21st-century rise in anthropogenic nitrogen deposition on a remote coral reef

TY - JOUR

T1 - 21st-century rise in anthropogenic nitrogen deposition on a remote coral reef

AU - Ren, Haojia

AU - Chen, Yi-Chi

AU - Wang, Xingchen T.

AU - Wong, George T F

AU - Cohen, Anne L.

AU - DeCarlo, Thomas M.

AU - Weigand, Mira A.

AU - Mii, Horng-Sheng

AU - Sigman, Daniel M.

PY - 2017

Y1 - 2017

N2 - Nitrogen is an essential nutrient for phytoplankton growth. Nitrogen is primarily supplied to the surface ocean by mixing from below. However, as fertilizer use and combustion of fossil fuels rise, the atmosphere is expected to become an increasingly important source. Ren et al. measured nitrogen isotopes in organic matter from a South China Sea coral (see the Perspective by Boyle). Their findings suggest that atmospheric deposition of anthropogenic nitrogen began right at the end of the 20th century. This pathway now supplies nearly one quarter of the annual nitrogen input to the surface ocean in this region.Science, this issue p. 749; see also p. 700With the rapid rise in pollution-associated nitrogen inputs to the western Pacific, it has been suggested that even the open ocean has been affected. In a coral core from Dongsha Atoll, a remote coral reef ecosystem, we observe a decline in the 15N/14N of coral skeletontextendashbound organic matter, which signals increased deposition of anthropogenic atmospheric N on the open ocean and its incorporation into plankton and, in turn, the atoll corals. The first clear change occurred just before 2000 CE, decades later than predicted by other work. The amplitude of change suggests that, by 2010, anthropogenic atmospheric N deposition represented 20 textpm 5% of the annual N input to the surface ocean in this region, which appears to be at the lower end of other estimates.

AB - Nitrogen is an essential nutrient for phytoplankton growth. Nitrogen is primarily supplied to the surface ocean by mixing from below. However, as fertilizer use and combustion of fossil fuels rise, the atmosphere is expected to become an increasingly important source. Ren et al. measured nitrogen isotopes in organic matter from a South China Sea coral (see the Perspective by Boyle). Their findings suggest that atmospheric deposition of anthropogenic nitrogen began right at the end of the 20th century. This pathway now supplies nearly one quarter of the annual nitrogen input to the surface ocean in this region.Science, this issue p. 749; see also p. 700With the rapid rise in pollution-associated nitrogen inputs to the western Pacific, it has been suggested that even the open ocean has been affected. In a coral core from Dongsha Atoll, a remote coral reef ecosystem, we observe a decline in the 15N/14N of coral skeletontextendashbound organic matter, which signals increased deposition of anthropogenic atmospheric N on the open ocean and its incorporation into plankton and, in turn, the atoll corals. The first clear change occurred just before 2000 CE, decades later than predicted by other work. The amplitude of change suggests that, by 2010, anthropogenic atmospheric N deposition represented 20 textpm 5% of the annual N input to the surface ocean in this region, which appears to be at the lower end of other estimates.

U2 - 10.1126/science.aal3869

DO - 10.1126/science.aal3869

M3 - Article

VL - 356

SP - 749

EP - 752

JO - Science

JF - Science

SN - 0036-8075

IS - 6339

ER -