Trends in inorganic and organic carbon in a bloom of Emiliania huxleyi in the North Sea

Abstract. Continental shelf sediments are places of both rapid organic carbon turnover and accumulation, while at the same time increasingly subjected to human-induced disturbances. Recent research suggests that shelf sediments might have a role to play as a natural climate solution, e.g. by protecting the seafloor against human-induced disturbance. However, we have an incomplete understanding about the centres of organic carbon accumulation and storage on continental shelves. To better constrain the rate of accumulation and the mass of organic carbon that is stored in sediments, we developed and applied a spatial modelling framework that allows to estimate those quantities from sparse observations and predictor variables known or suspected to influence the spatial patterns of these parameters. This paper presents spatial distribution patterns of organic carbon densities and accumulation rates in the North Sea and Skagerrak. We found that organic carbon stocks and accumulation rates are highest in the Norwegian Trough, while large parts of the North Sea are characterised by low stocks and zero net-accumulation. The total stock of organic carbon that is stored in the upper 0.1 m of sediments amounted to 230.5 ± 134.5 Tg, of which approximately 26 % are stored in the Norwegian Trough. Rates of organic carbon accumulation in the Norwegian Trough are on par with those reported from nearby fjords. We provide baseline datasets that could be used in marine management, e.g. for the establishment of carbon protection zones. Additionally, we highlight the complex nature of continental shelves with zones of rapid carbon cycling and accumulation juxtaposed, which will require further detailed and spatially explicit analyses to constrain sedimentary organic carbon stocks and accumulation rates globally.

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Genotyping an <i>Emiliania huxleyi</i> (Prymnesiophyceae) bloom event in the North Sea reveals evidence of asexual reproduction

Biogeosciences Discussions ◽

10.5194/bgd-11-4359-2014 ◽

2014 ◽

Vol 11 (3) ◽

pp. 4359-4408 ◽

Cited By ~ 6

Author(s):

S. A. Krueger-Hadfield ◽

C. Balestreri ◽

J. Schroeder ◽

A. Highfield ◽

P. Helaouët ◽

...

Keyword(s):

North Sea ◽

Asexual Reproduction ◽

Small Sample Size ◽

Large Population ◽

Emiliania Huxleyi ◽

Small Sample ◽

Phytoplankton Species ◽

The North ◽

Generation Times ◽

The North Sea

Abstract. Due to the unprecedented rate at which our climate is changing, the ultimate consequence for many species is likely to be either extinction or migration to an alternate habitat. Certain species might, however, evolve at a rate that could make them resilient to the effects of a rapidly changing environment. This scenario is most likely to apply to species that have large population sizes and rapid generation times, such that the genetic variation required for adaptive evolution can be readily supplied. Emiliania huxleyi (Lohm.) Hay and Mohler (Prymnesiophyceae) is likely to be such a species as it is the most conspicuous extant calcareous phytoplankton species in our oceans with generation times of 1 day−1. Here we report on a validated set of microsatellites, in conjunction with the coccolithophore morphology motif genetic marker, to genotype 93 clonal isolates collected from across the world. Of these, 52 came from a single bloom event in the North Sea collected on the D366 UK Ocean Acidification cruise in June-July 2011. There were 26 multilocus genotypes (MLGs) encountered only once in the North Sea bloom and 8 MLGs encountered twice or up to six times. Each of these repeated MLGs exhibited Psex values of less than 0.05 indicating each repeated MLG was the product of asexual reproduction and not separate meiotic events. In addition, we show that the two most polymorphic microsatellite loci, EHMS37 and P01E05, are reporting on regions likely undergoing rapid genetic drift during asexual reproduction. Despite the small sample size, there were many more repeated genotypes than previously reported for other bloom-forming phytoplankton species, including a previously genotyped E. huxleyi bloom event. This study challenges our current assumption that sex is the predominant mode of reproduction during bloom events. Whilst genetic diversity is high amongst extant populations of E. huxleyi, the root cause for this diversity and ultimate fate of these populations still requires further examination. Nonetheless, we show that certain CMM genotypes are found everywhere; while others appear to have a regional bias.

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Primary production, calcification and macromolecular synthesis in a bloom of the coccolithophore Emiliania huxleyi in the North Sea

Marine Ecology Progress Series ◽

10.3354/meps157061 ◽

1997 ◽

Vol 157 ◽

pp. 61-77 ◽

Cited By ~ 26

Author(s):

E Marañón ◽

N González

Keyword(s):

Primary Production ◽

North Sea ◽

Emiliania Huxleyi ◽

Macromolecular Synthesis ◽

The North ◽

The North Sea

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Organic carbon densities and accumulation rates in surface sediments of the North Sea and Skagerrak

Biogeosciences ◽

10.5194/bg-18-2139-2021 ◽

2021 ◽

Vol 18 (6) ◽

pp. 2139-2160

Author(s):

Markus Diesing ◽

Terje Thorsnes ◽

Lilja Rún Bjarnadóttir

Keyword(s):

