Long-term intertidal community change following mass mortality of Pisaster ochraceus, a keystone marine predator
Abstract/Contents
- Abstract
- Beginning in 2013, a Sea Star Wasting Disease epidemic caused a mass mortality event for the ochre sea star (Pisaster ochraceus) and several other sea star species across their entire range of distribution in the California Current region. Because Pisaster ochraceus is a keystone species in rocky intertidal communities and has been shown to control California mussel (Mytilus californianus) populations and prevent their competitive dominance under several settings, thereby maintaining intertidal community diversity, sudden sea star population declines are expected to cause cascading changes on the community. This study tests this prediction and investigates how the natural removal of keystone predation affects the rocky intertidal community in the long term. Previous studies conducted at Hopkins Marine Station, in Monterey Bay, California, in 2014 and 2015 found a limited and spatially heterogeneous expansion of M. californianus following the sea star demise. Field surveys of 18 mussel plots at two sites at Hopkins Marine Station conducted three times a year between 2014 and 2021 show that mussel cover has been increasing since 2014, when there was a peak in mussel recruitment in the area, and that the lower limit of mussel beds has been shifting to lower tidal heights, supporting the hypothesized mussel expansion following predator mass mortality. However, long-term monitoring of the P. ochraceus population at Hopkins Marine Station shows that sea star abundance has been declining since long before 2013. It is therefore likely that changes in M. californianus abundance and distribution are driven by other factors, such as recruitment variability and extreme events in addition to predation pressure. As more mass mortality events are expected under warming conditions in the coming decades, the results of this study, and of future research addressing the impact of multiple stressors on intertidal communities can inform predictions about how the community will change when these events occur.
Description
| Type of resource | text |
|---|---|
| Date modified | December 5, 2022 |
| Publication date | May 5, 2022; May 2022 |
Creators/Contributors
| Author | Chapuis, Micaela |
|---|---|
| Thesis advisor | Micheli, Fiorenza |
| Thesis advisor | Fukami, Tadashi |
| Thesis advisor | Crowder, Larry |
| Degree granting institution | Stanford University, Department of Biology |
Subjects
| Subject | Biology |
|---|---|
| Subject | Keystone species |
| Subject | Pisaster ochraceus |
| Subject | Mytilus californianus |
| Subject | Mussels |
| Subject | Sea Star Wasting Disease |
| Subject | Marine ecology |
| Subject | Predation |
| Subject | Recruitment |
| Genre | Text |
| Genre | Thesis |
Bibliographic information
Access conditions
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 4.0 International license (CC BY-NC).
Preferred citation
- Preferred citation
- Chapuis, Micaela, and Micheli, Fiorenza (2022). Long-term intertidal community change following mass mortality of Pisaster ochraceus, a keystone marine predator. Stanford Digital Repository. Available at https://purl.stanford.edu/xn304xh4597
Collection
Undergraduate Theses, Department of Biology, 2021-2022
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- Contact
- mchapuis@stanford.edu
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