Abstract The effect of primary treated sewage on the distribution and abundance of microfauna found associated with three species of algae, characteristic of the low, mid and high intertidal, was studied. The results show that the sewage effluent effects thesdistribution of microfauna most srtongly in Prionitis lanceolata and Corralina vancouveriensus, algae representative of mid and low intertidal species, Microfauna associated with Endocladia muricata, the representative alga of the high intertidal, was effected only in the immediate region of the outfall. Information from current studies and chemical-physical assays in the study area allowed a hypothesis of effluent dispersal and effect to be made. Certain species, by their presence or absence on algae in the immediate outfall area, seem to be possible indicators of marine pollution. 55 Introduction The effects of sewage effluents on the marine environ- ment are not well understood. While fresh water and estuarine pollution have been rigorously studied, (Jones, 1964; Ingram, Mackenthum, Bartsch, 1966 ), the marine situation has been sorely neglected. A major reason for this has been the difficulty in isolating sewage effects in a complicated marine environment. At the present time local and State Health Agencies have been relegated to using coliform bacteria counts as the only standard measure of pollution. Experience has shown, however, that this method is unsatisfactory (Carter, Carpenter, Whaley, 1967; Nuebaum, Garver, 1955 ). A more accurate and substantial indicator of marine pollution is needed. It was with this problem in mind that the present study was undertaken. Pacific Grove, California, discharges approximately 1.6 million gallons of primary treated sewage daily from an outfall located on Point Pinos within the boundaries of the Pt. Pinos Lighthouse Reservation, a Marine Life Preserve. The end of the outfall is located approximately 160 meters from the base of the point in a rocky intertidal area on the south side, and lies one foot below mean lower low water (-1.0 ft.) in a region that recieves heavy surf. Studies carried out during the Spring of 1970 at the Hopkins Marine Station revealed significant differences in macrofaunal and floral distribution between the immediate outfall area and other, less polluted regions of the point. 1 2. However, these overt differences were limited to a small area of no more than 20 meters radius from the end of the pipe. A search for an indicator of more widespread and subtle effects suggested the efficacy of studying micro- faunal distribution in the Pt. Pinos area. Might not microfaunal distributions and associations reflect subtle differences in the environment not mirrored by by macro- fauna? Specifically, might algae-microfaunal associations, which are numerous and constant for a given defined region (Glynn, 1963 ) serve as an indicator of marine pollution? I decided to study the distribution of microfauna on three species of algae characteristic of low (-1.0 to +1.0 ft.), medium (+1.0 to +3.0 ft.) and high (+3.0 to 15.0 ft.) tidal heights in order to determine the effects of the effluent as well as the role played by tidal height. Material and Methods Preliminary information on currents and physical- chemical attributes of the study area was obtained from investigations made in the Spring of 1970 at the Hopkins Marine Station (Anon, 1970). Samples of algae were taken from around the point at convenient locations. All sample locations were resampled one to three times. The algae chosen were all red algae, the most extensive group present in this area. Endocladia muricata was chosen as being the representative alga of the high intertidal. (+3.0 to +5.0 ft.). The sample sites