The action of anerobic bacteria has caused a large amount of corrosion to ships at great depth. Black iron (II) Sulfide forms on steel along with iron (II) hydroxide which, if ther is some oxyen, further oxidation can cause rust
The chemistry of this is below:
The sulfate reducing bacterium sporovibrio desulfuricans use sulfate ions from water, instead of oxygen for respiration. The SO42- are reduced, by anerobic bacteria first to sulfur then to the S2- ion
o SO42(aq) * S(s) * S2-(aq)
Metals such as iron can provide electrons for this process
o Fe(s) * Fe2+ + 2e
Black metal sulfides can form ,staining the artefacts from the wreck
o S2- + Fe2+ * FeS(s)
Metallic irons such as iron ions can also form from reaction of hydrogen ions with the metal
o Fe(s) + 2H+ --> Fe2+ + H2(g)
Iron ions can also react with water to form iron (II) hydroxide which can be further oxidised to rust, if there is any oxygen present (maybe oxygen rich water from the poles coming in by currents)
o Fe2+ + 2H2O * Fe(OH)2 (s) + 2H+
oh, the boxes mean arrows, hope u can comprehend it i dont type too wel