Seaweed responses to climate change: predictions, observations, and knowledge gaps
Presentation Abstract
Kelps and other macroalgae in the Salish Sea are sentinel species for detecting the effects of climate change on marine ecosystems. However, the connections between changes in climate and changes in the distribution and abundance of benthic algae are complex. Warming, particularly in the intertidal where high temperatures can be stressful, is generally expected to result in seaweed mortality and contraction of species’ upper limits. Detailed time-series data support this contention; the upper limit of an intertidal turf contracts downshore during rare heat waves. Historical data from the Strait of Juan de Fuca suggest that this is true for intertidal kelps as well, as the upper limits of several kelp species have shifted downshore since the 1950s. However, surveys of other seaweeds at the same sites did not reveal coherent patterns in non-kelp species over the same time period. Into the future, patterns of seaweed distribution and abundance will be driven by multiple stressors including temperature and ocean acidification, and the novel combinations of these stressors may produce unexpected outcomes. Furthermore, important climate-driven changes in herbivore populations will have far-reaching effects on seaweeds. At this stage, we have accumulated a wealth of (usually) single-factor / single-species laboratory studies that identify some potential leverage points for change, and some historical data confirming ongoing changes in the field. Future work must focus on comprehensive experiments that can mimic realistic combinations of climate change stressors in communities that contain important producers and consumers, and provide better links between what is observed in the laboratory and in the field.
Session Title
Session S-02E: Kelp Trends
Conference Track
Habitat
Conference Name
Salish Sea Ecosystem Conference (2014 : Seattle, Wash.)
Document Type
Event
Start Date
30-4-2014 1:30 PM
End Date
30-4-2014 3:00 PM
Location
Room 613-614
Genre/Form
conference proceedings; presentations (communicative events)
Contributing Repository
Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.
Subjects – Topical (LCSH)
Marine algae--Climatic factors--Salish Sea (B.C. and Wash.); Marine algae--Ecology--Salish Sea (B.C. and Wash.)
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
Seaweed responses to climate change: predictions, observations, and knowledge gaps
Room 613-614
Kelps and other macroalgae in the Salish Sea are sentinel species for detecting the effects of climate change on marine ecosystems. However, the connections between changes in climate and changes in the distribution and abundance of benthic algae are complex. Warming, particularly in the intertidal where high temperatures can be stressful, is generally expected to result in seaweed mortality and contraction of species’ upper limits. Detailed time-series data support this contention; the upper limit of an intertidal turf contracts downshore during rare heat waves. Historical data from the Strait of Juan de Fuca suggest that this is true for intertidal kelps as well, as the upper limits of several kelp species have shifted downshore since the 1950s. However, surveys of other seaweeds at the same sites did not reveal coherent patterns in non-kelp species over the same time period. Into the future, patterns of seaweed distribution and abundance will be driven by multiple stressors including temperature and ocean acidification, and the novel combinations of these stressors may produce unexpected outcomes. Furthermore, important climate-driven changes in herbivore populations will have far-reaching effects on seaweeds. At this stage, we have accumulated a wealth of (usually) single-factor / single-species laboratory studies that identify some potential leverage points for change, and some historical data confirming ongoing changes in the field. Future work must focus on comprehensive experiments that can mimic realistic combinations of climate change stressors in communities that contain important producers and consumers, and provide better links between what is observed in the laboratory and in the field.