ranged from +3.0 to +5.0 feet, with all samples being taken from horizontal surfaces. All sample sites were equally exposed to high tide wave action. Figure 2 shows the location of the Endocladia sample sites. Replicate samples are grouped into area for convenience and future reference. No Endocladia samples were taken from Area l to Area 2 due to the fact that no Endocladia could be found in this area. Whether or not the absence of this alga can be attributed to the effects of the ef- fluent is unclear. Prionitis lanceolata was chosen as being a representa- tive alga of the mid-intertidal. (+1.0 to +3.0 ft.) This species was the only macroalga present in the im- mediate outfall area. Figure 3 shows the location of the Prionitis sample sites, which range from 0.0 to 14.5 feet. Exposure ranges from semi-protected on the north side of the point to full wave shock in areas 3-8. Corralina vancouveriensus was chosen as a representative alga of the low intertidal. (-1.0 to +1.0 ft.) Sample sites range from -1.0 to +1.0 feet. Figure 4 shows the location of these sample sites, all of which were open to direct wave action at low tide. Due to adverse conditions however, fewer Corralina samples were collected. Each of these algae are perennials, and as such can be expected to have a permanent population of associated microfauna (Abbott, 1970). 18. Wave action ranged from slight in areas 1, 2 and 3, to heavy in areas 4-9 (Figure 3). Samples collected from the west end of the point, area 10, were protected from wave action but experienced a strong surge on both rising and falling tides. Samples from areas 11, 12 and 13 recieved a moderate amount of wave action. Sites further east along the north side of the point, area 12, recieved only light surf (Figure 2). Collections were made at periods of low tide, employing a chisel to remove the alga and it's holdfast from the rocks. These were placed in plastic bags and brought back to the lab for analysis. From-5.0 to 20.0 grams of Endocladia and Corralina were collected on each occasion except where not available in areas 1 and 2. In those cases the algae available was taken. In the case of Prionitis samples one entire plant and holdfast was taken for each sample. Samples were taken from ten areas each time, with a 2-4 day interim between replicates. The samples were analyzed by placing them in finger bowls with 5% ethanol in distilled water and removing the organisms under a dissecting scope. Organisms were identified as closely as possible then preserved in 80% ethanol for further reference. The algae were dried for-24 hours at 60 C in a drying oven and weighed. The Simpson and Shannon-Weiner indices were used to compute the species diversity for each sample. The 15 Simpson index is given by the formula where Nis the total number D- N(N-1 of animals found En(n-1) and nis the number of individuals of each species. This index corresponds to the number of randomly selected pairs of individuals that must be drawn from a community in order to have an even chance of obtaining a pair with both individuals of the same species. The Shannon-Weiner index is based on the Shannon-Weiner function from the field of information theory. As a diversity index for biotic communities the function describes the average degree of uncertainty of predicting the species of an individual picked at random from the community. It is given by the formula D= 3.219 (19510 -1Enlog 10n) where N and nare the same as for the Simpson index (Cox, 1967). Neither index is free from sample size bias, but both are equally affected. It must be kept in mind, however, that I am applying these indices to samples of different sizes. The Simpson index would be expected to give low results for samples containing one species in great excess of the others. 