Biological Dredge

Station: Rock Pile
Date: 3/16/2019, 9:20 AM
Conditions: 77° F, cloudy, winds W 7 mph
Start: 33° 40' 24" N, 118° 13' 27" W
End: 33° 40' 34" N, 118° 13' 20" W

Sediment Desc: Gravel to boulder sized rocks (siltstones)

Kelp does not put down roots in the sediments on the seafloor. Instead, it anchors itself onto rocks. Many organisms make these rocks their own. The area on the San Pedro shelf called the "Rock Pile" is where the coastline used to be 10,000 years ago. As the planet warmed and the ice sheets melted, sealevels rose, covering this rocky coastline with seawater.

  • Holdfast
  • Holdfast
  • Holdfast
  • A stalked tunicate attached to some feather hydroids.
  • Some tiny strawberry anenomes.
  • More tiny strawberry anenomes.
  • Hermit Crab (bottom)
  • The hermit crab took up residence inside a Kelllet's Whelk shell. On top of hte shell are some red encrusting algae and a baracle, which helps to camouflage the crab.
  • Sand Dollar
  • A brittle star
  • Heart Urchin
  • Heart Urchin
  • Several white urchins
  • A collection of varies echinoids
  • Brown Cowrie
  • Frog Snail (top)
  • Frog Snail (bottom)
  • Kellet's Whelk (top)
  • Kellet's Whelk (bottom)
  • California Bubble Snail