1
|
Ahme A, Happe A, Striebel M, Cabrerizo MJ, Olsson M, Giesler J, Schulte-Hillen R, Sentimenti A, Kühne N, John U. Warming increases the compositional and functional variability of a temperate protist community. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 926:171971. [PMID: 38547992 DOI: 10.1016/j.scitotenv.2024.171971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 03/22/2024] [Accepted: 03/23/2024] [Indexed: 04/06/2024]
Abstract
Phototrophic protists are a fundamental component of the world's oceans by serving as the primary source of energy, oxygen, and organic nutrients for the entire ecosystem. Due to the high thermal seasonality of their habitat, temperate protists could harbour many well-adapted species that tolerate ocean warming. However, these species may not sustain ecosystem functions equally well. To address these uncertainties, we conducted a 30-day mesocosm experiment to investigate how moderate (12 °C) and substantial (18 °C) warming compared to ambient conditions (6 °C) affect the composition (18S rRNA metabarcoding) and ecosystem functions (biomass, gross oxygen productivity, nutritional quality - C:N and C:P ratio) of a North Sea spring bloom community. Our results revealed warming-driven shifts in dominant protist groups, with haptophytes thriving at 12 °C and diatoms at 18 °C. Species responses primarily depended on the species' thermal traits, with indirect temperature effects on grazing being less relevant and phosphorus acting as a critical modulator. The species Phaeocystis globosa showed highest biomass on low phosphate concentrations and relatively increased in some replicates of both warming treatments. In line with this, the C:P ratio varied more with the presence of P. globosa than with temperature. Examining further ecosystem responses under warming, our study revealed lowered gross oxygen productivity but increased biomass accumulation whereas the C:N ratio remained unaltered. Although North Sea species exhibited resilience to elevated temperatures, a diminished functional similarity and heightened compositional variability indicate potential ecosystem repercussions for higher trophic levels. In conclusion, our research stresses the multifaceted nature of temperature effects on protist communities, emphasising the need for a holistic understanding that encompasses trait-based responses, indirect effects, and functional dynamics in the face of exacerbating temperature changes.
Collapse
Affiliation(s)
- Antonia Ahme
- Alfred-Wegener-Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany.
| | - Anika Happe
- Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, Schleusenstraße 1, 26382 Wilhelmshaven, Germany
| | - Maren Striebel
- Institute for Chemistry and Biology of the Marine Environment (ICBM), University of Oldenburg, Schleusenstraße 1, 26382 Wilhelmshaven, Germany
| | - Marco J Cabrerizo
- Department of Ecology, University of Granada, Campus Fuentenueva s/n 1, 18071 Granada, Spain; Department of Ecology and Animal Biology, University of Vigo, Campus Lagoas Marcosende s/n, 36310 Vigo, Spain
| | - Markus Olsson
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Svante Arrhenius väg 20A, 106 91 Stockholm, Sweden
| | - Jakob Giesler
- Alfred-Wegener-Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
| | - Ruben Schulte-Hillen
- Albert-Ludwigs-Universität Freiburg, Fahnenbergplatz, 79104 Freiburg i.Br., Germany
| | - Alexander Sentimenti
- Albert-Ludwigs-Universität Freiburg, Fahnenbergplatz, 79104 Freiburg i.Br., Germany
| | - Nancy Kühne
- Alfred-Wegener-Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
| | - Uwe John
- Alfred-Wegener-Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany; Helmholtz Institute for Functional Marine Biodiversity at the University of Oldenburg, Ammerländer Heersstraße 231, 26129 Oldenburg, Germany
| |
Collapse
|
2
|
Selph KE, Landry MR, Taylor AG, Gutiérrez-Rodríguez A, Stukel MR, Wokuluk J, Pasulka A. Phytoplankton production and taxon-specific growth rates in the Costa Rica Dome. JOURNAL OF PLANKTON RESEARCH 2016; 38:199-215. [PMID: 27275025 PMCID: PMC4889980 DOI: 10.1093/plankt/fbv063] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2015] [Accepted: 07/13/2015] [Indexed: 05/25/2023]
Abstract
During summer 2010, we investigated phytoplankton production and growth rates at 19 stations in the eastern tropical Pacific, where winds and strong opposing currents generate the Costa Rica Dome (CRD), an open-ocean upwelling feature. Primary production (14C-incorporation) and group-specific growth and net growth rates (two-treatment seawater dilution method) were estimated from samples incubated in situ at eight depths. Our cruise coincided with a mild El Niño event, and only weak upwelling was observed in the CRD. Nevertheless, the highest phytoplankton abundances were found near the dome center. However, mixed-layer growth rates were lowest in the dome center (∼0.5-0.9 day-1), but higher on the edge of the dome (∼0.9-1.0 day-1) and in adjacent coastal waters (0.9-1.3 day-1). We found good agreement between independent methods to estimate growth rates. Mixed-layer growth rates of Prochlorococcus and Synechococcus were largely balanced by mortality, whereas eukaryotic phytoplankton showed positive net growth (∼0.5-0.6 day-1), that is, growth available to support larger (mesozooplankton) consumer biomass. These are the first group-specific phytoplankton rate estimates in this region, and they demonstrate that integrated primary production is high, exceeding 1 g C m-2 day-1 on average, even during a period of reduced upwelling.
