Rate and nature of infestation of a carbonate substratum by a boring alga

Iceland spar crystals, maintained in the shallow subtidal marine environment at Discovery Bay, Jamaica, become infested by the boring chlorophyte, Ostreobium sp. The exposed crystals were collected at intervals over a 257-day period; they showed the relationship between time and percentage infestation by surface area in the crystals to be asymptotic, with ≈ 100 % surface infestation 213 days after being placed in the sea. Initial infestation begins early (4–7 days), and proceeds slowly for the first 15 days; it then increases rapidly for the next 80 days and slows down after about 95 days.The crystallography of the substratum exercises strong control over filament orientation during initial infestation but this control decreases as the filament density increases.