that was exposed at 295 feet (5 feet above bot- 

 tom) for 12 months off Fort. Lauderdale, FLa. 



O-20 Equipment Required for Obtaining 

 Fouling Observations. — The following equip- 

 ment and materials are required for obtaining 

 fouling observations : 



1. Test panels; 6 by 12 inches, composed of 

 1/4 -inch asbestos board and %-inch white pine 

 board, connected back to back. The asbestos 



?irovides a fibrous surface for the collection of 

 ouling organisms, and the pine board is an 

 ideal collector for marine borers. 



2. Polypropylene line; %- or %-inch diam- 

 eter or 14-inch wire rope. 



3. Shackles, swivels, wire clips, and plastic 

 sleeve insulatore. "Wlien attaching panels to steel 

 wire rope, insulators must be used. 



4. Modified split bolt connectors; brass, 

 S-1/0 and S— t/O, for attaching panels to line 

 or wire rope. 



5. Panel holder; six panels, with modified 

 split bolt connectors and brass panel bolts. 



6. Concrete anchors; 40 and 1,000 to 1,500 

 pounds with steel chain. 



7. Navy-type holding anchors; 15 and 65 

 pounds with chain. 



8. Toggle floats; 8-pound buoyancy plastic 

 and 500-pound buoyancy steel. 



9. Bathythermograph and Frautscliy water 

 sampling bottles, or Nansen bottles witli revers- 

 ing thermometers for obtaining water tempera- 

 tures and salinity samples. 



10. Plastic bags for storing and preserving 

 test panels. 



11. Ethyl alcohol (100 percent) for preserv- 

 ing organisms on test panels. 



12. Water sample bottles. 



0-21 Selection of Fouling Sites in a Geo- 

 graphic Area. — Observation sites ai-e selected 

 as close to shore as critical depths (50, 100, 300, 

 and 600 feet) will allow. The range of salinity 

 should be from 25-35 %g. Harbors and other 

 areas where polution levels are high are 

 avoided. Four test sites, whenever possible, are 

 selected in each geographic area (fig. 0-9) — one 

 shallow site (50 feet) and three deep sites (100, 

 300, and 600 feet) . Also, several control sites are 

 selected in the vicinity of the test sites. 



0-22 Planting the Fouling Arrays. — At each 

 site, obse^^'ations are obtained by planting ar- 

 rays of panels. The number of arrays at a site 

 and the number of panels per array depend on 

 the depth of water. On shallow water arrays 

 (50 feet), one panel on each array is always ex- 

 posed 5 feet above the bottom, and one is always 

 within 10 feet of the surface (fig. 0-9). Panels 

 are connected to tlie shallow water array line 

 with modified split-bolt connectors (fig. O-IO). 

 These arrays are planted in clusters of 15 at 



each site. The distance between arrays is ap- 

 proximately 10 meters. Shallow water arrays 

 with 40-pound concrete anchors usually are 

 planted from small vessels as they do not re- 

 quire boom or winch equipment. 



At each deep site, two deep water arrays 

 with 1,000- to 1,500-pound concrete anchors are 

 planted. The deep water arrays have clusters of 

 six panels at each of the standard intei"vals 

 shown in figure 0-9. 



At the time the arrays are planted, the follow- 

 ing information should be recorded for each 

 panel : Panel number, geographic area, site num- 

 ber, latitude and longitude, array identification, 

 location of panel on array, date panel was sub- 

 merged, and water depth (measured at time of 

 plant). In addition to the above information, 

 the water temperature and a salinity sample 

 from the submerged depth of each panel must be 

 obtained. A suggested format for recording ma- 

 rine fouling and boring test panel data is given 

 in figure 0-11. 



The water temperature can be obtained with 

 a BT (chapter C, Measuring Water Tempera- 

 ture and Depth with a Bathythermograph) or 

 revei-sing thennometers (chapter E, Takmg an 

 Oceanographic Station), and the salinity sam- 

 ple can be obtained with a Nansen bottle or other 

 suitable water sampling devices such as the 

 Frautschy bottle (fig. 0-12). Record the initial 

 water temperature in degrees Celsius or Fahren- 

 heit, and the initial salinity sample bottle num- 

 ber. For the shallow water arrays, usually only 

 a surface temperature and water sample are 

 obtained. 



Under remarks, enter navigation informa- 

 tion, e.g., fix on tower and lighthouse, electronic 

 navigation coordinates Red 653-Green 121, sea 

 and swell conditions, etc. Draw sketches as 

 required. 



0-23 Recovering the Test Panels.— Each 



month (on approximately the same day), the 

 sites are visited, and certain panels are removed 

 and in some instances replaced. SCUBA divere 

 are used to locate the toggle floats, connect lines 

 to the deep arrays, and in some cases, to remove 

 and replace panels down to the 100-foot level. 

 The shallow arrays can be hoisted aboard the 

 recovery vessel by hand for recovering the 

 panels. 



Two systems of test panel exposure are em- 

 ployed (fig. 0-13). Long-tei-ni (series I) panels 

 are exposed for 1 month and cmnulatively 

 longer periods up to 12 months. This type ex- 

 posure provides data on rates of organic pro- 

 duction and growth, periods of dormancy, and 

 progressive changes of communities. Short-term 

 (series II) panels are exposed for 1 -month in- 

 tervals and provide data on the seasonal settle- 

 ment of organisms. 



0-9 



