RIASSUNTO
Abstract
Four years after completing two exploration projects in the Sabine National Wildlife Refuge, Vastar Resources, Inc., recently conducted an evaluation of its wetlands restoration and enhancement efforts in the refuge. Close inspection of the project areas indicates that the company's restoration efforts were successful in promoting a healthy and vibrant wetland ecosystem, supporting a plant community composition and percent surficial coverage approximate to that of undisturbed marsh.
In this paper, the authors discuss the various techniques utilized in access road and drill site restoration that revitalized this sensitive wetland environment. Techniques discussed include:
Maintenance of pre-existing water flows;
Systematic selection and use of native soils to construct road dumps and ring levees;
Protection of existing vegetative root networks;
Improved indigenous seed bed preparation;
Creation and use of ecotones to promote habitat diversity and increased wildlife production; and
Conversion of roadbeds and ring levees to nesting and resting habitat.
These techniques were employed as part of an ecosystem approach to wetlands resource management, involving the restoration of the multiple values and functional attributes of this unique ecological system.
Introduction
Coastal wetland environments pose perhaps one of the most sensitive, diverse, and challenging environments in which the oil & gas industry operates. Recognizing these challenges, industry continues to develop and implement innovative and environmentally responsible techniques in an effort to minimize the potential effects of oil & gas exploration and production operations on the surrounding environment.1,2,3 Cooperation between industry, the natural resource trustees, and the public is paramount in balancing the need to protect our coastal wetland environments with the equally compelling need for the exploration and development of the natural resources they contain.
In 1993 and 1994, Vastar pursued an exploration prospect, known as ""Black Bayou,"" in the Sabine National Wildlife Refuge, Cameron Parish, Louisiana (See Figure 1). Approximately 125,000 acres in size, the refuge is the largest in the Gulf Coast region, and serves as a major wintering ground for waterfowl, shorebirds and wading birds. The refuge possesses unquestionable value as essential habitat for fish and shellfish (nursery and spawning grounds), for migratory waterfowl and avian species, and for furbearers and other wildlife.4
Vastar's Black Bayou activities were designed to not only minimize environmental impacts in the refuge, but also to restore and enhance the natural diversity of the ecosystem in the immediate area of the drill locations and access road system. The project team worked closely with the U.S. Fish and Wildlife Service personnel at the refuge, as well as local, state, and federal agencies, during the planning phase of the project to establish the construction, operational, and restoration techniques that would be used to accomplish this goal. In an earlier SPE paper, the authors discussed some of the progressive construction and operational techniques employed on the project to minimize the impacts from construction and drilling operations.3 In this paper, the authors discuss some of the techniques used during the project which enabled the project team to successfully restore and enhance the refuge environment. The techniques utilized include maintenance of existing wetlands hydrology, use of native fill material to construct road dumps and ring levees, preservation of existing root networks, improved seed bed preparation, creation of nesting/resting habitat, and the creation of ecotones.