Abstract Biogeochemical reactions produce volatile halocarbons and semi‐ to nonvolatile dissolved organic halogens (DOX) in marine systems. The former has a large influence on atmospheric chemistry, but little is known about DOX. Here, we present depth profiles of dissolved organic bromine (DOBr) and ‐iodine (DOI) isolated from the Central North Atlantic and the Central North Pacific. DOX ranged from ∼5 to 11 nM in the surface and decreased to ∼1 to 7 nM below 1,500 m. Relative to DOI, DOBr is elevated and more stable at depth. Moreover, 92 individual DOBr molecular ions were identified by high‐resolution mass spectrometry for the first time in seawater using a solid phase extraction/sequential elution technique. Similar DOBr ions with an oxygen‐to‐carbon ratio of 0.35 and a hydrogen‐to‐carbon ratio of 1.3 were present throughout the water column. Thus, deep ocean DOBr may be a hitherto overlooked component of marine refractory organic matter.
Observations from the Little Bunker
Last updated: December 30, 2025 02:11 PM
Atmospheric CO₂
427.9 ppm
+18.1
ppm/year
Atmospheric CH₄
1930.95 ppb
+-3.5
ppb/year
Global Temperature
+1.48 °C
Peak: +1.73°C
World Population
8.1 billion
+67
million/year