One of the better-known examples is the interannual variation in egg mortality and fisheries landings of Baltic cod in the Baltic. Spawning success of cod in the central Baltic is hindered by hypoxic and anoxic water below the halocline (70-80 m) where salinity is high enough to provide buoyancy for cod eggs (Nissling and Vallin, 1996, Cardinale and Modin, 1999, Koster et al., In the Western Atlantic, hypoxia appears to contribute to low per capita productivity and slow recovery of cod stocks in the Gulf of St. Lawrence (Dutil etal.,