Kelp forest declines in Barkley Sound: lessons from the outer coast
Presentation Abstract
Brown algae in the order Laminariales (kelps), play fundamental roles in nearshore ecosystems around the world and drive coastal productivity. Kelps are optimally adapted to cool, temperate environments and have therefore experienced negative consequences in response to ocean warming in many parts of the world, including along the west coast of North America. In this study, we resurvey several observational datasets that were collected in Barkley Sound over the past 25 years to evaluate how recent broad-scale stressors have influenced kelp forests both above and below the tideline. Barkley Sound is the closest inlet of its size to the Salish Sea and shares all of the same kelp taxa. However, unlike the Salish Sea, Barkley Sound is largely protected and has very little industrial development. For this reason, it acts as an ideal study system to evaluate the impacts of environmental drivers, like temperature, on kelp forest resilience, in isolation from anthropogenic stressors. By comparing temporal changes in kelp abundance and distribution to site-level measures of wave action and temperature, we show that kelp forest resilience is linked to oceanic mixing which likely occurs at multiple scales. Summer water temperatures from the outer coast inwards vary by almost 2.5OC and higher wave exposure often makes sites locally cooler. We found that this complex thermal mosaic has likely influenced the responses of kelp forests to recent warm water anomalies, with site-specific declines observed in a range of kelp species.
Session Title
Session 2.2A: Kelp: Stressors, Trends, and Value (Part II)
Conference Track
Kelp & Seagrass
Conference Name
Salish Sea Ecosystem Conference (2020 : Online)
Document Type
Event
SSEC Identifier
2020_abstractID_4657
Start Date
22-4-2020 12:30 PM
End Date
22-4-2020 2:00 PM
Genre/Form
presentations (communicative events)
Subjects – Topical (LCSH)
Kelps--Climatic factors--British Columbia--Barkley Sound
Geographic Coverage
Salish Sea (B.C. and Wash.); Barkley Sound (B.C.)
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.
Type
Text
Language
English
Format
application/PDF
Kelp forest declines in Barkley Sound: lessons from the outer coast
Brown algae in the order Laminariales (kelps), play fundamental roles in nearshore ecosystems around the world and drive coastal productivity. Kelps are optimally adapted to cool, temperate environments and have therefore experienced negative consequences in response to ocean warming in many parts of the world, including along the west coast of North America. In this study, we resurvey several observational datasets that were collected in Barkley Sound over the past 25 years to evaluate how recent broad-scale stressors have influenced kelp forests both above and below the tideline. Barkley Sound is the closest inlet of its size to the Salish Sea and shares all of the same kelp taxa. However, unlike the Salish Sea, Barkley Sound is largely protected and has very little industrial development. For this reason, it acts as an ideal study system to evaluate the impacts of environmental drivers, like temperature, on kelp forest resilience, in isolation from anthropogenic stressors. By comparing temporal changes in kelp abundance and distribution to site-level measures of wave action and temperature, we show that kelp forest resilience is linked to oceanic mixing which likely occurs at multiple scales. Summer water temperatures from the outer coast inwards vary by almost 2.5OC and higher wave exposure often makes sites locally cooler. We found that this complex thermal mosaic has likely influenced the responses of kelp forests to recent warm water anomalies, with site-specific declines observed in a range of kelp species.
