Sources of iron and phosphate affect the distribution of diazotrophs in the North Atlantic
Biological nitrogen fixation (BNF) supplies nutrient-depleted oceanic surface waters with new biologically available fixed nitrogen. Diazotrophs are the only organisms that can fix dinitrogen, but the factors controlling their distribution patterns in the ocean are not well und erstood. In this stud...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | en_US |
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Elsevier
2019
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| Online Access: | http://hdl.handle.net/1721.1/120778 https://orcid.org/0000-0002-6394-1866 |
| _version_ | 1811091835103215616 |
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| author | Ratten, Jenni-Marie LaRoche, Julie Desai, Dhwani K. Shelley, Rachel U. Landing, William M. Cutter, Gregory A. Langlois, Rebecca J. Boyle, Edward A |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Ratten, Jenni-Marie LaRoche, Julie Desai, Dhwani K. Shelley, Rachel U. Landing, William M. Cutter, Gregory A. Langlois, Rebecca J. Boyle, Edward A |
| author_sort | Ratten, Jenni-Marie |
| collection | MIT |
| description | Biological nitrogen fixation (BNF) supplies nutrient-depleted oceanic surface waters with new biologically available fixed nitrogen. Diazotrophs are the only organisms that can fix dinitrogen, but the factors controlling their distribution patterns in the ocean are not well und erstood. In this study, the relative abundances of eight diazotrophic phylotypes in the subtropical North Atlantic Ocean were determined by quantitative PCR (qPCR) of the nifH gene using TaqMan probes. A total of 152 samples were collected at 27 stations during two GEOTRACES cruises; Lisbon, Portugal to Mindelo, Cape Verde Islands (USGT10) and Woods Hole, MA, USA via the Bermuda Time Series (BATS) to Praia, Cape Verde Islands (USGT11). Seven of the eight diazotrophic phylotypes tested were detected. These included free-li ving and symbiotic cyanobacteria (unicellular groups (UCYN) A, B and C, Trichodesmium , the diatom-associated cyanobacteria Rhizoselinia–Richelia and Hemiaulus–Richelia and γ-proteobacterium (Gamma A, AY896371). The nifH gene abundances were analyzed in the context of a large set of hydrographic parameters, macronutrient and trace metal concentrations measured in parallel with DNA samples using the PRIMER-E software. The environmental variables that most in fluenced the abundances and distribution of the diazotrophic ph ylotypes were determined. We observed a geographic segregation of diazotrophic phylotypes between east and west, with UCYN A, UCYN B and UCYN C and the Rhizosolenia–Richelia symbiont associated with the eastern North Atlantic (east of 40°W), and Trichodesmium and Gamma A detected across the basin .Hemiaulus–Richelia symbionts were primarily found in temperate waters near the North American coast. The highest diazotrophic phylotype abundance and diversity were associated with temperatures greater than 22 °C in the surface mixed layer, a high supply of iron from North African aeolian mineral dust deposition and from remi neralized nutrients upwelled at the edge of the oxygen minimum zone off the north western coast of Africa. |
| first_indexed | 2024-09-23T15:08:48Z |
| format | Article |
| id | mit-1721.1/120778 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T15:08:48Z |
| publishDate | 2019 |
| publisher | Elsevier |
| record_format | dspace |
| spelling | mit-1721.1/1207782022-10-02T00:55:48Z Sources of iron and phosphate affect the distribution of diazotrophs in the North Atlantic Ratten, Jenni-Marie LaRoche, Julie Desai, Dhwani K. Shelley, Rachel U. Landing, William M. Cutter, Gregory A. Langlois, Rebecca J. Boyle, Edward A Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Boyle, Edward Boyle, Edward A Biological nitrogen fixation (BNF) supplies nutrient-depleted oceanic surface waters with new biologically available fixed nitrogen. Diazotrophs are the only organisms that can fix dinitrogen, but the factors controlling their distribution patterns in the ocean are not well und erstood. In this study, the relative abundances of eight diazotrophic phylotypes in the subtropical North Atlantic Ocean were determined by quantitative PCR (qPCR) of the nifH gene using TaqMan probes. A total of 152 samples were collected at 27 stations during two GEOTRACES cruises; Lisbon, Portugal to Mindelo, Cape Verde Islands (USGT10) and Woods Hole, MA, USA via the Bermuda Time Series (BATS) to Praia, Cape Verde Islands (USGT11). Seven of the eight diazotrophic phylotypes tested were detected. These included free-li ving and symbiotic cyanobacteria (unicellular groups (UCYN) A, B and C, Trichodesmium , the diatom-associated cyanobacteria Rhizoselinia–Richelia and Hemiaulus–Richelia and γ-proteobacterium (Gamma A, AY896371). The nifH gene abundances were analyzed in the context of a large set of hydrographic parameters, macronutrient and trace metal concentrations measured in parallel with DNA samples using the PRIMER-E software. The environmental variables that most in fluenced the abundances and distribution of the diazotrophic ph ylotypes were determined. We observed a geographic segregation of diazotrophic phylotypes between east and west, with UCYN A, UCYN B and UCYN C and the Rhizosolenia–Richelia symbiont associated with the eastern North Atlantic (east of 40°W), and Trichodesmium and Gamma A detected across the basin .Hemiaulus–Richelia symbionts were primarily found in temperate waters near the North American coast. The highest diazotrophic phylotype abundance and diversity were associated with temperatures greater than 22 °C in the surface mixed layer, a high supply of iron from North African aeolian mineral dust deposition and from remi neralized nutrients upwelled at the edge of the oxygen minimum zone off the north western coast of Africa. 2019-03-07T14:25:04Z 2019-03-07T14:25:04Z 2015-06 2014-11 Article http://purl.org/eprint/type/JournalArticle 09670645 http://hdl.handle.net/1721.1/120778 Ratten, Jenni-Marie, Julie LaRoche, Dhwani K. Desai, Rachel U. Shelley, William M. Landing, Ed Boyle, Gregory A. Cutter, and Rebecca J. Langlois. “Sources of Iron and Phosphate Affect the Distribution of Diazotrophs in the North Atlantic.” Deep Sea Research Part II: Topical Studies in Oceanography 116 (June 2015): 332–341. https://orcid.org/0000-0002-6394-1866 en_US https://doi.org/10.1016/j.dsr2.2014.11.012 Deep Sea Research Part II: Topical Studies in Oceanography Creative Commons Attribution-NonCommercial-NoDerivs License http://creativecommons.org/licenses/by-nc-nd/4.0/ application/pdf Elsevier Prof. Boyle via Chris Sherratt |
| spellingShingle | Ratten, Jenni-Marie LaRoche, Julie Desai, Dhwani K. Shelley, Rachel U. Landing, William M. Cutter, Gregory A. Langlois, Rebecca J. Boyle, Edward A Sources of iron and phosphate affect the distribution of diazotrophs in the North Atlantic |
| title | Sources of iron and phosphate affect the distribution of diazotrophs in the North Atlantic |
| title_full | Sources of iron and phosphate affect the distribution of diazotrophs in the North Atlantic |
| title_fullStr | Sources of iron and phosphate affect the distribution of diazotrophs in the North Atlantic |
| title_full_unstemmed | Sources of iron and phosphate affect the distribution of diazotrophs in the North Atlantic |
| title_short | Sources of iron and phosphate affect the distribution of diazotrophs in the North Atlantic |
| title_sort | sources of iron and phosphate affect the distribution of diazotrophs in the north atlantic |
| url | http://hdl.handle.net/1721.1/120778 https://orcid.org/0000-0002-6394-1866 |
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