Petroleum industry's use of seagrass restoration as mitigation for construction and as a potential cleanup tool

摘要

The Laguna Madre in Corpus Christi,Texas has a great deal of petroleum and natural gas activity while housing a national seashore.The area is a flyway for a wide array of bird species,as well as heavily fished.Historically,the laguna had a series of infrastructure modifications,gas and oil rigs,and real estate development.In the process of placing a drilling rig,a winter storm blew the vessel with the rig off a narrow channel.To remove the vessel,other vessels had to be called.A 35-acre accident occurred.In mitigation,75 acres of the seagrass Halodule wrightii was planted in three areas:(1)a 15-acre dredge island where a portion of the island was scraped down from uplandspoil deposit to -2 ft mlw;(2)a mile-long channel where seagrasses were restored from -7 to 10 ft mlw to -3 to ft mlw;and(3)a persistently barren site for decades(scraped by another petroleum company's vessel)was restored in the shallows while holes were filled in and seagrass planted on top.The fill throughout was from the scraping from the dredge islands.The fill was transmitted several miles by a new device.Planting of Halodule plugs proceeded from March to July 1999.Within 3 months,the shallow sites had been covered with the restored Halodule.Endangered species of roseate spoonbills,brown pelicans,great white herons and other wading and fishing birds were regularly feeding at two sites.The deeper sites had heavy fish populations return to the area,fished by man,seagulls and pelicans.Despite a direct hit by Hurricane Bret in 1999,lateral growth at all depths was deemed governmentally satisfactory.This same procedure with seagrasses is recommended for after-effects of estuarine oil spill cleanup,and mitigation banks of seagrasses are recommended for construction or operations mitigation.