Wind-blown dry fungal spores and mycelial fragments from the nearest landmass or terrestrial run-off may find their way to the deep sea by hitching a ride on other sinking detrital particles. Once in the deep, they are affected by elevated hydrostatic pressure, low temperature and low nutrients. Effects of these on germination of spores from a few deep-sea Aspergillus isolates are examined. Spores from most of the fungi germinated under elevated hydrostatic pressure at 30 degrees C. The ambient temperature of the deep sea. Approx. 4-5 degrees C, was found to inhibit spore germination totally. Sediment extracts prepared in seawater promoted spore germination as did additions of dimethylsulfoxide and sucrose, but only at 30 degrees C/200 bar pressure and not at 4-5 degrees C. Heat shock of 15min at 50 degrees C helped in breaking the dormancy of the spores and induced germination at 5 degrees C at 1 bar pressure but not at 200 bar. More than 90% of the spores from several deep-sea Aspergillus isolates and the terrestrial isolate of Aspergillus terreus lost viability within 16–17 days of incubation at 5 degrees C/1 bar. About 2-3% remained viable for more than 3 months at 5 degrees C/1 bar. Mycelial fragments showed growth and biomass production under elevated pressure at 5 degrees C. These results indicate that building biomass under deep-sea conditions from spores is not a viable option for the deep-sea A. isolates. Mycelial fragments, on the other hand, are more likely to grow.