In addition to the species listed below, a number of other organisms were occasionally found on the tires but were not counted. These include the nudibranchs Phidiana crassicornis, Doridella steinbergae and Flabellina sp.; the goose barnacle Pollicipes polymerus; the decorator crab Oregonia gracilis; the Cancer crab C. oregonensis; the green sea urchin Strogylocentrotus droebachiensis; the sea cucumber Eupentacta quinquesemita; the solitary ascidian Styela montereyensis; and innumerable tiny arthropods.

Key:
     + : species was present but not counted
    ++ : species was extremely abundant but not counted
    NS : not significantly different
 

	Inside	Tires				Outside	Tires				Inside	Outside	paired
Organism	1	2	3	4	5	1	2	3	4	5	Average	Average	t-test
Ph. Porifera (sponges)
Halichondria bowerbanki	+	+	+	+	+	+	+	+	+	+	+	+
Scypha	1	4	2	3	0	0	+	0	0	0
Ph. Cnidaria (hydrozoans, anemones)
Garveia annulata							++			+
Plumularia setacea	+					++	++	++	+	+		+
Other Hydroids		+	+		+		+				+
Metridium senile	13	28	55	65	28	5	2	4	15	20	37.8	9.2	p < 0.05
Urticina spp.	0	1	4	0	0	4	3	1	2	2	1	2.4	NS
Cl. Polychaeta (segmented worms)
Serpulidae	5	8	7	16	8	2	0	0	1	2	8.8	1	p < 0.05
Sabellidae	0	4	13	20	12	7	6	7	2	20	9.8	8.4	NS
Spirorbidae	+	+	+	+	+	+					+
Ph. Mollusca
Tonicella lineata (chiton)	1	1	0	0	0	1	1	2	1	0	0.4	1	NS
Collisella pelta (limpet)	5	0	0	1	0	21	12	7	1	3	1.2	8.8	p < 0.1
Mytilus edulis (mussel)	1	0	0	0	0	34	10	7	16	10	0.2	15.4	p < 0.05
Ph. Bryozoa
Bugula californica	+	+	+	+							+
Bugula pacifica	+	+		+							+
Dendrobeania lichenoides	++	+	+	+	++	+	+	++	+	+	+	+
Membranipora membranacea	++	+	+	+	+	+			++		+
Scrupucellaria	+					+		+		+		+
Encrusting bryozoans	+	+	+	+	+						+
Cl. Cirripedia (barnacles)
Balanus nubilis	9	14	13	4	27	45	34	56	17	18	13.4	34	p < 0.1
B. glandula + B. crenatus	33	75	74	105	11	61	86	79	22	91	59.6	67.8	NS
Cl. Ascidiacea (tunicates/sea squirts)
Chelyosoma productum	23	47	35	52	20	2	6	9	7	8	35.4	6.4	p < 0.01
Boltenia villosa	1	2	0	8	0	0	6	3	1	2	2.2	2.4	NS
Distaplia occidentalis	86	113	95	150	138	41	42	80	15	61	116.4	47.8	p < 0.05
Aplidium spp.	0	0	5	2	2	1	2	8	2	2	1.8	3	NS
Corella willmeriana	0	1	5	0	2	0	0	0	0	0	1.6	0	NS
Algae
Mastocarpus papillatus	+	+	+			+				+	+
Ulva fenestrata	+	+	+		+	+	+		+		+	+
Laminaria saccharina	+	+	+	+	+						+
Callophyllis edentata	++	+	+	+		+	+		+		+	+
Desmarestia viridis	+	+	+	+		+				+	+
Membranoptera platyphylla		+	+	+	+	+	+	++	++	++	+	+
Alaria marginata					+	+	++	+	+	++		+
Porphyra sp.		+	+	+	+	+	+				+
Iridaea cordata	+			+				+