Control of phytoplankton in a shelf sea: Determination of the main drivers based on the Helgoland Roads Time Series

Wiltshire, Karen Helen; Boersma, Maarten; Carstens, Kristine; Kraberg, Alexandra; Peters, Silvia; Scharfe, Mirco

doi:10.1016/j.seares.2015.06.022

Cited by 69 publications

(63 citation statements)

References 60 publications

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“…Although the specific interactions among phytoplankton, nutrients, water column mixing, and 65 grazers mean that spatial extents and temporal courses of spring blooms are highly variable 66 (Martinez et al, 2011;Daniels et al, 2015), dynamic changes in primary producer communities during 67 spring blooms can be closely tracked (Wiltshire et al, 2015;Sarker et al 2018; Scharfe and Wiltshire, 68 2019). Less is known, however, about the composition and structure of complex organic matter that 69 they produce in response to nutrient and light availability, and as they are affected by viruses and 70 grazing (e.g.…”

Section: Introduction 61mentioning

confidence: 99%

Short-term changes in polysaccharide utilization mechanisms of marine bacterioplankton during a spring phytoplankton bloom

Reintjes

Fuchs

Scharfe

et al. 2020

Preprint

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SummarySpring phytoplankton blooms in temperate environments contribute disproportionately to global marine productivity. Bloom-derived organic matter, much of it occurring as polysaccharides, fuels biogeochemical cycles driven by interacting autotrophic and heterotrophic communities. We tracked changes in the mode of polysaccharide utilization by heterotrophic bacteria during the course of a diatom-dominated bloom in the German Bight, North Sea. Polysaccharides can be taken up in a ‘selfish’ mode, where initial hydrolysis is coupled to transport into the periplasm, such that little to no low molecular weight (LMW) products are externally released to the environment. Alternatively, polysaccharides hydrolyzed by cell-surface attached or free extracellular enzymes (external hydrolysis) yield LMW products available to the wider bacterioplankton community. In the early bloom phase, selfish activity was accompanied by low extracellular hydrolysis rates of a few polysaccharides. As the bloom progressed, selfish uptake increased markedly, and external hydrolysis rates increased, but only for a limited range of substrates. The late bloom phase was characterized by high external hydrolysis rates of a broad range of polysaccharides, and reduced selfish uptake of polysaccharides, except for laminarin. Substrate utilization mode is related both to substrate structural complexity and to the bloom-stage dependent composition of the heterotrophic bacterial community.Originality statementThe means by which heterotrophic bacteria cooperate and compete to obtain substrates is a key factor determining the rate and location at which organic matter is cycled in the ocean. Much of this organic matter is high molecular weight (HMW), and must be enzymatically hydrolyzed to smaller pieces to be processed by bacterial communities. Some of these enzyme-producing bacteria are ‘selfish’, processing HMW organic matter without releasing low molecular weight (LMW) products to the environment. Other bacteria hydrolyze HMW substrates in a manner that releases LMW products to the wider bacterial community. How these mechanisms of substrate hydrolysis work against a changing background of organic matter supply is unclear. Here, we measured changing rates and mechanisms of substrate processing during the course of a natural phytoplankton bloom in the North Sea. Selfish bacteria generally dominate in the initial bloom stages, but a greater supply of increasingly complex substrates in later bloom stages leads to external hydrolysis of a wider range of substrates, increasing the supply of LMW hydrolysis products to the wider bacterial community.

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Section: Introduction 61mentioning

confidence: 99%

Short-term changes in polysaccharide utilization mechanisms of marine bacterioplankton during a spring phytoplankton bloom

Reintjes

Fuchs

Scharfe

et al. 2020

Preprint

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“…In diesem Jahrhundert hat sich die Erhöhung der Diatomeendichten und eine Verringerung der Dichten der Dinoflagellaten weiter durchgesetzt (Wiltshire et al 2010;Boersma et al 2015). Da Dinoflagellaten eine sehr wichtige Nahrungsquelle für neritische Copepoden darstellen (Gentsch et al 2009), hat sich die Nahrungssituation für die Copepoden verschlechtert (AlvarezFernandez et al 2012), was potenziell zu einer Verringerung der Dichten der herbivoren und omnivoren Copepoden geführt hat (Boersma et al 2015).…”

Section: Planktonunclassified

“…Da Dinoflagellaten eine sehr wichtige Nahrungsquelle für neritische Copepoden darstellen (Gentsch et al 2009), hat sich die Nahrungssituation für die Copepoden verschlechtert (AlvarezFernandez et al 2012), was potenziell zu einer Verringerung der Dichten der herbivoren und omnivoren Copepoden geführt hat (Boersma et al 2015). Zudem hat durch die abnehmenden Phosphoreinträge in die Deutsche Bucht die Qualität der Algen als Futter für Copepoden (Malzahn und Boersma 2012) Neumann et al (2013b) analysierten und verglichen die räumli-che Verbreitung der Gemeinschaften von Fischen sowie In-und Epifauna in der deutschen Ausschließlichen Wirtschaftszone (AWZ), um darauf basierend benthische Habitate zu identifizieren.…”

Section: Planktonunclassified

Aquatische Ökosysteme: Nordsee, Wattenmeer, Elbeästuar und Ostsee

Beusekom¹,

Thiel

Bobsien

et al. 2018

Hamburger Klimabericht – Wissen Über Klima, Klimawandel Und Auswirkungen in Hamburg Und Norddeutschland

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“…However, the Biologische Anstalt Helgoland is probably most famous for its Helgoland Roads time series which were initiated in 1962 (Wiltshire & Dürselen, 2004;Wiltshire et al, 2010Wiltshire et al, , 2015, with much older contextual datasets even dating back to the start of the 20th century (Kraberg et al, 2015). The Helgoland Roads time series has been in operation continuously since 1962 and not only provides work-daily phytoplankton and thrice-weekly zooplankton counts but also nutrient, temperature, salinity and Secchi depth data, making Helgoland Roads one of the most detailed and highly resolved time series in the world, also augmenting the marine macroalgal and physiological work at Helgoland.…”

Section: Introduction To the Embs Special Issuementioning

confidence: 99%