de Angelis, M. A. Humboldt State University, mad1@axe.humboldt.edu
Davis, B.
Downey, G.
Fowler, M.
Grimes, S.
Logan, M.
Puleo, J.
Schneider, M.

 
DISTRIBUTION AND POTENTIAL ECOLOGICAL SIGNIFICANCE OF EPIBENTHIC WOODY DEBRIS ON A NORTHERN CALIFORNIA CONTINENTAL SHELF
 
Results of an investigation into the ecological roles and distribution of epibenthic woody debris (EWD) on the Eel River Shelf off northern California will be presented. Bottom trawls and camera surveys were carried out at sites chosen to test the effect of proximity to the riverine source of woody debris, water depth and shelf slope on abundance and use of EWD by fauna on the Eel River Shelf. Large amounts of wood are introduced to the shelf during 2 or 3 annual flood events during winter and early spring. Stations closest to the Eel River were characterized by small amounts of large EWD while offshore stations had large volumes of much smaller EWD. Seasonally, from spring to fall, wood was found to migrate offshore along the bottom in a northwesterly direction. Bottom currents and wood surface/volume ratios appeared to be the primary factors responsible for EWD movement. Camera surveys indicate that small piles of large wood pieces may serve as sites of shelter for marine organisms on a seasonal basis, while larger volumes of smaller pieces of wood are less important. Large amounts of wood found to be permanently deposited in bathymetric depressions and slumps may be more important ecological niches.
 
Day: Thursday, Feb. 4
Time:
Location: Sweeney Center
 
Code: CS63TH0177S