The use of oyster reef restoration as a method of erosion control

摘要

Historically, oyster reefs have enhanced Louisiana's coastal ecosystem and provided a lucrative industry for many Louisianans. Although there are extensive reefs in coastal Louisiana, many areas have been harvested without replenishment. Areas now devoid of oyster reefs, such as Vermilion Bay, are consequently experiencing serious erosion problems. Recently, interest in oyster reef restoration as a solution to coastal erosion has surfaced. The design of a structure that would aid in oyster reef restoration in the shape of a submerged breakwater was designed, built, and deployed in summer 2002. This structure, termed an "oysterbreak," is designed to stimulate the growth of biologic structures in a wave dissipating shape. In the same way native oyster reefs can form immense structures that protect shorelines and coastal communities from storms, this structure would provide the same function. One principle behind the oysterbreak is to provide a support structure with maximum surface area for oyster establishment while maintaining its lightweight characteristics for deployment. A series of experiments were conducted to evaluate the oysterbreak's ability to initiate oyster growth and exude erosion abatement characteristics. A prototype structure was constructed and placed in Grand Isle, Louisiana, for a period of one year. Spatial patterns of oysters were examined on different man-made materials flow. Physical model experiments were carried out to determine growth and design effects on wave dissipation characteristics of the oysterbreak. Through these experiments, significant advancements have been made toward using these types of structures as tools for reducing coastal erosion.