66 6. Results Table l shows the results of a one day chemical study made in the Pt. Pinos area. This table also includes information on temperature, pH and dissolved oxygen levels determined at both high and low tides. It can be seen from the low tide figures that a gradient exists on either side of the outfall, which suggests that areas 2-5 in Figure 2 may be the most effected by the effluent. Note that the differencesiin physical- chemical parameters at high tide all but disappear. This suggests that at high tide the effluent is diluted considerably with fresh seawater. Figure 1 shows a composite of the local currents at both high and low tides. This data appears to account for the distribution of the effluent around the point. Coupling the information from Table 1 and Figure 1 one would expect to find damage in areas 3, 4, 6 and 11 in Figure 3, as well as areas in the immediate vicinity of the outfall. As mentioned earlier, the distribution of macrofauna and flora in the immediate outfall area shows a marked change from other areas of the point. The numbers of algal and invertebrate species present is severely reduced, and many of those organisms whish are present appear sickly and unhealthy. Endocladia: Table 2 shows the tabulated data for samples of Endocladia. Note the variation in the total number of taxonomic groups in relation to distance from the outfall. Also of some significance is the mean number 16 of animals per gram dry weight for the replicate areas and the ranges for the diversity indices at increased distances from the outfall. Table 3 shows the species composition of the animals found. Species seem to be rather evenly distributed, except for the Amphipoda, which do not appear in samples taken in the immediate area of the outfall (10 meters radius). Figure 5 illus- trates the distribution by phyla. Again, other than the Arthropoda, there appears to be a relatively even dis- tribution. A plot of the mean diversity indices and mean numbers of taxonomic groups for the replicate areas is shown in Figure 6, and these curves show dips at the outfall and at area 9 across the point from the outfall. Prionitis: Table 4 presents the tabulated data for Prionitis. Again, note the changes in the total number of taxonomic groups present and the diversity indices at sites around the point. Area 9 shows a very definite cut-off line where both of these parametersgo from low values to quite high values. It may be that these figures reflect the radius of effect of the effluent for this species of alga and it's microfauna. Table 5 demonstrates the species composition of the samples. It appears from this table that Nereid worms, Amphipods and Copepods by their absence, and Tethymia aptena, a fly larvae, by it's presence may serve as pollution indicators. The distribution by phyla (Figure 7) suggests that the Arthropods, Annelids and Molluscs are effected in the outfall area within a radius of 25 meters. Figure 8 represents a plot of the mean diversity indices and numbers of taxonomic groups as a function of distance from theoutfall. Note the strong dip in the region of the outfall, and the smaller dip in area 11. Corralina: The tabulated data for Corralina is shown in Täbles6. Once again, note the changes in total number of taxonomic groups and diversity indices in sample sites near and away from the outfall. Also, the numbers of orga- nisms per gram dry weight shows a drop in samples taken in the outfall area. Table 7 demonstrates the species compo- sition for these samples. Note the marked differences in the occurence of the Amphipods, Puggetia and the tunicates. Also, to a lesser extent, Pagurus, Mohnia and Tricolia show