The Distribution and Abundance of the Nonnative Eelgrass Zostera japonica in Oregon Estuaries

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The Distribution and Abundance of the Non-native
Eelgrass Zostera japonica in Oregon Estuaries
Chana Dudoit Mentor Dr. Sylvia Yamada Zoology
Dept.
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Zostera marina
Zostera japonica
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The Importance of Eelgrass Meadows in an Estuary
Nursery for juvenile fish
Foraging habitat
prey
Commercial industries
Nutrient cycling
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First Introduction
Seed oyster industry Used as packaging material
Washington State 1950s
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How is it transported?
Waves plants are carried in the
currents Birds seeds are eaten Ships plan
ts were used as packaging material
People accidental or purposefully
moved attached to boat motors
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Distribution of Eelgrass Pacific Northwest
Low Tide
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Distribution of Eelgrass Pacific Northwest
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Importance of mapping

• Comparative analysis of Z. japonica expansion
• Effect on habitat composition
• Change in species composition and abundance

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Species Composition
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Stabilize substrate
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Habitat degradation
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Study Sites
Netarts Bay South Slough National Estuarine
Research Reserve (SSNERR) Bandon Marsh National
Wildlife Refuge
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1-24
25-49
50-74
75-100
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Penetrometer measures the density of a substrate
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(No Transcript)
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Netarts Bay
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Percent Cover of Z. japonica in Netarts Bay 2005
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South Slough National Estuarine Research Reserve
(SSNERR)
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Percent Cover of Z. japonica in South Slough
National Estuarine Research Reserve
1984
2004
2005
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Bandon Marsh National Wildlife Refuge
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Percent Cover of Z. japonica in Bandon Marsh
National Wildlife Refuge, 2005
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Discussion

• Developing technologies
• Aerial photographic surveys using
• true color (TC) film
• false-color near-infrared (color infrared, CIR)
  film

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Acknowledgments
Dr. Sylvia Yamada, Zoology Dept. OSU Dr. Samuel
Chan, Oregon Sea Grant, OSU Dr. David Young, EPA
Newport Derek Sowers, SSNERR Scott Growth,
DFW Chelsea Dudoit, volunteer