APPENDIX E 



OBSERVATIONS ALONG NATURAL BOTTOM TRANSECT 



The following is a discussion of substrate and biotic composition 

 of the first segment of the transect (13.7- to 6.1-meter depth). 



Over the depth range 13.7 to 11.3 meters, the substrate is silt 

 with some shell fragments. The sediment is very soft and similar to 

 that existing at the base of the east side of the island. The domi- 

 nant biota are sea pens (Stylatula elongata) , bat stars (Patiria 

 miniata) , whelks (Kelletia kelletii) , and cerianthid anemones. On a 

 few isolated rocks (maximum vertical relief 0.25 meter) stony corals 

 {Astrangia lajollaensis) were present and the tectibranch, Navanax 

 inermis , was observed. 



At about 10.7 meters the substrate is more sandy with many shell 

 fragments. Isolated smooth boulders (1- to 2-meter diameter) are 

 present with the evidence that they are intermittently covered with 

 sand (no epiphytic algae present). Diopatra spp. are common to abun- 

 dant in patches of up to about 100 individuals. Kelletia, Patiria, 

 and Strongylocentrotus franciscanus are present. Vertical pipes 

 (about 1 meter high) were observed with cf. Metridium sp. attached. 

 Diaulula sandiegensis, Corynactis California, Cancer sp., cf. 

 Stylatula, and cerianthid anemones were present. Also at this depth, 

 gorgonians (Muricea spp. and Lophogorgia chilensis) appear on iso- 

 lated rocks, with Muricea common to locally abundant. 



From 10.7 to 9.1 meters, smooth boulders, as described above, 

 dominate the substrate. However, these boulders are more heavily 

 encrusted with Astrangia, Veleroa, and Lithothamnium complex. Around 

 the rock bases, where some sand is present, Diopatra ornata occur. 

 The midshipman (Porichthys spp.), juvenile olive rockfish (Sebastes 

 serranoides) and sanddabs (Citharichthys sp. ) are also present. 

 Lithothamnium coverage ranges up to 15 to 20 percent of exposed rock 

 areas. Also present on vertical pipes and rocks are sponges (Leucetta 

 losangelensis) , Metridium, and Strongylocentrotus franciscanus. 

 Strongylocentrotus purpuratus was also observed along these depths, 

 but this species was not abundant. Cypraea spadicea, Tethya aurantia, 

 Pisaster brevispinus, P. giganteus , and Dermasterias imbricata were 

 also present to common on the solid substrate. 



From 7.6 to' 6.1 meters the substrate changes from smooth boulders 

 to solid shale bedrock with isolated boulders and sand patches. 

 Pholad bivalves, starfish, and urchins dominate the macrobiota. Some 

 red alga (Veleroa complex and Lithothamnium) are present; also juve- 

 nile red algae was observed attached to the rock. 



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