similar trends. Figure 9 shows the distribution by phyla for the Corralina samples. Only the Arthropoda seem to show any kind of gradient through the outfall area. A plot of the mean number of taxonomic groups and diversity indices against the areas sampled is shown in Figure 10. Specific indicators of pollution: Figure 11 shows a listing of the species found associated with Corralina (top) and Prionitis (bottom) which appear to show the greatest variation in abundance as related to the presence of the out- fall. Of the species found with Endocladia, only the Amphipods showed distributional effects related to the outfall area. 16. 9. Discussion The results indicate that the primary treated effluent is causing changes in the distribution of algal microfauna in the Pt. Pinos area. This is shown by the fact that gra- dients in microfaunal populations through the outfall area cor- respond with chemical gradients produced by the dispersed effluent. Current study results show how the effluent may be dispersed in this manner. That a change in the microfauna exists is shown by var- iations in diversity indices, total number of taxonomic groups and mean numbers of animals per gram dry weight found in samples within the area influenced by the effluent. These variations are in full accord with the dispersal pattern of the effluent material. In two species, Prionitis and Corralina, certain species found in other areas completely disappear from the samples taken in the vicinity of the out- fall, suggesting that they might be potential indicator species. The effect of tidal height is important. Endocladia showed radical variations in the immediate outfall area, but at greater distances seemed relatively unaffected. However, it does seem that at high tide contaminated water crosses the point and effects the community on the north side. This again is suggested by the pattern of effluent movement at high tide. Prionitis showed a marked effect in the outfall area, with the influence of the sewage effluent apparently extending 10. farther to the east and west than in Endocladia. Only a slight effect is observed in Prionitis across the point from the outfall. As the primaryly fresh water effluent wouls tend to float on the surface, it may be that at high tide the water crossing the point affects only the higher intertidal species such as Endocladia. When this water cros- sing the point encounters incoming water on the north side of the point, its movement may be slowed to the point where heavier materials in the effluent may settle out. Thus while the mid-intertidal may not be effected, the material settling out may effect the low intertidal, as observed below with Corralina. Corralina shows broad-based effects extending in both directions from the outfall, with a slight effect seen in the area directly across the point from the outfall. From these results it seems that Endocladia is only subjected to the effects of the sewage at high tides, when the effluent is most dilute (Table 1). Also, at high tide polluted water crosses the point and apparently damages the communities there in a limited area, This is in accord with the earlier predictions made on the basis of chemical and current studies. Prionitis is subjected to effluent laden waters on rising, falling and during high tides. Corralina is exposed to strongly polluted waters only at very low tides! At other times the polluted water covering this alga are probably well diluted. The most strongly polluted water would at all times be found on the surface due to the fresh water nature of the effluent. Within a radius of 50 meters from the outfall damage 162 11. appears to be noticeable. Outside of this area, variations in the parameters measured