Biological Dredge

Station: BioDredge / Rock Pile
Date: 10/21/2016, 9:12 am
Conditions: 69° F, sunny, no clouds, winds N 0 mph
Latitude: 33° 40' 5'' N to 33° 40' 32'' N
Longitude: 118° 13' 46'' W to 118° 13' 33'' W

Sediment Desc: Brown pebble to boulder subangular clasts of siltstone and sandstone
Flora & Fauna: Kellet's whelk, brittle star, kelp-encrusting bryozoan, painted = white) urchin, Spiney Sand Star, Cone Snail, red encrusting algae, turkish towel algae, red algae, hermit crab, clamshell with eggs inside and barnacles outside..

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.

Below are some pictures of the organisms we collected during this biodredge. All creatures were returned to the ocean.

  • Holdfast
  • Holdfast
  • Holdfast
  • Bryozoans on kelp
  • Marine organisms take advantage of the bounty in the ocean.  In this case, a barnacle has attached itself to a clam shell.
  • Hatched eggs inside of a clam shell.
  • Isopod
  • Kellet's Whelk
  • Kellet's Whelk
  • Kellet's Whelks (top)
  • Kellet's Whelks (bottom)
  • Wentletrap
  • Wentletrap