a 50-meter nylon line stretched and anchored at both ends along 

 the transect path. Two one-meter long wooden dowels were attached 

 at one end with eye bolts to the line. Divers swam the length of 

 the nylon line with the dowels held at right angles to the line 

 and at the level of the base of the turtle grass. Echinoids 

 were counted as the dowels turned them over along the 50m transect. 

 Lyteahinus and Tripneustes , with similar ecological and morpho- 

 logical characteristics, were counted together and Diadema was 

 counted separately. 



PLANKTON TOWS 



Four plankton tows were taken monthly; two at Station 9 in the 



turning basin and two along the desalination plant sea wall. At 



both locations one tow was taken at 6 feet (1.8m) depth and another 



at 28 feet (8.5m). A 0.1m plankton net with 50 meshes per cm (125 



per inch) was towed 100 meters by a SCUBA diver, thus filtering 



10m of water. At the end of each tow the net was sealed off at 



depth and the sample transferred to a Whirl-Pak and preserved with 



alcohol. The entire sample was later reduced to 10 ml by allowing 



it to settle in a graduated cylinder for four hours and siphoning 



off the supernatant fluid. The remaining sample was then mixed thoroughly, 



sampled, and the plankters counted on a Palmer counting cell. Data 



were recorded as numbers of cells or zooplankters per m of original 



sample. 



To determine effects of effluent on plankton populations, the tows 

 at Station 9 were used as controls for the tows made in front of 

 the desalination plant. The two shallow tows and the two deep tows 

 were compared with each other and the number of plankters found at 

 the desalination plant expressed as percentages of the Station 9 tows. 

 Station 9 (600 meters south of the desalination plant) was similar, 

 topographically, to the canal in front of the plant discharge. Since 

 water from Station 9 generally moved into the harbor the plankton 

 population should have been similar at both locations. Differences 

 between Station 9 plankton populations and the canal were attributed 

 to effluent effects. Tows were made in front of the desalination 

 plant with effluent present and after the plant had been shut down 

 for several days for conformation of the similarity of plankton 

 populations. 



SETTLEMENT PANELS AND DIATOMETERS 



Wooden settlement panels and glass diatometers were placed at selected 

 stations in Safe Harbor and in the control area and recovered at 

 periods ranging from two weeks to two months. The panels were 

 settled by organisms which survived the effluent during larval. 



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