Unexpected changes in the oxic/anoxic interface in the Black Sea

  title={Unexpected changes in the oxic/anoxic interface in the Black Sea},
  author={James W. Murray and Hans W. Jannasch and Susumu Honjo and R. F. Anderson and William S. Reeburgh and Zafer Top and Gernot E. Friederich and Louis A. Codispoti and E. Izdar},
THE Black Sea is the largest anoxic marine basin in the world today1. Below the layer of oxygenated surface water, hydrogen sulphide builds up to concentrations as high as 425 μM in the deep water down to a maximum depth of 2,200 m (ref. 2). The hydrographic regime is characterized by low-salinity surface water of river origin overlying high-salinity deep water of Mediterranean origin1,3. A steep pycnocline, centred at about 50 m is the primary physical barrier to mixing and is the origin of… 
Changes in the hydrochemistry of the Black Sea inferred from water density profiles
DURING the past two decades, catastrophic changes have occurred in the Black Sea ecosystem: the influx of pollution from the major rivers has caused intense eutrophication at the northwest coastal
Oxic, suboxic, and anoxic conditions in the Black Sea
The Black Sea is the classic marine anoxic basin. It has an oxygenated surface layer overlying a sulfide containing (anoxic) deep layer. This condition has evolved because of the strong density
Understanding the Dynamics of the Oxic‐Anoxic Interface in the Black Sea
The Black Sea, the largest semienclosed anoxic basin on Earth, can be considered as an excellent natural laboratory for oxic and anoxic biogeochemical processes. The suboxic zone, a thin interface
Chemical variability in the Black Sea: implications of continuous vertical profiles that penetrated the oxic/anoxic interface
Abstract During the 1988 Black Sea Expedition, we employed a pumping system to generate continuous vertical profiles of nutrients, sulfide, temperature, salinity and light transmission to depths as
The Black Sea is a semi-enclosed marginal sea with a physical and chemical structure that is determined by its hydrological balance. Seawater flows in through the Bosporus. Freshwater inflow from
Stability of the oxic-anoxic interface in the Black Sea
We have examined the position of the oxic, suboxic and anoxic interfaces in the Black Sea between 1965-1992. It appears as if the suboxic zone (i.e. depths where DO and H 2 S <5 #M) has been a common
The short timescale variability of the oxygen inventory in the NE Black Sea slope water
Abstract. Warm winters have recently become common over the Black Sea, leading to the risk of shoaling oxygen penetration. The insufficient supply of oxygen to the near-bottom layer may result in a
Double Diffusive Intrusions, Mixing and Deep Sea Convection Processes in the Black Sea
Hydrographic measurements obtained during Leg 4 oceanographic expedition of the RV Knorr in the Black Sea point to important processes deserving scientific attention. The destabilizing effects of the


Vertical advection diffusion and redox potentials as controls on the distribution of manganese and other trace metals Dissolved in waters of the Black Sea
Profiles of dissolved manganese, copper, iron, and zinc show that the distributions of these elements are markedly affected by redox reactions at the boundary between oxygenated surface waters and
Distribution, abundance, and metabolic states of microorganisms in the water column and sediments of the Black Sea1
The vertical distribution, abundance, and metabolic states of microorganisms have been measured within the water column of the Black Sea, and scanning electron micrographs are presented depicting early stages in the diagenesis of framboidal iron sulfide.
Phosphate pumps and shuttles in the Black Sea
Phosphate distributions in oxic–anoxic ocean basins are related to distributions of total oxygen consumed (mainly from free oxygen, nitrate and sulphate) in the decomposition of organic matter1,2.
Microbial mediation of Mn(I1) and Co(I1) precipitation at the O,/H,S interfaces in two anoxic fjords1
We studied the potential for bacterial catalysis of Mn(II), Co(H), and Fe(III) precipitation at the 02/H2S interfaces in Saanich Inlet, British Columbia, and in Framvaren Fjord, Norway. In Saanich