cannot be attributed solely to the presence of effluent because of natural variation. However, sewage effluent may be contributing to some of the differences observed. Mid-intertidal and low intertidal algae and microfauna seem to be the most strongly effected, with high intertidal species effected but slightly. It also appears that certain species of animals, notably the Amphipods, Copepods, Pugettia, Nereid worms, Tricolia, Mohnia and Barleeia by their absence and Tethymia aptena, by its presence on the effected algae may serve as specific indicators of pollution. More research concerning the distribution of these species in polluted waters may prove their usefulness to field workers looking for a criterion of marine pollution. A specific ecological survey, as presented here, can be usefull in showing the extent and severity of damage in polluted areas:. However, such a study demands considerable time and effort on the part of the investigator. This approach has provided insights into possible specific indicators of pollution, which may be usefull tools in combating the degredation of our environment. Acknovledgments: I wish to gratefully acknowledge the assistance of Dr. Welton L. Lee of the Hopkins Marine Station in the preparation and critical editing of this paper. This project was supported in part by the National Science Foundation, Grant No. CY-7288. 66 Literature Cited Abott. 1. A. 1970. Personal Comunication. Sartsch, A. F., W. M. Ingram, K.M. Nackenthum. 1966. Biological Field Investigative Data for Water Pollution Surveys. U. S. Department of the Federal Water Pollution Control Interior. Administration. Carter, H. H., J. Hm Carpenter., R. C. Whaley. 1967. The Bactericidal Effect of Seawater Under Natural Conditions. Jour. Water Pollution Control Federation. 1967. Laboratory Manual of General Cox, G. W. Ecology. Brown, Dubuque, Iowa. 116-119. Glynn, P. W. 1963. Ecological studies on the Endocladia muricata- Balanus glandula association in the inter tidal zone in Monterey Bay, California. Ph. D. Thesis. Beaufortia, Amsterdam. 1964. Fish and River Pollution. Jones, J. R. E. Butterworth's, London. 1955. Survival of Coliform Nuebaum, I., R. M. Garver. Organisms in Pacific Ocean Coastal Waters. Sewage and Industrial Wastes. Anon. 1970. Unp. lished Report of the Undergraduate Research Participation Program, Hopkins Marine Station, April 1970. Table 1. Chemical-physical attributes of the study area, Pt. Pinos, Monterey, California. Values for low and high tides, May 22, 1970. Station 16 taken at the Hopkins Marine Station represents the attributes of normal seawater. Station Salinity Temp. pH PO, Ne, D.09 128 asl tgafL 1/2 Logpl Eow Tide 33.74 10.7 7.76 .088 5.76 3.39 33.75 10.5 7.81 6.27 .058 6.66 33.66 7.88 10.2 5.00 .023 6.80 0.98 76 6.61 115 2.0 19.2 6.83 .115 19. 6.71 2.4 110 091 22.74 62 153 .274 7.09 2.8 16. 32.29 26 7.58 .038 11.6 2.0 .091 30.39 12.4 30 7.62 .153 .183 3.3 33.86 274 7.80 3.00 .004 11.0 3.0 10 33.95 7.86 10.5 2.00 .027 7.2 5.00 33.45 11 .023 6.8 7.88 11.2 33.45 12 10.8 7.89 2.00 023 6.8 13 33.98 004 11.6 7.52 3.00 7.2 14 33.86 .073 11.1 7.59 4.00 33.96 15 11.8 7.71 1.00 .024 7.3 16 33.97 .027 12.4 8.03 .091 1.00 High Tide 33.50 13.3 6.00 .065 8.12 11.2 411 33.29 11.5 8.06 6.00 .073 8.4 365 33.54 7.00 .096 .548 8.01 31.04 29 12.3 7.79 7.0 .183 .092 31.14 29 088 11.8 6.9 .046 7.80 31.32 .188 .594 12.0 6.8 7.81 31.36 157 27 7.81 411 33.54 11.0 7.90 7.6 .365 21 .131 10 33.73 11.5 8.05 6.00 457 .042 9.2 33.69 8.26 8.5 365 11 11.3 3.00 .042 12 10.9 7.8 .320 33.81 8.01 3.00 .050 13 33.95 8.38 11.4 .040 7.9 .228 2.00 14 33.70 8.22 .046 3.00 061 8.2 12.1 33.75 15 12.7 .050 .365 8.51 1.00 8.1 16 33.66 091 12.4 8.21 0.90 .015 Sample Station Locations O 2 ( (8 61 Outfall 9 -Hopkinss Marine Station (0 C12 Aom 11 170 Fig.1. Current systems in the Pt. Pinos Area, Monterey, California. Composite of flourescein dye and drift bottle studies of nearshore currents in and about Pt. Pinos during the Spring of 1970. The stipled area represents the visible sewage field. Arrows indicate the direction and relative strength of the current systems studied. Results of more recent studies concurrent with this investigation suggested that these patterns are similar to those prevailing during this study. 