دورية أكاديمية
Contribution and pathways of diazotroph-derived nitrogen to zooplankton during the VAHINE mesocosm experiment in the oligotrophic New Caledonia lagoon
| العنوان: | Contribution and pathways of diazotroph-derived nitrogen to zooplankton during the VAHINE mesocosm experiment in the oligotrophic New Caledonia lagoon |
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| المؤلفون: | Hunt, Brian P. V., Bonnet, Sophie, Berthelot, Hugo, Conroy, Brandon J., Foster, Rachel A., Pagano, Marc |
| المصدر: | VIMS Articles |
| بيانات النشر: | W&M ScholarWorks |
| سنة النشر: | 2016 |
| المجموعة: | College of William |
| مصطلحات موضوعية: | DISSOLVED ORGANIC NITROGEN, NORTH PACIFIC-OCEAN, MARINE CYANOBACTERIUM TRICHODESMIUM, CORAL-REEF LAGOON, N-2 FIXATION, ISOTOPIC COMPOSITION, DINITROGEN FIXATION, PLANKTON BIOMASS, ATLANTIC-OCEAN, SOUTHERN-OCEAN, Biological Sciences Peer-Reviewed Articles, Marine Biology |
| الوصف: | In oligotrophic tropical and subtropical oceans, where strong stratification can limit the replenishment of surface nitrate, dinitrogen (N-2) fixation by diazotrophs can represent a significant source of nitrogen (N) for primary production. The VAHINE (VAriability of vertical and tropHIc transfer of fixed N-2 in the south-wEst Pacific) experiment was designed to examine the fate of diazotroph-derived nitrogen (DDN) in such ecosystems. In austral summer 2013, three large ( similar to aEuro parts per thousand aEuro-50aEuro-m(3)) in situ mesocosms were deployed for 23 days in the New Caledonia lagoon, an ecosystem that typifies the low-nutrient, low-chlorophyll environment, to stimulate diazotroph production. The zooplankton component of the study aimed to measure the incorporation of DDN into zooplankton biomass, and assess the role of direct diazotroph grazing by zooplankton as a DDN uptake pathway. Inside the mesocosms, the diatom-diazotroph association (DDA) het-1 predominated during days 5-15 while the unicellular diazotrophic cyanobacteria UCYN-C predominated during days 15-23. A Trichodesmium bloom was observed in the lagoon (outside the mesocosms) towards the end of the experiment. The zooplankton community was dominated by copepods (63aEuro-% of total abundance) for the duration of the experiment. Using two-source N isotope mixing models we estimated a mean similar to aEuro parts per thousand aEuro-28aEuro-% contribution of DDN to zooplankton nitrogen biomass at the start of the experiment, indicating that the natural summer peak of N-2 fixation in the lagoon was already contributing significantly to the zooplankton. Stimulation of N-2 fixation in the mesocosms corresponded with a generally low-level enhancement of DDN contribution to zooplankton nitrogen biomass, but with a peak of similar to aEuro parts per thousand aEuro-73aEuro-% in mesocosm 1 following the UCYN-C bloom. qPCR analysis targeting four of the common diazotroph groups present in the mesocosms (Trichodesmium, het-1, het-2, UCYN-C) ... |
| نوع الوثيقة: | text |
| وصف الملف: | application/pdf |
| اللغة: | unknown |
| العلاقة: | https://scholarworks.wm.edu/vimsarticles/37Test; https://scholarworks.wm.edu/context/vimsarticles/article/1036/viewcontent/bg_13_3131_2016.pdfTest |
| DOI: | 10.5194/bg-13-3131-2016 |
| الإتاحة: | https://doi.org/10.5194/bg-13-3131-2016Test https://scholarworks.wm.edu/vimsarticles/37Test https://scholarworks.wm.edu/context/vimsarticles/article/1036/viewcontent/bg_13_3131_2016.pdfTest |
| حقوق: | http://creativecommons.org/licenses/by/4.0Test/ |
| رقم الانضمام: | edsbas.51A0F9F |
| قاعدة البيانات: | BASE |
| DOI: | 10.5194/bg-13-3131-2016 |
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