Collapse
Affiliation(s)
- Karen E. Selph
- Department of Oceanography, University of Hawaii at Manoa, Honolulu, HI 96822, USA
| | - Michael R. Landry
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
| | - Andrew G. Taylor
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
| | - Andrés Gutiérrez-Rodríguez
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
- Centre National de la Recherche Scientifique and Universite Pierre et Marie Curie, Station Biologique, 29680 Roscoff, France
| | - Michael R. Stukel
- Earth, Ocean and Atmospheric Science, Florida State University, Tallahassee, FL 32306, USA
| | - John Wokuluk
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
| | - Alexis Pasulka
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
- Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| |
Collapse
|
3
|
Gutiérrez-Rodríguez A, Selph KE, Landry MR. Phytoplankton growth and microzooplankton grazing dynamics across vertical environmental gradients determined by transplant in situ dilution experiments. JOURNAL OF PLANKTON RESEARCH 2016; 38:271-289. [PMID: 27275030 PMCID: PMC4889981 DOI: 10.1093/plankt/fbv074] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 08/09/2015] [Indexed: 05/25/2023]
Abstract
The Costa Rica Dome (CRD) represents a classic case of the bloom-forming capacity of small phytoplankton. Unlike other upwelling systems, autotrophic biomass in the CRD is dominated by picocyanobacteria and small eukaryotes that outcompete larger diatoms and reach extremely high biomass levels. We investigated responses of the subsurface phytoplankton community of the CRD to changes associated with vertical displacement of water masses, coupling in situ transplanted dilution experiments with flow cytometry and epifluorescence microscopy to assess group-specific dynamics. Growth rates of Synechococcus (SYN) and photosynthetic picoeukaryotes (PEUK) were positively correlated with light (Rpearson_SYN = 0.602 and Rpearson_PEUK = 0.588, P < 0.001). Growth rates of Prochlorococcus (PRO), likely affected by photoinhibition, were not light correlated (Rpearson_PRO = 0.101, P = 0.601). Overall, grazing and growth rates were closely coupled in all picophytoplankton groups (Rspearman_PRO = 0.572, Rspearman_SYN = 0.588, Rspearman_PEUK = 0.624), and net growth rates remained close to zero. Conversely, the abundance and biomass of larger phytoplankton, mainly diatoms, increased more than 10-fold in shallower transplant incubations indicating that, in addition to trace-metal chemistry, light also plays a significant role in controlling microphytoplankton populations in the CRD.
Collapse
Affiliation(s)
| | - Karen E Selph
- Department of Oceanography , University of Hawaii at Manoa , Honolulu, Hi 96822 , USA
| | - Michael R Landry
- Scripps Institution of Oceanography , 9500 Gilman Dr., La Jolla, CA 92093-0227 , USA
| |
Collapse
|
4
|
Goes JI, Gomes HDR, Selph KE, Landry MR. Biological response of Costa Rica Dome phytoplankton to Light, Silicic acid and Trace metals. JOURNAL OF PLANKTON RESEARCH 2016; 38:290-304. [PMID: 27275031 PMCID: PMC4889990 DOI: 10.1093/plankt/fbv108] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Accepted: 11/19/2015] [Indexed: 05/25/2023]
Abstract
The Costa Rica Dome (CRD) is a unique open-ocean upwelling system, with picophytoplankton dominance of phytoplankton biomass and suppressed diatoms, yet paradoxically high export of biogenic silica. As a part of Flux and Zinc Experiments cruise in summer (June-July 2010), we conducted shipboard incubation experiments in the CRD to examine the potential roles of Si, Zn, Fe and light as regulating factors of phytoplankton biomass and community structure. Estimates of photosynthetic quantum yields revealed an extremely stressed phytoplankton population that responded positively to additions of silicic acid, iron and zinc and higher light conditions. Size-fractioned Chl a yielded the surprising result that picophytoplankton, as well as larger phytoplankton, responded most to treatments with added silicic acid incubated at high incident light (HL + Si). The combination of Si and HL also led to increases in cell sizes of picoplankton, notably in Synechococcus. Such a response, coupled with the recent discovery of significant intracellular accumulation of Si in some picophytoplankton, suggests that small phytoplankton could play a potentially important role in Si cycling in the CRD, which may help to explain its peculiar export characteristics.
