{"id":3622,"date":"2019-03-04T21:17:11","date_gmt":"2019-03-04T21:17:11","guid":{"rendered":"https:\/\/sites.nicholas.duke.edu\/cassar\/?p=3622"},"modified":"2020-06-11T18:40:49","modified_gmt":"2020-06-11T18:40:49","slug":"revisiting-the-distribution-of-marine-n2-fixation","status":"publish","type":"post","link":"https:\/\/sites.nicholas.duke.edu\/cassar\/revisiting-the-distribution-of-marine-n2-fixation\/","title":{"rendered":"Revisiting the distribution of marine N2 fixation"},"content":{"rendered":"<p>Marine N<sub>2<\/sub> fixation supports a significant portion of oceanic primary production by making N<sub>2<\/sub> bioavailable to planktonic communities, in the process influencing atmosphere-ocean carbon fluxes and our global climate. However, the geographical distribution and controlling factors of marine N<sub>2<\/sub> fixation remain elusive largely due to sparse observations. Here we present unprecedented high-resolution underway N<sub>2<\/sub> fixation estimates across over 6,000 kilometers of the western North Atlantic. Unexpectedly, we find increasing N<sub>2<\/sub> fixation rates from the oligotrophic Sargasso Sea to North America coastal waters, driven primarily by cyanobacterial diazotrophs. N<sub>2<\/sub> fixation is best correlated to phosphorus availability and chlorophyll-<em>a<\/em> concentration. Globally, intense N<sub>2<\/sub> fixation activity in the coastal oceans is validated by a meta-analysis of published observations and we estimate the annual coastal N<sub>2<\/sub> fixation flux to be 16.7 Tg N. This study broadens the biogeography of N<sub>2<\/sub> fixation, highlights the interplay of regulating factors, and reveals thriving diazotrophic communities in coastal waters with potential significance to the global nitrogen cycle.<\/p>\n<p><a href=\"https:\/\/www.nature.com\/articles\/s41467-019-08640-0\" target=\"_blank\" rel=\"noopener noreferrer\">For more information, see publication.<\/a><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" data-attachment-id=\"3624\" data-permalink=\"https:\/\/sites.nicholas.duke.edu\/cassar\/revisiting-the-distribution-of-marine-n2-fixation\/high-resolution-n2-fixation-rate-measurements-jpg\/\" data-orig-file=\"https:\/\/sites.nicholas.duke.edu\/cassar\/files\/2019\/03\/High-resolution-N2-fixation-rate-measurements.jpg.png\" data-orig-size=\"968,899\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"High-resolution N2 fixation rate measurements.jpg\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/sites.nicholas.duke.edu\/cassar\/files\/2019\/03\/High-resolution-N2-fixation-rate-measurements.jpg.png\" class=\"alignnone size-full wp-image-3624\" src=\"https:\/\/sites.nicholas.duke.edu\/cassar\/files\/2019\/03\/High-resolution-N2-fixation-rate-measurements.jpg.png\" alt=\"\" width=\"968\" height=\"899\" srcset=\"https:\/\/sites.nicholas.duke.edu\/cassar\/files\/2019\/03\/High-resolution-N2-fixation-rate-measurements.jpg.png 968w, https:\/\/sites.nicholas.duke.edu\/cassar\/files\/2019\/03\/High-resolution-N2-fixation-rate-measurements.jpg-300x279.png 300w, https:\/\/sites.nicholas.duke.edu\/cassar\/files\/2019\/03\/High-resolution-N2-fixation-rate-measurements.jpg-768x713.png 768w, https:\/\/sites.nicholas.duke.edu\/cassar\/files\/2019\/03\/High-resolution-N2-fixation-rate-measurements.jpg-676x628.png 676w\" sizes=\"auto, (max-width: 968px) 100vw, 968px\" \/><\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Marine N2 fixation supports a significant portion of oceanic primary production by making N2 bioavailable to planktonic communities, in the process influencing atmosphere-ocean carbon fluxes and our global climate. However, [&hellip;]<\/p>\n","protected":false},"author":1421,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[5],"tags":[],"class_list":["post-3622","post","type-post","status-publish","format-standard","hentry","category-lab-news","post-preview"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p9c288-Wq","jetpack_likes_enabled":true,"_links":{"self":[{"href":"https:\/\/sites.nicholas.duke.edu\/cassar\/wp-json\/wp\/v2\/posts\/3622","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sites.nicholas.duke.edu\/cassar\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sites.nicholas.duke.edu\/cassar\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sites.nicholas.duke.edu\/cassar\/wp-json\/wp\/v2\/users\/1421"}],"replies":[{"embeddable":true,"href":"https:\/\/sites.nicholas.duke.edu\/cassar\/wp-json\/wp\/v2\/comments?post=3622"}],"version-history":[{"count":1,"href":"https:\/\/sites.nicholas.duke.edu\/cassar\/wp-json\/wp\/v2\/posts\/3622\/revisions"}],"predecessor-version":[{"id":3625,"href":"https:\/\/sites.nicholas.duke.edu\/cassar\/wp-json\/wp\/v2\/posts\/3622\/revisions\/3625"}],"wp:attachment":[{"href":"https:\/\/sites.nicholas.duke.edu\/cassar\/wp-json\/wp\/v2\/media?parent=3622"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sites.nicholas.duke.edu\/cassar\/wp-json\/wp\/v2\/categories?post=3622"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sites.nicholas.duke.edu\/cassar\/wp-json\/wp\/v2\/tags?post=3622"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}