CS17 Invasive Species
Date: Thursday, June 13, 2002
Time: 5:00:00 PM
Location: Sidney
 
KaldyJE, EPA- Pacific Coastal Ecology Branch, Newport, USA, kaldy.jim@epa.gov
 
COMPARISON OF ANNUAL PRODUCTION ECOLOGY OF NATIVE EELGRASS ZOSTERA MARINA AND THE NON-NATIVE DWARF EELGRASS Z. JAPONICA IN YAQUINA BAY, OREGON.
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When non-native plant species invade a system they often change patterns of primary production. I evaluate the contribution of the seagrass Zostera marina and it's non-native congener Z. japonica to primary production in Yaquina Bay. Few measurements of Z. japonica production exist in the literature and there are no comparative studies of annual production ecology. Biomass data from Yaquina Bay during summer 2001 suggests that although these seagrasses are morphologically distinct, they have similar standing stock between 190 and 230 gdw m-2. Additionally, leaf growth rates of Z. japonica (2.5-5.5 gdw m-2 d-1) are somewhat higher than Z. marina (1.5-3.5 gdw m-2 d-1). Consequently, on a per m2 basis, Z. japonica may contribute more fixed carbon to the system. However, because Z. japonica populations are small disjunct patches restricted to the upper intertidal margins, and Z. marina forms large meadows low in the intertidal, Z. marina probably contributes more carbon to the estuary.