Long‐term community shifts driven by local extinction of an iconic foundation species following an extreme marine heatwave

Abstract

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Global taxonomic and functional patterns in invertebrate assemblages from rocky-intertidal mussel beds

“…First, unstudied foundation species could be expected to host communities similar in function to those hosted by the same kind of foundation species that has been studied elsewhere. Second, if foundation species continue to be lost because of anthropogenic factors 5 – 8 , this knowledge will aid restoration efforts that attempt to recreate specific functions lost in an ecosystem.…”

“…Foundation species can be primary producers such as trees and seaweeds or animals such as bivalves and corals 1 – 4 . Recognition of their ecological relevance especially given recent losses due to anthropogenic factors 5 – 8 is fueling the need to understand what kinds of associated communities are hosted by foundation species. This article presents the first global analysis of the taxonomic and functional diversity of invertebrate assemblages living in rocky-intertidal mussel beds.…”

Facilitation of animals is stronger during summer marine heatwaves and around morphologically complex foundation species

“…This has been shown for seaweed foundation species after simulated (Nepper‐Davidsen et al, 2020 ) and real (Wernberg et al, 2018 ) MHWs, but not yet for marine epifauna. Importantly, negative impacts from MHWs on seaweed foundation species are likely to also cause indirect lag effect on epifauna, as their critical habitat is lost and they become more susceptible to predation or environmental stress (Doney et al, 2012 ; Montie & Thomsen, 2023 ; Schiel et al, 2021 ; Smale et al, 2019 ).…”

“…Zip lock bags with mimics and epifauna were transported to the laboratory and rinsed over a 250 μm sieve. Unfortunately we were unable to identify epifauna to species level but instead recorded higher taxonomic units (like class or family) as well as lower level morphologically determined ‘operational taxonomic units’ (OTUs; morphotypes, as in Montie & Thomsen, 2023 , Thomsen et al, 2022 ). Morphotypes were identified within the classes hexanauplia, nematoda, polychaeta, and gastropoda.…”

Facilitation cascades across space: Monitoring estuarine foundation species from satellites to the microscope

“…Here we extend and build on this study by: (1) analyzing community structures and diversity in the facilitation cascade (including microscopic animals); (2) analyzing photos, drones, and satellite images to detect and quantify Ulva abundance across spatiotemporal scales and environmental gradients; (3) examining spatiotemporal patterns in the use of Austrovenus as attachment substrate by Ulva; and (4) linking the results across methods to identify and propose scale-dependent mechanistic drivers (e.g., light availability, nutrient concentration, sediment characteristics, hydrodynamics) of foundation species abundance and their associated biodiversity (Gribben et al, 2019). We hope this approach can provide a more comprehensive overview of how foundation species affect estuarine biodiversity, as well as a guideline to efficiently monitor their responses to disturbances and extreme environmental events, such as storms or marine heatwaves (Castorani et al, 2018;Montie & Thomsen, 2023b;Smale et al, 2022). We hypothesized that the abundance of Ulva and Austrovenus varied with season, site, and tidal elevation, being more abundant in the warmer season, at an "oceanic" site, and at lower elevation, due to higher metabolic rates, lower salinity stress, and lower desiccation stress, respectively (Adkins et al, 2016;Clemente & Thomsen, 2023).…”