Organic Carbon ◽

North Sea ◽

Carbon Stocks ◽

Carbon Accumulation ◽

Anthropogenic Activity ◽

Accumulation Rates ◽

The North ◽

Continental Shelves ◽

Shelf Sediments ◽

The North Sea

Abstract. Continental shelf sediments are places of both rapid organic carbon turnover and accumulation, while at the same time increasingly subjected to human-induced disturbances. Recent research suggests that shelf sediments might have a role to play as a natural climate solution, e.g. by storing organic carbon if left undisturbed from anthropogenic activity. However, we have an incomplete understanding about the centres of organic carbon accumulation and storage on continental shelves. To better constrain the rate of accumulation and the mass of organic carbon that is stored in sediments, we developed and applied a spatial modelling framework that allows us to estimate those quantities from sparse observations and predictor variables known or suspected to influence the spatial patterns of these parameters. This paper presents spatial distribution patterns of organic carbon densities and accumulation rates in the North Sea and Skagerrak. We found that organic carbon stocks and accumulation rates are highest in the Norwegian Trough, while large parts of the North Sea are characterised by low stocks and zero net accumulation. The total stock of organic carbon that is stored in the upper 0.1 m of sediments amounted to 230.5 ± 134.5 Tg C, of which approximately 26 % is stored in the Norwegian Trough. Rates of organic carbon accumulation in the Norwegian Trough are comparable with those reported from nearby fjords. We provide baseline datasets that could be used in marine management, e.g. for the establishment of “carbon protection zones”. Additionally, we highlight the complex nature of continental shelves with zones of rapid carbon cycling and accumulation juxtaposed, which will require further detailed and spatially explicit analyses to constrain sedimentary organic carbon stocks and accumulation rates globally.

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Interactive Referee Comment on “Organic carbon in surface sediments of the North Sea and Skagerrak”

10.5194/bg-2020-352-rc2 ◽

2020 ◽

Author(s):

Anonymous

Keyword(s):

Organic Carbon ◽

North Sea ◽

Surface Sediments ◽

The North ◽

The North Sea

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The benthic environment of the North Sea (56° to 61°N)

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315400050141 ◽

1988 ◽

Vol 68 (1) ◽

pp. 125-141 ◽

Cited By ~ 33

Author(s):

D. Basford ◽

A. Eleftheriou

Keyword(s):

Trace Metals ◽

Organic Carbon ◽

North Sea ◽

Large Scale ◽

Clay Content ◽

The North ◽

Benthic Environment ◽

The North Sea ◽

Sedimentation Basins ◽

Physical And Chemical

In an attempt to describe the physical and chemical characteristics of the sediments as an environment for the invertebrate benthos, a total of 273 stations covering the sector from 56° N to 61° N in the North Sea was sampled. The sediment samples which were collected by grab and corer were analysed for particle size (as well as silt-clay content and sorting), organic carbon, plant pigments and trace metals (Cd, Pb, Zn, Ni, Co, Cu). On a smaller scale a few stations were sampled for redox potential, pH and pesticides.Taking into account the geological history and the on-going hydrographic processes, explanations for the formation of the sedimentary provinces in the North Sea were provided. The sediments were predominantly fine to medium sand, but there was a depth-related gradient with the finer grades, organic carbon and, to a lesser extent, plant pigment being found in the deeper sedimentation basins of the Fladen Grounds and Norwegian Trench.Trace metals and pesticide contaminants associated with the finer organic and inorganic fractions were higher in the sediments of the above deeper areas as well as in the vicinity of estuaries. It could be concluded that despite the enhanced concentrations of Cd, Ni, Pb and Co, at the east of Shetland, which were due to a geochemical anomaly, there was no evidence of any important or large-scale contamination of the North Sea as a whole.

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Genotyping an <i>Emiliania huxleyi</i> (prymnesiophyceae) bloom event in the North Sea reveals evidence of asexual reproduction

Biogeosciences ◽

10.5194/bg-11-5215-2014 ◽

2014 ◽

Vol 11 (18) ◽

pp. 5215-5234 ◽

Cited By ~ 19

Author(s):

S. A. Krueger-Hadfield ◽

C. Balestreri ◽

J. Schroeder ◽

A. Highfield ◽

P. Helaouët ◽

...

Keyword(s):

North Sea ◽

Asexual Reproduction ◽

Small Sample Size ◽

Large Population ◽

Emiliania Huxleyi ◽

Small Sample ◽

Phytoplankton Species ◽

The North ◽

The North Sea ◽

June July

Abstract. Due to the unprecedented rate at which our climate is changing, the ultimate consequence for many species is likely to be either extinction or migration to an alternate habitat. Certain species might, however, evolve at a rate that could make them resilient to the effects of a rapidly changing environment. This scenario is most likely to apply to species that have large population sizes and rapid generation times, such that the genetic variation required for adaptive evolution can be readily supplied. Emiliania huxleyi (Lohm.) Hay and Mohler (Prymnesiophyceae) is likely to be such a species, as it is the most conspicuous extant calcareous phytoplankton species in our oceans with growth rates of 1 day−1. Here we report on a validated set of microsatellites, in conjunction with the coccolithophore morphology motif genetic marker, to genotype 93 clonal isolates collected from across the world. Of these, 52 came from a single bloom event in the North Sea collected on the D366 United Kingdom Ocean Acidification cruise in June–July 2011. There were 26 multilocus genotypes (MLGs) encountered only once in the North Sea bloom and 8 MLGs encountered twice or up to six times. Each of these repeated MLGs exhibited Psex values of less than 0.05, indicating each repeated MLG was the product of asexual reproduction and not separate meiotic events. In addition, we show that the two most polymorphic microsatellite loci, EHMS37 and P01E05, are reporting on regions likely undergoing rapid genetic drift during asexual reproduction. Despite the small sample size, there were many more repeated genotypes than previously reported for other bloom-forming phytoplankton species, including a previously genotyped E. huxleyi bloom event. This study challenges the current assumption that sexual reproduction predominates during bloom events. Whilst genetic diversity is high amongst extant populations of E. huxleyi, the root cause for this diversity and ultimate fate of these populations still requires further examination. Nonetheless, we show that certain CMM genotypes are found everywhere, while others appear to have a regional bias.

Download Full-text