The importance of transparent exopolymer particles over ballast in determining both sinking and suspension of small particles during late summer in the Northeast Pacific Ocean
Bibliographic Data
| ID | 21242035 |
|---|---|
| Authors | Elisa Romanelli (0000-0001-7989-9108, University of California, Santa Barbara), Julia Sweet (0009-0002-9780-4621, University of California, Santa Barbara), S L C Giering (0000-0002-3090-1876, National Oceanography Centre), David A Siegel (0000-0003-1619-6119, University of California, Santa Barbara), Uta Passow (0000-0002-2296-6936, Memorial University of Newfoundland) |
| Year | 2023 |
| Volume | 11 |
| Issue | 1 |
| Publication date | 2023-09-13 |
| Open Access | Yes |
| Type | ARTICLE |
| Venue | Elementa Science of the Anthropocene (JOURNAL) |
| Journal identifiers | ISSN: 2325-1026 • E-ISSN: 2325-1026 |
| Publisher | University of California Press (PUBLISHER • US) |
| DOI | 10.1525/elementa.2022.00122 |
| OpenAlex | W4386771923 |
| Language | EN |
| Citations received | 1 |
| References cited | 91 |
Gravitational sinking of particles is a key pathway for the transport of particulate organic carbon (POC) to the deep ocean. Particle size and composition influence particle sinking velocity and thus play a critical role in controlling particle flux. Canonically, sinking particles that reach the mesopelagic are expected to be either large or ballasted by minerals. However, the presence of transparent exopolymer particles (TEP), which are positively buoyant, may also influence particle sinking velocity. We investigated the relationship between particle composition and sinking velocity during the Export Processes in the Ocean from RemoTe Sensing (EXPORTS) campaign in the Northeast Pacific Ocean using Marine Snow Catchers. Suspended and sinking particles were sized using FlowCam for particle imaging, and their biogeochemical composition was assessed by measuring the concentration of particulate organic carbon (POC) and nitrogen, particulate inorganic carbon, biogenic and lithogenic silica, and TEP. Sinking fluxes were also calculated. Overall, both suspended and sinking particles were small (<51 μm, diameter) in this late summer, oligotrophic system. Contrary to expectation, the ratio of ballast minerals to POC was higher for suspended particles than sinking particles. Further, suspended particles showed TEP-to-POC ratios three times higher than sinking particles. These ratios suggest that TEP content and not ballast dictated whether particles in this system would sink (low TEP) or remain suspended (high TEP). Fluxes of POC averaged 4.3 ± 2.5 mmol C m−2 d−1 at 50 m (n = 9) and decreased to 3.1 ± 1.1 mmol C m−2 d−1 at 300–500 m (n = 6). These flux estimates were slightly higher than fluxes measured during EXPORTS with drifting sediment traps and Thorium-234. A comparison between these approaches illustrates that small sinking particles were an important component of the POC flux in the mesopelagic of this late summer oligotrophic system
Biogeochemical cycle · Biological pump · Carbon dioxide · Exopolymer · Marine snow · Mesopelagic zone · Nutrient · Particulates · Pelagic zone · Phytoplankton · Redfield ratio · Total inorganic carbon · Water column · Chemistry · Environmental Science · Marine and coastal ecosystems · Ocean Acidification Effects and Responses · Oceanographic and Atmospheric Processes · Environmental Chemistry · Geology · Oceanography
High-resolution spatial and temporal measurements of particulate organic carbon flux using thorium-234 in the northeast Pacific Ocean during the EXport Processes in the Ocean from RemoTe Sensing field campaign
Phytoplankton size-class contributions to new and regenerated production during the EXPORTS Northeast Pacific Ocean field deployment
Concentrations, ratios, and sinking fluxes of major bioelements at Ocean Station Papa
High-resolution spatial and temporal measurements of particulate organic carbon flux using thorium-234 in the northeast Pacific Ocean during the EXport Processes in the Ocean from RemoTe Sensing field campaign
Biogenic sinking particle fluxes and sediment trap collection efficiency at Ocean Station Papa
The upper ocean silicon cycle of the subarctic Pacific during the EXPORTS field campaign
An operational overview of the EXport Processes in the Ocean from RemoTe Sensing (EXPORTS) Northeast Pacific field deployment
| Citations per year | 0.33 |
|---|---|
| Citation span | 2023 - 2023 (1) |
| Highly cited | No |