Wendy Fister: New scientific approaches tackle spartina infestation on B.C. coast

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      By Wendy Fister

      Spartina anglica, an aggressive aquatic grass, was introduced to the west coast near California many years ago and has been gradually creeping north ever since. Leaving havoc in its wake, it converts coastal mud flat areas to monoculture stands, increases sediment deposits, modifies drainage patterns, and contributes to the loss of significant fish and wildlife habitat.

      Since the infestation was first recognized, the B.C. Spartina Working Group, a consortium of conservation organizations and government agencies, has led removal and control efforts, particularly in two high priority areas in Delta: Brunswick Point and Boundary Bay.

      As one of the lead partners, Ducks Unlimited Canada has always relied on science to guide our conservation efforts, and the removal of spartina is no exception. Along with our partners, we have been sharing knowledge and exchanging best practices. These collaborative efforts are yielding some unique scientific approaches that are guiding conservation planning.

      In 2006, several U.S. and Canadian organizations initiated a collaborative drift card study to assess the potential spread of spartina in the Strait of Georgia and Puget Sound areas. More than 7,000 drift cards were released from six spartina locations to simulate the current’s effect on the potential movement of seeds and rhizomes. From the start, the public’s participation was critical. Each card included a 1-800 number and the Community Mapping Network’s Web site address, encouraging finders to report the cards’ final destinations.

      By 2008, approximately 2,900 cards had been reported at 1,800 sites. The maximum distance any reported card had travelled was 913 kilometres (in Alaska), with most of the reported cards originating from a central release point in the Strait of Georgia. Findings from this study are being used to predict which coastline locations are potential spartina hot zones and should receive more monitoring and focused plant removal efforts in the future.

      Sometimes the KISS (keep it simple, stupid) principle provides a good solution to a complicated problem. Removing spartina from difficult-to-reach areas has posed a significant problem in the past. In 2008, the Washington State Department of Agriculture joined Ducks Unlimited Canada at Brunswick Point to demonstrate geotextile covering techniques. Based on WSDA’s experience, covering and shading spartina prevents the plant’s natural photosynthesis processes from occurring. Researchers found that it takes about two years to destroy the spartina plant and this technique has far less impact on mud flat areas than current excavation techniques.

      The geotextile fabric was cut to cover each spartina patch, and four different techniques were used to anchor the fabric to the ground: plastic stakes, steel rods, steel pins, and burying the edge. In total, eight test plots were created to represent both low and high intertidal zones and will be monitored over the next two years to determine which method is most effective for the Fraser River delta.

      Imagine how fun it would be to float across the mud flats and call it work. That’s what biologists from Ducks Unlimited Canada did during a demonstration by the WSDA on its use of an airboat to efficiently and effectively monitor large spartina patches that are difficult to access on foot. In some areas—like ecologically rich Brunswick Point, which has a very sensitive biofilm that provides food for shorebirds—the airboats have been effective in covering the area while reducing impacts on the ecosystem.

      The B.C. Spartina Working Group continues to explore different methods for early detection, removal, and outreach to deal with spartina’s coastal attack. However, strapped by limited financial and human resources, more help is required to tackle this year’s growing crop.

      Wendy Fister is a marketing and communications specialist for Ducks Unlimited Canada.

      If you are interested in volunteering for removal efforts at Boundary Bay and Roberts Bank, you can e-mail du_surrey@ducks.ca for more information. Removal efforts will take place from July 6 to 10 and July 20 to 24.