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Abstract Gelatinous zooplankton play a crucial role in pelagic marine food webs, however, due to methodological challenges and persistent misconceptions of their importance, the trophic role of gelatinous zooplankton remains poorly investigated. This is particularly true for small gelatinous zooplankton including the marine pelagic tunicate,Dolioletta gegenbauri.D. gegenbauriand other doliolid species occur persistently on wide subtropical shelves where they often produce massive blooms in association with shelf upwelling conditions. As efficient filter feeders and prodigious producers of relatively low‐density organic‐rich aggregates, doliolids are understood to contribute significantly to shelf production, pelagic ecology, and pelagic–benthic coupling. Utilizing molecular gut content analysis and stable isotope analysis approaches, the trophic interactions of doliolids were explored during bloom and non‐bloom conditions on the South Atlantic Bight continental shelf in the Western North Atlantic. Based on molecular gut content analysis, relative ingestion selectivity varied withD. gegenbaurilife stage. At all life stages, doliolids ingested a wide range of prey types and sizes, but exhibited selectivity for larger prey types including diatoms, ciliates, and metazoans. Experimental growth studies confirmed that metazoan prey were ingested, but indicated that they were not digested and assimilated. Stable isotopic composition (δ13C and δ15N) of wild‐caught doliolids, during bloom and non‐bloom conditions, were most consistent with a detrital‐supplemented diet. These observations suggest that the feeding ecology ofD. gegenbauriis more complex than previously reported, and have strong and unusual linkages to the microbial food web.
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This content will become publicly available on December 1, 2026
Foundation Species Modulate Microbial Benthic–Pelagic Coupling in the Rocky Intertidal
ABSTRACT Benthic–pelagic coupling, the reciprocal exchange of materials between benthic and pelagic habitats, has traditionally emphasised pelagic influences on benthic systems. Yet, the role of benthic biological processes in shaping pelagic microbial dynamics remains underexplored. We investigated how surfgrass and mussels regulate nitrogen and dissolved organic matter (DOM) cycling and their cascading effects on heterotrophic bacteria in Oregon tide pools. We quantified biogeochemical fluxes and bacterial responses before and after foundation species removal during contrasting upwelling regimes. Mussel‐dominated pools released high concentrations of ammonium and nitrate, while surfgrass pools transformed DOM that fueled bacterial growth; upwelling intensified these benthic–pelagic linkages. Removing foundation species dampened nutrient release in mussel pools and reduced DOM‐fueled bacterial growth in surfgrass pools, ultimately decoupling benthic productivity from pelagic microbial growth. Our results demonstrate the critical role of foundation species to pelagic microbial processes and underscore the vulnerability of coastal microbial dynamics to their global decline.
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- PAR ID:
- 10656170
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Ecology Letters
- Volume:
- 28
- Issue:
- 12
- ISSN:
- 1461-023X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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