Document Type
Journal Article
Publication Title
Marine Ecology Progress Series
Publisher
Inter-Research
School
School of Science
RAS ID
56680
Funders
Australian Research Council / Australian Government Research Training Program (RTP) Scholarship
Grant Number
ARC Number : DP170100023
Grant Link
http://purl.org/au-research/grants/arc/DP170100023
Abstract
Over the past decades, ocean temperatures have been steadily increasing and are projected to continue to do so, stressing many temperate marine organisms. Changing temperatures do not affect ecosystems in isolation, but interact with many other factors in shaping ecological communities. We investigated the changes over 2 decades in subtidal temperate seaweed communities over a wave exposure gradient in Western Australia, a global warming hotspot. We found higher diversity in the seaweed community and a higher proportion of biomass of species with a warm affinity (expressed as the tropicalization index: TI) over time. There was no decline in biomass of the dominant habitat-forming kelp Ecklonia radiata on low wave exposure reefs, while it was patchier and comprised a lower proportion of the total seaweed biomass on the medium and high wave exposure reefs. Furthermore, the presence of E. radiata was disproportionally associated with low abundances of seaweeds with warm affinity. The increasing patchiness of E. radiata likely provided a competitive release for other seaweeds, and the increase in abundance of Scytothalia dorycarpa likely provided a compensatory effect which resulted in a lower than expected TI. We found no indication of an ameliorating effect by wave exposure, and conclude that the patch dynamics driven by wave exposure are more likely exacerbated by increasing ocean temperatures on subtidal temperate reefs. If this continues, the reduction in E. radiata and increase in warm affiliated seaweeds will result in a more diverse seaweed community, but one with a lower standing biomass.
DOI
10.3354/meps13989
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Comments
Mulders, Y., Mattio, L., Phillips, J. C., Lavery, P. S., Kendrick, G. A., & Wernberg, T. (2022). Patch dynamics driven by wave exposure in subtidal temperate seaweeds are exacerbated by warming oceans. Marine Ecology Progress Series, 685, 85-95. https://doi.org/10.3354/meps13989