Minimizing the environmental effects of our expanding population presents one of today’s most difficult challenges. How do we balance economic growth and environmental safety? The problem is particularly acute for booming coastal communities where waterfront development threatens critical marine environments, such as eelgrass meadows.

In the Pacific Northwest’s Puget Sound area, global positioning systems (GPS) and geographic information systems (GIS) are supplying a way for development and scientists to meet this challenge. The Washington State Department of Transportation (WSDoT) is relying on GPS and GIS to help protect critical nearshore marine habitats -- primarily eelgrass -- while the agency expands and improves its ferry system. The ferry system, which in 1995 transported more than 24 million passengers and vehicles across the Puget Sound, is consistently overloaded, resulting in two to three hour waits during the peak summer tourist season. WSDoT is addressing the overcrowding by constructing three new jumbo ferries, adding two more passenger-only boats, and expanding several terminals to accommodate the additional demand. However, WSDoT had to find a way to provide these improved services while also satisfying local residents’ desires to protect the natural environment they moved there to enjoy.

In fact, the State of Washington is so serious about environmental preservation, that in 1989 the Washington Department of Fish and Wildlife adopted a "no net loss" program for all marine habitats. Any waterfront construction project that might cause a loss of eelgrass must get a Hydraulic Project Approval. The ferry system expansion falls under this policy since it calls for the construction of new docks, which can threaten eelgrass by blocking the light the vegetation needs to survive.

Eelgrass mapping system

The first step in protecting eelgrass is mapping where it is. Marine Resources Consultants developed a creative, low-cost, real-time mapping solution to chart the proposed expansion areas. The consulting company’s solution utilizes a GPS-based underwater video graphic mapping system that is plotted in a Microsoft Excel. The basic idea is pretty simple, the crews’ helmsman monitors the underwater video camera on a TV screen in the boat. The GPS Receiver (manufactured by Trimble, Sunnyvale, CA) is connected to NMEA multiplexer, which is connected to a computer running Microsoft Excel and the WinWedge. WinWedge parses and filters the output from the GPS Receiver and directs it to the spreadsheet program.

The spreadsheet plots three data series. The first is the current longitude and latitude plotted in red with a black cross-hair in the middle, indicating the current vessel position. The other two data series consist of longitude and latitude coordinates for the vessel track line when eelgrass is present, indicated by a thick green line, or absent, indicated by a thin black line. The helmsman simply clicks on a eelgrass ON/OFF button embedded in the spreadsheet when eelgrass appears or disappears on his monitor. The result is a real-time plot of the area sampled that indicates where eelgrass is present.

The system has been used to help WSDoT expand its ferry system with no negative effects to the area eelgrass. The system is so impressive that on Earth Day in 1997, the US Department of Transportation awarded one of the terminal expansion projects the Distinguished Environmental Achievement Award for Research.

Before discovering WinWedge, data was collected by hand and charts were created on a PC back at the office. Users of the system noted that the process was significantly more time consuming and tedious before development of the real-time system.

Benefits

• 50% time reduction in data collection and analysis
• Accurate correlation of location and "eelgrass visibility" data from the GPS Receiver and video camera
• Real time remote data collection and immediate access to survey data

TAL Technologies, Inc.
2101 Brandywine Street,
Suite 102,
Philadelphia, PA 19130, USA
Tel: 800-722-6004
Tel: 215-496-0222
Fax: 215-496-0322

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