FISHERY BULLETIN: VOL. 74, NO. 2 



Table l. — Dry weight in grams of material collected per square 

 centimeter of surface area from five artificial media exposed 

 at the near-surface level for four time periods. 



Table 2.— Density of the barnacle, Balanus crenatus, per 

 square centimeter of surface area collected from five artificial 

 media at three depths. 



79-day and the 101-day samples had removable 

 material weighing less than 0.01 g/cm^. Remov- 

 able material consisted primarily of diatoms, with 

 small deposits from flaking of the alloy surface. No 

 mussels, barnacles, or green algae were observed. 



STEEL.— After 41 days the dry weight of the 

 removable material was 0.15 g/cm^, after 58 days 

 0.26 g/cm2, after 79 days 0.23 g/cm^, and after 101 

 days 0.13 g/cm^. A high proportion of the remov- 

 able material was rust; biological accumulations 

 consisted of diatoms, barnacles, green algae, and 

 mussels. Balanus crenatus densities at the 1-m 

 depth ranged from 0.0 on day 41 to 0.3/cm2 on day 

 19. Balanus density at the 6. 1-m level ranged from 

 0.0 on day 41 to O.l/cm^ on day 58. No Balanus 

 were found at the 15.3-m level. 



PLEXIGLAS. — After 41 days the dry weight of 

 the removable material was 0.19 g/cm^, after 58 



days 0.09 g/cm^, after 79 days 0.08 g/cm^, and after 

 101 days 0.04 g/cm^. Removable material con- 

 sisted of diatoms, green algae, and barnacles. 

 Mussels were not observed on the Plexiglas media. 

 The density of Balanus crenatus at the 1-m level 

 ranged from 0.0 on day 41 to O.S/cm^ on day 79. At 

 the 6. 1-m \eve\ Balanus densities ranged from 0.0 

 on day 41 to 0.5/cm2 q^ day 79. No Balanus were 

 found at the 15.3-m level. 



WOOD.— After 41 days the dry weight of the 

 removable material was 0.13 g/cm^, after 58 days 

 0.09 g/cm2, after 79 days 0.07 g/cm^, and after 101 

 days 0.05 g/cm^. Removable material consisted 

 primarily of diatoms and barnacles with small 

 amounts of green algae. No mussels were found. 

 The density of Balanus crenatus at the 1-m level 

 ranged from 0.0 on day 41 to 0.9/cm2 on day 101. 

 Balanus density at the 6. 1-m level ranged from 0.0 

 on day 41 to 4.6/cm2 on day 79. Balanus density at 

 the 15.3-m level ranged from 0.0 on day 41 to 

 39/cm2 on day 19. Balanus achieved 100% of plate 

 coverage on day 79 at the 15.3-m level. No wood 

 borers were found at any level. 



CONCRETE.— After 41 days the weight of the 

 removable material was 0.12 g/cm^, after 58 days 

 0.07 g/cm2, after 79 days 0.05 g/cm^, and after 101 

 days 0.04 g/cm^. Removable material consisted of 

 diatoms, barnacles, mussels, and green algae. The 

 density of Balanus crenatus at the 1-m level 

 ranged from 0.0 on day 41 to 4.9/cm2 on day 79. 

 Balanus density at the 6. 1-m level ranged from 0.0 

 on day 41 to 1 1.3/cm2 on day 19. Balanus density at 

 the 15.3-m level ranged from 0.0 on day 41 to 

 64/cm2 on day 79. Balanus achieved 100% plate 

 coverage on day 79 at the 15.3-m level. Bay mus- 

 sels, Mytilus edulis, achieved a density of 0.4/cm2 

 at the 1-m level — none were found in the deeper 

 water samples. 



Intertidal Fouling 



The colonization of fouling organisms was ob- 

 served on concrete test slabs positioned at various 

 levels in the intertidal zone of Kiket Island. The 

 principal algae species colonizing the slabs were 

 Fucus distichus and Ulva lactuca. The dominant 

 animal species included the acorn barnacle, 

 Balanus glandula, and the bay mussel. A detailed 

 examination of the natural vertical and seasonal 

 distribution of the intertidal flora and fauna of 

 Kiket Island is presented by Houghton (1973). 



380 



