Ch. 6— Environmental Considerations » 241 



Photo credit: Barbara Hecker, Lamont-Doherty Geological Observatory 



Brittle stars and corals, shown here at 2,000-foot water depth, are two common kinds of animals living on hard substrates 



in the deep sea. 



acteristics of the phytoplankton. No other poten- 

 tial effects (including increased production due to 

 nutrient enrichment or heavy metal toxicity) could 

 be demonstrated.'" 



Application of the DOMES conclusions to the 

 crust mining scenario requires some modifications. 



'"U.S. Department of Commerce, Deep Seabed Mining, FinaJ 

 Programmatic Environmental Impact Statement. Minerals Manage- 

 ment Service, Draft Environmental Statement: Proposed Marine 

 Mineral Lease Sale in the Hawaiian Archipelago and Johnston Is- 

 land Exclusive Economic Zone, Honolulu, HI, (1987), p. 208. 



The crust mining surface plume will contain more 

 solids in less water than the nodule mining surface 

 plume, but the crust particles are larger and settle 

 out faster. Thus, the area of reduced primary prod- 

 uctivity probably would be approximately 50 per- 

 cent smaller than that predicted for the nodule sce- 

 nario, a very short-term localized impact. '' 



Bottom Plume. — A bottom plume would be 

 generated from the movement of the mining equip- 



"U.S. Department of the Interior, p. 208. 