Collapse
Affiliation(s)
- Joaquim I. Goes
- Lamont Doherty Earth Observatory at Columbia University, Palisades, New York, NY 10964, USA
| | - Helga do Rosario Gomes
- Lamont Doherty Earth Observatory at Columbia University, Palisades, New York, NY 10964, USA
| | - Karen E. Selph
- Department of Oceanography, University of Hawaii at Manoa, Honululu, HI 96822, USA
| | - Michael R. Landry
- Scripps Institution of Oceanography, University of California at San Diego, 9500 Gilman Dr, La Jolla, CA 92093, USA
| |
Collapse
|
5
|
Landry MR, De Verneil A, Goes JI, Moffett JW. Plankton dynamics and biogeochemical fluxes in the Costa Rica Dome: introduction to the CRD Flux and Zinc Experiments. JOURNAL OF PLANKTON RESEARCH 2016; 38:167-182. [PMID: 27275023 PMCID: PMC4889988 DOI: 10.1093/plankt/fbv103] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2015] [Accepted: 11/09/2015] [Indexed: 05/25/2023]
Abstract
The Costa Rica Dome (CRD) is an open-ocean upwelling system in the Eastern Tropical Pacific that overlies the ocean's largest oxygen minimum zone (OMZ). The region has unique characteristics, biomass dominance by picophytoplankton, suppressed diatoms, high biomass of higher consumers and presumptive trace metal limitation, but is poorly understood in terms of pelagic stock and process relationships, including productivity and production controls. Here, we describe the goals, project design, physical context and major findings of the Flux and Zinc Experiments cruise conducted in June-July 2010 to assess trophic flux relationships and elemental controls on phytoplankton in the CRD. Despite sampling during a year of suppressed summertime surface chlorophyll, cruise results show high productivity (∼1 g C m-2 day-1), high new production relative to export, balanced production and grazing, disproportionate biomass-specific productivity of large phytoplankton and high zooplankton stocks. Zinc concentrations are low in surface waters relative to phosphorous and silicate in other regions, providing conditions conducive to picophytoplankton, like Synechococcus, with low Zn requirements. Experiments nonetheless highlight phytoplankton limitation or co-limitation by silicic acid, driven by a strong silica pump that is linked to low dissolution of biogenic silica in the cold shallow thermocline of the lower euphotic zone.
Collapse
Affiliation(s)
- Michael R Landry
- Scripps Institution of Oceanography, University of California at San Diego , 9500 Gilman Dr., La Jolla, CA 92093-0227 , USA
| | - Alain De Verneil
- Scripps Institution of Oceanography, University of California at San Diego , 9500 Gilman Dr., La Jolla, CA 92093-0227 , USA
| | - Joaquim I Goes
- Department of Marine Biology and Paleoenvironment , Lamont Doherty Earth Observatory at Columbia University , Palisades, NY 10964 , USA
| | - James W Moffett
- Department of Biological Sciences , University of Southern California , Los Angeles, CA 90089 , USA
| |
Collapse
|
6
|
Taylor AG, Landry MR, Freibott A, Selph KE, Gutiérrez-Rodríguez A. Patterns of microbial community biomass, composition and HPLC diagnostic pigments in the Costa Rica upwelling dome. JOURNAL OF PLANKTON RESEARCH 2016; 38:183-198. [PMID: 27275024 PMCID: PMC4889983 DOI: 10.1093/plankt/fbv086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2015] [Accepted: 09/10/2015] [Indexed: 05/10/2023]
Abstract
We investigated biomass, size-structure, composition, depth distributions and spatial variability of the phytoplankton community in the Costa Rica Dome (CRD) in June-July 2010. Euphotic zone profiles were sampled daily during Lagrangian experiments in and out of the dome region, and the community was analyzed using a combination of digital epifluorescence microscopy, flow cytometry and HPLC pigments. The mean depth-integrated biomass of phytoplankton ranged 2-fold, from 1089 to 1858 mg C m-2 (mean ± SE = 1378 ± 112 mg C m-2), among 4 water parcels tracked for 4 days. Corresponding mean (±SE) integrated values for total chlorophyll a (Chl a) and the ratio of autotrophic carbon to Chl a were 24.1 ± 1.5 mg Chl a m-2 and 57.5 ± 3.4, respectively. Absolute and relative contributions of picophytoplankton (∼60%), Synechococcus (>33%) and Prochlorococcus (17%) to phytoplankton community biomass were highest in the central dome region, while >20 µm phytoplankton accounted for ≤10%, and diatoms <2%, of biomass in all areas. Nonetheless, autotrophic flagellates, dominated by dinoflagellates, exceeded biomass contributions of Synechococcus at all locations. Order-of-magnitude discrepancies in the relative contributions of diatoms (overestimated) and dinoflagellates (underestimated) based on diagnostic pigments relative to microscopy highlight potential significant biases associated with making community inferences from pigments.
Collapse
Affiliation(s)
- Andrew G. Taylor
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
| | - Michael R. Landry
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
- corresponding author:
| | - Alexandra Freibott
- Scripps Institution of Oceanography, 9500 Gilman Dr., La Jolla, CA 92093-0227, USA
| | - Karen E. Selph
- Department of Oceanography, University of Hawaii At Manoa, Honolulu, HI 96822, USA
| | | |
Collapse
|