Presentation Abstract

Kelp beds are marine sanctuaries, providing some of the most productive ecosystems on the planet and serving as critical habitat and refuge for many species, including juvenile salmon. Rising ocean temperature associated with climate change is a major stressor contributing to declines of kelp forests worldwide. In the Salish Sea, we identified bull kelp (Nereocystis leutkeana) populations growing under two different temperature regimes. Since 2011, kelp growing in the central Strait of Georgia has been exposed to sea surface temperatures (SSTs) of 15-21 °C in the summer months, which is 5-6 °C warmer than temperatures in the Strait of Juan De Fuca. To assess the effects of high summer SSTs, populations growing at a warm and a cold site (Stanley Park and French Beach respectively) were sampled in the summer and fall of 2017. Warmer summer SSTs at Stanley Park correlated with significant declines in spore production, indicating negative effects on the reproductive capacity of that population. Growth and development of healthy spores from either population was reduced when incubated in the lab at temperatures above ~ 17 °C and temperatures of ~ 20 °C resulted in mortality of nearly all spores. Analyses of stress levels in spores exposed to different temperatures, based on the production of reactive oxygen species, is now underway. This research continues to provide crucial data needed for habitat restoration efforts as they will allow for the selection of stress-resilient kelp stocks that are better adapted for survival in warmer oceans.

Session Title

Kelp Distribution and Recovery Strategies in the Salish Sea: Part II

Keywords

Kelp, Resilience, Temperature, Tolerance, Nereocystis

Conference Track

SSE1: Habitat Restoration and Protection

Conference Name

Salish Sea Ecosystem Conference (Seattle, WA : 2018)

Document Type

Event

SSEC Identifier

SSE1-175

Start Date

6-4-2018 11:00 AM

End Date

6-4-2018 11:15 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

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Apr 6th, 11:00 AM Apr 6th, 11:15 AM

Effects of warm ocean temperatures on bull kelp forests in the Salish Sea

Kelp beds are marine sanctuaries, providing some of the most productive ecosystems on the planet and serving as critical habitat and refuge for many species, including juvenile salmon. Rising ocean temperature associated with climate change is a major stressor contributing to declines of kelp forests worldwide. In the Salish Sea, we identified bull kelp (Nereocystis leutkeana) populations growing under two different temperature regimes. Since 2011, kelp growing in the central Strait of Georgia has been exposed to sea surface temperatures (SSTs) of 15-21 °C in the summer months, which is 5-6 °C warmer than temperatures in the Strait of Juan De Fuca. To assess the effects of high summer SSTs, populations growing at a warm and a cold site (Stanley Park and French Beach respectively) were sampled in the summer and fall of 2017. Warmer summer SSTs at Stanley Park correlated with significant declines in spore production, indicating negative effects on the reproductive capacity of that population. Growth and development of healthy spores from either population was reduced when incubated in the lab at temperatures above ~ 17 °C and temperatures of ~ 20 °C resulted in mortality of nearly all spores. Analyses of stress levels in spores exposed to different temperatures, based on the production of reactive oxygen species, is now underway. This research continues to provide crucial data needed for habitat restoration efforts as they will allow for the selection of stress-resilient kelp stocks that are better adapted for survival in warmer oceans.