8 de fed. 42. Nrde bol ti 99 Ho Te uy 2 O Bint fhes 11 . Fig. 2. Location of Endocladia muricata sample sites around Pt. Pinos, Monterey, California. Letter prefixes indicate samples taken on the same day. Replicate samples are grouped inte areas. Scale: 1 inch- 16 meters. CHANT stcnor Net AREA 48 S — N H6 15 16 c9 Lade fod d2 o c8 3 Orde hol i 52 12 ourart 0 18 s 19- 18 19 ARIA 08 36 -D 16 19— O 110 —/ 3 12 8. Aeta ert Hes AREA ARLA 110 10 /. 1 2o Fig. 3. Location of Prionitis lanceolata sample sites, around Pt. Pinos, Monterey, California. Letter prefixes indicate samples taken on the same day. Replicate samples are grouped into areas Scale: 1 inch - 16 meters. CROSS CHAN INCH ata Bint fos 176 2o AREA AREA AREA 67 15 66 Iide sodl 42 482 —A6 38 65 a Orde kel 41 Q 8 s XAS 17 64 AL o -A16 + C o -65 as AS S Ata 61 A13 —2 A 7 e —41 + 4 816 ++ o 81 510 e O —610 AREA + Fig. 4. Location of Corralina vancouverensius sample sites around Pt. Pinos, Monterey, California. Letter prefixes indicate samples taken on the same day. Replicate samples are grouped into areas. Scale: 1 inch - 16 meters. CHAMPION ROSS SECTION AREA 2 28 5. AREA 0 ma k7 Vde fod d2 s ke de kol. 41 n 13 K2 14 OUAL Zu ka x3 195 50 o 110 0 H 2U 00 4 AREA VI M5 Bint flros AREA 2 7e Table 2. Tabulated data for Endocladia muricata samples. HI 11 J1 DI1 OUTFALL H2 12 J2 67 13 C13 H3 J3 H4 14 C8 H5 15 C10 J4 5 Hf. E 5 88 82 82 69 10 10 10 11 11 12.6 12.6 12.6 16 21 19 22 26 28 31 2.99 2.92 2.29 4.0 3.15 1.24 3.6 3.08 2.26 5.20 3.52 3.85 3.640 3.125 3.4 6.74 2.51 3.8 4.9 143 39 16 265 28 26 82 62 28 197 117 57 84 85 252 1138 84 188 74 47.83 13.8 6.99 66.25 8.9 20.93 22.75 20.13 12.38 37.88 33.24 14.82 23.1 27.2 75.74 20.47 33.43 49.47 15.1 8 3 5 7 12 8 9 10 10 11 15 33.72 18.18 24.58 42.2 26.6 3.71 2.19 6.66 7.529 1.79 2.12 2.99 3.27 3.35 3.60 2.10 5.27 2.56 3.98 4.81 4.22 4.19 3.79 4.29 2.2 1.6 2.5 2.1 1.02 0.99 1.87 1.98 2.3 5.1 1.4 2.4 1.9 2.28 2.68 2.41 2.37 2.37 2.57 10 11 12 H6 J5 16 C19 J6 H7 17 D8 H8 18 J7 38 19 D16 H9 J9 110 D9 J10 H1O 2 Hf. E ae 46 47 47 47 84 84 84 85 111 111 111 115 115 125 130 145 148 148 185 188 5 5.86 4.88 2.73 5.8 3.35 2.87 2.8 5.8 3.91 5.04 3.27 3.28 2.9 5.59 2.9 3.07 3.3 5.3 4.42 4.78 133 153 124 520 66 142 109 280 1.71 106 95 63 51 175 88 103 60 180 263 164 22.7 31.34 45.5 89.66 19.73 48.34 38.9 48.29 18.14 21.04 29.09 19.23 17.6 31.30 65.77 33.5 18.43 33.96 59.2 34.54 12 17 13 12 8 14 10 18 10 12 14 11 5 1) 47.31 38.82 22.77 18.4 48.53 28.63 46.87 6 2.58 4.14 3.47 3.10 5.01 2.95 6.08 4.22 1.97 5.53 3.54 1.74 2.85 3.47 4.78 2.54 4.79 4.39 1.45 1.97 2.4 3.78 2.1 2.63 1.95 2.92 2.5 1.62 2.8 2.0 1.27 1.73 2.2 2.7 0.81 2.73 2.5 0.98 1.3 Table 3. Species composition for Endocladia muricata samples. Numbers are numbers of individuals per 100 grams dry weight of algae. Species occuring in only one sample are omitted. 