TABLE 7 - HABITATS OF FOULING ORGANISMS 



Organism 



Depth (General 

 Maximum) (ft) 



Range of Ocean 



Hydroids 



Surface 



to bottom (8-900) 



All over 



Gooseneck Barnacles 



Surface 



to 500 ft (200) 



Open ocean only 



Mussels 



Surface 



to 100 ft (30-50) 



Shore to 30 miles 



Starfish 



Surface 



to 8,000 



All over 



Snails 



Surface 



to 10,000 



Especially in Pacific 



Bivalves 



Surface 



to 14,500 



Especially in Pacific 



Tube worms 



Surface 



to 16,500 



Coastal waters 



Sea Urchin 



Surface 



to 16,000 



All over 



Sponges 



Surface 



to 600 



Coastal waters 



Bryozoans 



Surface 



to 900 (600) 



All over (coastal waters) 



Tunicates 



Surface 



to 500 



All over 



Borers 



Surface 



to bottom (7,000) 



All over 



Jellyfish 



Surface 



to bottom 



All over 



Fungi 



Surface 



to 600 



All over 



Acorn Barnacle 



Surface 



to 500 (100) 



Coastal waters (all over) 



Fouling affects a structure in many ways, depending on its composition 

 and severity. Generally, effects of fouling are: (.1) increased weight (as 

 much as 20-25 lb/ft ) ; (2) increased drag, which strains mooring lines; 

 (3) increased cost and time for onsite modular assembly and disassembly; 

 and (A) increased corrosion and deterioration (not only the formation of 

 metal oxides, but flaking or powdering of concrete). Many of the side 

 effects of fouling on concrete surfaces could be eliminated by paint films 

 properly applied and of sufficient thickness to reduce porosity. Paint 

 systems composed of very thick (8- to 12-mil) antifouling paint films 



applied on zinc and copper sprayed base coatings have protected many dif- 



7 6 

 ferent metals in deep waters. Along the surface in the middle of the 



Atlantic Ocean, toxic surfaces remained fouling-free for longer periods of 



time than those close to shore, ^^ It is also possible that the leaching 



rates for antifouling paints may decrease with increasing depths. However, 



30 



