Presentation Abstract

Widely regarded as critical marine habitat, seagrass provides ecologically and economically valuable services in coastal areas worldwide. Eelgrass (Zostera marina) is one of five seagrass species native to the Pacific Northwest and is threatened by outbreaks of the marine protist Labyrinthula zosterae, the causative agent of seagrass wasting disease. Infection from L. zosterae causes necrotic lesions, limiting growth and compromising the health of eelgrass beds. To determine levels of wasting disease in subtidal eelgrass beds across a broad latitudinal gradient, we measured and compared disease prevalence and severity in 5 subtidal eelgrass beds in Puget Sound, 5 in the San Juan Islands, 4 on Calvert Island, British Columbia, and 4 in south eastern Alaska. Disease prevalence, the proportion of diseased blades to health blades, was highest in Puget Sound, and steadily decreased in sites further north. Severity, the proportion of diseased tissue to healthy tissue on infected blades, also varied between sites and geographic regions. To determine potential environmental drivers of disease across broad spatial scales, we also measured site characteristics: density, canopy height, water temperature, and salinity. Understanding broad-scale patterns of disease and environmental drivers of wasting disease outbreaks can inform key decisions regarding eelgrass conservation within and beyond the Salish Sea.

Session Title

Seagrass Cross-border Connections: Status and Trends

Keywords

Eelgrass, Seagrass, Seagrass wasting disease

Conference Track

SSE4: Ecosystem Management, Policy, and Protection

Conference Name

Salish Sea Ecosystem Conference (Seattle, WA : 2018)

Document Type

Event

SSEC Identifier

SSE4-111

Start Date

5-4-2018 10:00 AM

End Date

5-4-2018 10:15 AM

Type of Presentation

Oral

Contributing Repository

Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.

Geographic Coverage

Salish Sea (B.C. and Wash.)

Rights

This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.

Type

text

Language

English

Format

application/pdf

Share

COinS
 
Apr 5th, 10:00 AM Apr 5th, 10:15 AM

Latitudinal variation in seagrass wasting disease from Puget Sound to Alaska

Widely regarded as critical marine habitat, seagrass provides ecologically and economically valuable services in coastal areas worldwide. Eelgrass (Zostera marina) is one of five seagrass species native to the Pacific Northwest and is threatened by outbreaks of the marine protist Labyrinthula zosterae, the causative agent of seagrass wasting disease. Infection from L. zosterae causes necrotic lesions, limiting growth and compromising the health of eelgrass beds. To determine levels of wasting disease in subtidal eelgrass beds across a broad latitudinal gradient, we measured and compared disease prevalence and severity in 5 subtidal eelgrass beds in Puget Sound, 5 in the San Juan Islands, 4 on Calvert Island, British Columbia, and 4 in south eastern Alaska. Disease prevalence, the proportion of diseased blades to health blades, was highest in Puget Sound, and steadily decreased in sites further north. Severity, the proportion of diseased tissue to healthy tissue on infected blades, also varied between sites and geographic regions. To determine potential environmental drivers of disease across broad spatial scales, we also measured site characteristics: density, canopy height, water temperature, and salinity. Understanding broad-scale patterns of disease and environmental drivers of wasting disease outbreaks can inform key decisions regarding eelgrass conservation within and beyond the Salish Sea.