Author Identifier (ORCID)
Simone Strydom: https://orcid.org/0000-0002-0080-483X
Abstract
Marine heatwaves, and other extreme climatic events, are driving mass mortality of habitat-forming species and substantial ecological change worldwide. However, habitat fragmentation is rarely considered despite its role in structuring seascapes and potential to exacerbate the negative impacts of habitat loss. Here, we quantify fragmentation of globally significant seagrass meadows within the Shark Bay World Heritage Area before and after an unprecedented marine heatwave impacting the Western Australian coastline over the austral summer of 2010/11. We use a spatial pattern index to quantify seagrass fragmentation from satellite-derived habitat maps (2002, 2010, 2014 and 2016), assess potential predictors of fragmentation and investigate seascape dynamics defined by relationships between seagrass fragmentation and cover change. Our spatiotemporal analysis illustrates widespread fragmentation of seagrass following the marine heatwave, contributing to a dramatic alteration of seascape structure across the World Heritage Area. Fragmentation immediately following the marine heatwave coincided with widespread seagrass loss and was best explained by interactions between a heat stress metric (i.e. degree heating weeks) and depth. Based on the relationship between fragmentation and seagrass cover change, we revealed near-ubiquitous fragmentation from 2014 to 2016 represents a mixture of long-term seagrass degradation and evidence of early, patchy recovery. Fragmentation effects are expected to compound the ecological impacts of seagrass mortality following the marine heatwave and prolong recovery. As sea temperatures and the threat of marine heatwaves continue to rise globally, our results highlight the importance of considering fragmentation effects alongside the negative impacts of habitat loss. Our seascape dynamic framework provides a novel approach to define the response of habitat-forming species to disturbances, including marine heatwaves, that integrates the processes of fragmentation and cover change. This framework provides the opportunity to consider these important processes across a range of threatened ecosystems and identify areas of vulnerability, stability and recovery.
Document Type
Journal Article
Date of Publication
1-1-2025
Publication Title
Remote Sensing in Ecology and Conservation
Publisher
Wiley
School
Centre for Marine Ecosystems Research / School of Science
RAS ID
88036
Funders
Pawsey Supercomputing Research Centre / Australian Government / Government of Western Australia / The Jock Clough Marine Foundation / The Holsworth Wildlife Research Endowment / University of Western Australia / Pew Charitable Trusts / Australian Research Council
Grant Number
ARC Number : DP210103091
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License
Comments
Taylor, M. D., Strydom, S., Fraser, M. W., Sequeira, A. M. M., & Kendrick, G. A. (2025). Breaking down seagrass fragmentation in a marine heatwave impacted World Heritage Area. Remote Sensing in Ecology and Conservation. Advance online publication. https://doi.org/10.1002/rse2.70032