Date of Award


Document Type

Campus Access Dissertation


Earth and Ocean Sciences



First Advisor

Benitez-Nelson, Claudia


In the marine environment, the bioavailability of phosphorus (P) can impact ocean fertility as well as the structure and distribution of phytoplankton communities. Particulate P is of special interest because it is the major mechanism for the transport of P to deep waters and is a source of P to nutrient-depleted surface waters through upwelling and mixing. Changes in nutrient conditions (magnitude and nutrient ratios) can increase the potential for eutrophication and in some cases, facilitate the growth of harmful algal blooms (HABs). One such HAB is the diatom genus Pseudo-nitzschia, which can produce the neurotoxin domoic acid (DA) and has been responsible for numerous marine mammal and bird mortalities on the West Coast of the U.S. The goal of this dissertation is to examine particulate P cycling, Pseudo-nitzschia blooms, and DA export using a 13-year record (August 1993 - August 2006) of sinking particles continuously collected at ~500 m depth by a sediment trap deployed in Santa Barbara Basin (SBB) off the coast of southern California. Sampling included analysis of overlying solutions within sediment trap cups and therefore a detailed examination of possible diagenetic artifacts associated with prolonged sediment trap collection periods.

SantaBarbaraBasinSedimentTrapData.xls (582 kB)
Phosphorus and Domoic Acid Data