killifish ( Fundulus grandis ), Blue Crab ( Callinectes sapidus ), White Barnacle ( Semibalanus balanoides ), and Eastern Oyster ( Crassostrea virginica ). The six treatments were: Mississippi river dredge (natural sand); Quickcrete Play Sand; Fairmount‐Santrol Aquaquartz; Glass Half Full (GHF) L5 fine grain recycled glass sand, a custom‐made mix of 50% Mississippi river dredge, 25% each of two coarse recycled glass sands (GHF L3 and GHF L4); and a control treatment of no sediment. Each animal was housed individually or in pairs based on species, and received feeding and wellness checks daily. After approximately 30 days, all survivors were euthanized and survivorship for each group was calculated. Results The results of the exposure experiments varied slightly among species, but overall survivorship was high and did not differ significantly among treatments. We observed little to no lethal effects of exposure of native estuarine fauna to recycled glass sand, or any of the other sand treatments we tested. Conclusion Our results suggest that recycled glass sand can be used in coastal restoration.