Vis 15 – 20’, 59 – 61 degrees. Depth 51 – 55’ at the sand, <35’ at the top of the pipe.

On the first day, Phil and I tried a shallower spot on the pipe than usual, hoping to find different subjects. Since it was closer to shore, surge was pretty strong along the pipe making for some fly-by shooting. Feather duster worms and large anemones were more plentiful than we find at deeper areas of the pipe. We were surprised by the absence of gray moon sponge, which is home to many species of nudibranchs, hermit crabs and amphipods.

The second day, we anchored at the deep end (~55 fsw) of the pipe where there has always been a cornucopia of nudibranchs and other inverts dotting massive gray moon sponge. Not anymore. It appears the grand old sponges were ripped from the pipe, perhaps during last year's ferocious winter storms. In the sponge's place and dominating the 12-foot diameter pipe are endless fields of Mytilus californianus, the California mussel.

I swam toward shore, to the third stanchion from the end, where I've previously found red rock (cleaner) shrimp and lobster. There's a small gap between the third stanchion and the pipe, just large enough for something to hide. But I forgot all about the shrimp when I was astounded by the sight of FOUR two-spot octopus lining the opening! Have octopus moved into this territory due to the bounty of mussels?

Buoy marking the end of the Hyperion 1-mile elevated pipe.

Polymorph featherduster worm, Eudistylia polymorpha

Sunburst anemone, Anthopleura sola

Moonglow anemone, Anthopleura artemisia

Moonglow anemone, Anthopleura artemisia

Aggregating anemone, Anthopleura elegantissima

Phil pointed out the always-fun-to-shoot mussel blenny, Hypsoblennius jenkinsi

Massive gray moon sponges have been reduced to these small clumps. Spheciospongia confoederata.

Two-spot octopus (no. 1), Octopus bimaculatus

Two-spot octopus (no. 1), Octopus bimaculatus

Two-spot octopus (no. 2), Octopus bimaculatus

Two-spot octopus (no. 3), Octopus bimaculatus

Two-spot octopus (no. 4), Octopus bimaculatus

Barred sand bass, Paralabrax nebulifer

C-O sole, Pleuronichthys coenosus

Chestnut cowry, Neobernaya spadicea, on gray moon sponge.

Ochre star, Pisaster ochraceus

Massive ochre star

San Diego dorid, Diaulula sandiegensis

Tiny Aegires albopunctatus

Doriopsilla albopunctata mating

Nudibranch eggs

Doriopsilla gemela

Corynactis, bivalves and worms compete for space on the tightly-packed pipe.

• Re: Two days on the Hyperion Treatment Plant 1-mile elevated outfall pipe, El Segundo, CA Merry 12:57:31 11/26/23 (0)