8 2 — 25 HI 11 JI 218 50 25 DII OUTFALL- H2 12 138 J2 C7 32 13 C13 192 115 28 H3 J3 52 H4 137 82 14 736 1029 441 C8 118 44 H5 15 1115 C10 447 131 J4 489 H6 102 51 J5 1167 16 211 C19 293 153 149 J6 69 69 H7 714 17 75 D8 34 127 H8 153 18 654 J7 1132 J8 1434 19 172 161 D16 373 149 H9 J9 1659 242 110 1188 D9 320 J10 157 63 HIO 21 o 84 O 0 — 6 1 +0 o. — 91 c0 11 85 1m a 11 T o 150 1000 750 35 87 25 1880 1125 L-------------- 640 80 80 1110 27 970 162 660 44 44 88 288 1920 19 19 19 850 260 286 208 27 27 1370 54 8960 64 2558 647 29 740 489 59 797 597 39 2110 184 2040 407 520 17 17 40 620 40 20 1090 119 39 39 2590 68 51 597 537 2620 34 802 710 71 1107 142 1720 1155 17 1280 25 496 19 920 30 860 68 1340 536 17 2240 32 224 620 65 32 760 30 121 121 940 37 18 94 49 680 22 22 22 420 147 21 183 E — HI 70 11 43 J1 375 DII OUTFALL- 78 H2 12 277 J2 194 C7 88 13 C13 461 38 312 183 114 302 14 128 C8 441 74 H5 44 239 15 473 C10 J4 101 H6 51 J5 348 16 543 C19 482 J6 119 H7 523 17 428 D8 224 H8 101 102 238 18 J7 214 J8 61 68 19 89 D16 H9 672 683 90 10 264 J10 112 126 H1O a 35 --------- 27 230 128 176 52 20 17 20 39 224 34 71 68 79 373 149 60 21 8 35 44 32 39 52 543 107 17 99 74 30 1525 50 125 35 886 319 174 86 23125 ----------------------. 175 1774 665 519 129 176 44 346 153 2130 28 468 302 672 1705 500 578 478 1263 210 163 40 119 1313 737 40 81 119 438 4275 775 328 89 802 35 35 1068 102 79 257 520 91 274 30 91 586 858 1868 149 585 242 433 37 4852 2632 318 99 55 80 28 64 29 40 17 79 29 35 34 53 74 25 44 26 39 20 34 20 39 119 34 25 30 43 ---- 80 27 14 35 30 17 ---- 17 35 74 Figure 5. Distribution by phyla for Endocladia muricata samples. 1 3 8 5 8 16A Ka L 5 H10 110 09 110 19 H9 D 16 19 18 17 48 D 8 H7 16 c 15 He c 10 HA N3 c 13 c7 12 H 2 D11 J1 11 H1 LE L a SON Figure 6. Plot of mean diversity indices and mean number of taxonomic groups against the sample areas for Endocladia muricata. Solid line shows Simpson index, broken line shows Shannon¬ Weiner index. 12 13- 12- 10 OUTFAL AREA 2 10 12 »1 2 r 2 2 TAble 4. Tabulated data for Prionitis lanceolata samples. A13 FI G1 Al7 G2 A7 F2 A2 A15 A8 G3 F6 A16 A5 A12 G4 OUTFALL F7 A19 A9 5 o 88 91 91 90 83 69 66 60 20 16 12 2.5 2.5 2.5 1.3 2.5 5.4 E 11.3 6.31 7.17 13.4 9.32 12.1 11.65 10.2 9.9 10.6 7.91 9.26 10.1 10.2 10.0 7.37 9.99 10.4 7.0 424 1172 68 60 16 260 304 22 27 86 105 0.354 67.22 163.46 5.07 6.49 1.32 22.32 0.88 0.61 0.66 9.48 32.84 0.09 2.16 2.70 11.6 10.5 0.3 0.86 2 11 8 6 5 2 13 0.35 60.55 8.17 3.58 16.46 5.49 3.89 2.0 2.83 2.37 1.81 1.43 2.67 1.08 3.6 1.5 4.2 2.09 1.03 0.0 1.18 1.17 1.3 1.1 1.0 1.5 2 0.8112 1.94 1.56 1.41 0.98 3.9999 0.3138 1.6577 0.6500 1.5566 1.46 0.1117 0.0 0.4394 0.4550 0.8126 0.3677 0.0 0.6500 A1O F3 G5 A6 B2 G6 F4 G7 10 F5 B6 G8 11 F8 B7 B16 12 F9 G9 Bl1 O3 F10 G10 . 2 12.3 12.2 17 24 26 32 35 51 54 57 84 87 87 115 115 115 146 146 146 16.3 7.6 8.54 8.1 10.4 7.24 3.99 8.59 7.87 14.6 5.89 8.9 9.4 12:2 6.58 5.98 10.9 8.9 4.96 55 89 20 15 294 181 340 313 141 245 174 18 32 142 174 28 205 96 0.184 7.20 10.43 2.47 1.44 40.61 45.3 39.57 39.77 9.83 41.53 19.55 1.802 2.6 21.58 29.06 2.57 23.03 19.34 2 12 11 13 12 10 12 12 10 11 10 10 15 5.94 22.45 29.72 20.96 17.74 14.98 1.0 1.2 2.54 1.0 1.59 2.03 1.45 1.81 1.96 3.8 1.98 3.54 4.94 2.72 2.99 2.42 8.6 4.14 3.05 4 0.0 0.4394 1.78 0.0 1.64 1.69 1.15 1.61 1.21 2.24 1.74 1.74 2.89 3.37 2.09 1.73 2.93 3.14 2.14 ( Table 5. Species composition of Prionitis samples. Numbers are numbers of individuals per 100 grams dry weight of algae. Species occuring in only one sample are omitted. 72 Al3 FI G1 Al7 G2 A7 F2 A2 A15 A8 G3 F6 A16 A5 Al2 G4 F7 A19 A9 A1O F3 G5 A6 B2 G6 F4 G7 F5 B6 G8 F8 B7 B16 F9 G9 BII F1O G10 18 22 25 10 25 11 10 14 24 36 24 15 68 22 112 196 186 25 10 10 47 10 14 210 300 24 304 323 34 32 24 60 55 420 10 96 25 20 140 84 24 68 32 30 17 11 60 27 10 24 80 24 24 27 28 11 17 11 22 24 16 240 32 33 80 144 22 48 21 24 48 24 13 12 13 20 14 14 17 20 16 238 12 28 22 13 17 33 11 64 48 16 45 60 3170 8370 3730 5400 83 2146 500 500 200 6300 3241 1960 2500 1020 1000 32 70 18 660 600 250 12 3750 12 1270 510 562 24 1130 835 1120 1010 12 11 39 22 127 197 52 20 Al3 Fl G1 A17 G2 A7 F2 A8 G3 F6 A16 OUTFALL A5 A12 G4 F7 A19 A9 A1O F3 G5 A6 B2 G6 F4 G7 F5 B6 G8 F8 B7 B16 F9 G9 BI1 F1O G1O A2 A15 84 20 310 400 33 80 45 60 130 120 440 80 170 250 50 160 330 27 560 200 60 312 22 80 27 122 84 80 165 30 170 88 10 90 360 40 75 20 26 10 14 12 52 14 22 40 17 11 60 12 10 11 oa a- 0 C 1560 6080 130 300 120 280 275 2500 150 2500 1040 30 64 375 165 18 330 75 54 — 33 30 1430 66 70 360 30 15 17 36 20 10 70 15 a 1 15 20 — Figure 7. Distribution by phyla for Prionitis lanceolata samples. 8 — e0 S 178 610 10 511 6 9 F 9 8 16 8 7 F 8 68 B 6 F 5 67 F 4 66 82 46 65 F 3 A 10 A 9 A 19 F 7 6 4 A12 45 A16 F 6 6 3 A 8 A15 42 12 A 7 62 A17 F1 A 13 L — a L o e 6A7SON Figure 8. Plot of mean diversity indices and mean number of taxonomic groups against sample areas of Prionitis lanceolata. Solid line shows Simpson index, broken line shows Shannon-Weiner index. 2 Ix a AREA 12- 10 5 4- 2- 4 2 2 3 5 3 9 10 11 12 13 81 2 OUT FALL 76 Table 6. Tabulated data for Corralina vancouveriensus samples. LI K1 L2 K3 K4 MI OUTFALL¬ L4 K2 L3 M2 L5 K5 K6 M3 M4 K7 M5 K8 K9 L9 K1O LIO 10 11 S HE. 8.96 82 82 10.751 11.495 60 60 7.025 18 19.715 18 10.46 ---- --------. 2.5 7.85 2.5 12.462 7.08 11 8.32 11 13 4.55 13 11.98 10.90 22 9.63 22 54 12.93 54 15.216 84 15.42 17.18 84 115 11.61 115 13.05 146 8.06 146 10.62 J. —— 2 264 29.46 27.99 301 10.61 122 16.79 118 75 3.80 73 6.98 ------------- 73 9.3 47 3.77 115 16.2 94 11.29 26.59 121 73 6.09 8.89 97 87 9.03 95 7.347 97 6.37 120 7.78 119 6.9 9.39 109 221 16.93 90 11.16 14.49 154 18 10 11 8 8 11 12 13 11 14 12 12 14 17 18 15 5 6 7.88 28.78 2.72 13.68 5.32 3.87 5.38 2.13 2.06 -------------------- 6.53 2.05 2.30 2.48 13.53 3.05 16.34 5.42 2.04 8.96 3.29 2.94 6.89 3.29 3.41 77.34 2.42 2.37 3.60 13.16 5.87 3.06 13.83 3.49 27 4.71 1.97 2.58 2.33 1.63 1.59 ——------- 1.54 1.71 1.87 2.08 3.85 1.6 2.24 2.18 2.3 2.37 2.6 2.0 2.45 3.61 2.54 2.53 00 Table 7. Species composition for Oorralina vancouveriensus samples. Numbers are numbers of individuals per 100 grams dry weight algae. Species occuring in only one sample are omitted. 1— RERRRERE: BGSOERÖSEE 4 FNU POUFFPOUUPPOOONO JNOOOUNOUEDOONE Jooou ooooo oo PN 8 88 OUN 8 OPUSPGGOOSGOENEUEBOGE o OOSNOUONOOGIOGOONU — oооoоöL O GPUOF POONEPOUEOUUP DNIOGUNSO Sc 80 S 0 S 0 S 8 E 8 P S GO SE 50 SS 8p;o 00 SAMPLE SITE NEMERTEA ANNELIDA Unidentified Nereidae Syllidae Terebellidae Spionidae Cirratulidae Phyllodocidae Ampharetidae Phragmatopoma spp. PORIFERA Sponge. % bulk of sample Tunicate Unidentified. % bulk of sample. Polydontidae Oligochaeta 203 XRER AXPEER PPOOOGSPOOGGSOSRRBTÖSEE JE O0 oc o-8 S oooo Go 8 SGo6 o oooouu S O 50 50 ooo 5 S 5 — — ONOE O- -OPOC UONQN Foo oonu ONO UOOOPP NN So SS 85 8800 o N ooo GN 50 20 SAMPLE SITE ARTHROPODA Isopoda Dynamene Cirolina harfordii Amphi poda Oligochinus Hyalidae spp Chellifera Pagurapsuedes laevis Eucarida Pugettia spp. Pagurus samuelis Tethymia aptena (fly larvae) MOLLUSCA Barleeia spp. Mohnia spp. Tricolia spp. Lacuna spp. Volutomitra spp. Turritolopsis spp. Mytilus spp. ECHINODERMATA Pisaster spp. Figure 9. Distribution by phyla for Corralina vancouveriensus samples. L 1 15 0 + 10 1 L 908 K 10 19 K 9 K 8 K 7 m 4 M3 K6 14 M K4 K 3 K 1 11 LL LE a Figure 10. Plot of mean diversity indices and mean number of taxonomic groups against sample areas for Corralina vancouveriensus. Solid line shews Simpson index, broken line shows Shannon-Weiner index. 206 I ARE 3- 2 4 5 6 10 1 2 20 a 1X 4 12- 2 OUTFALL 0 Figure 11. Distribution of speies that show the most variation found associated with Corralina vancouveriensus (top) and Prionitis lanceolata (bottom). Circle indicates presence of species at sample site. Heavy double line represents the location of the outfall. 0 — 2 O — L 0 0