Under conditions of fixed N-limitation, as with most oligotrophic systems, the process of biological N₂ fixation (diazotrophy) is favored, provided the necessary trace elements and vitamins are sufficient. Despite the well understood contributions of N₂
fixation in oligotrophic regions, the nutritional and ecological controls of marine diazotrophs have not been...
The relative lability, elemental stoichiometry, and remineralization rates of various particulate organic matter (POM) substrates by natural heterotrophic marine microorganisms was investigated. POM was harvested from laboratory cultures of a marine diazotroph (Trichodesmium IMS101), a cosmopolitan diatom (Thalassiosira weissflogii), a common marine cyanobacteria (Prochlorococcus MED4), and from surface waters off...
Significant seabird mortality on the Oregon (OR) and Washington (WA) coast in 2009 has been attributed
to a massive bloom of the dinoflagellate Akashiwo sanguinea (K. Hirasaka) G. Hansen & Ø. Moestrup.
Initial, albeit limited, observations suggested this bloom began in WA and reached OR waters through
southward transport. Here,...
Full Text:
. White a,*, KatieS. Watkins-Brandt a, S. Morgaine McKibben a,
A. Michelle Wood b, Matthew Hunter c, Zach
Significant seabird mortality on the Oregon (OR) and Washington (WA) coast in 2009 has been attributed
to a massive bloom of the dinoflagellate Akashiwo sanguinea (K. Hirasaka) G. Hansen & Ø. Moestrup.
Initial, albeit limited, observations suggested this bloom began in WA and reached OR waters through
southward transport. Here,...
Full Text:
California
current system in 2009
Angelicque E. White a,*, KatieS. Watkins-Brandt a, S. Morgaine McKibben a
We present a spatially extensive record of dinitrogen (N₂) fixation rates and distributions
of N₂ fixing microorganisms along with the results of exogenous phosphorus (P) addition experiments
conducted during a series of cruises in the North Pacific Subtropical Gyre (NPSG). We measured the
N₂ and carbon (C) fixation rates of...
Preservation of rare plant species often requires establishment of new populations. Survivorship surveys are the most common method of post-introduction monitoring. However, they provide an incomplete picture of establishment success. This study is an attempt to develop a model for determining establishment success by determining the factors affecting recruitment in...
In contrast with other Odocoileus species, Columbian black-tailed deer (Odocoileus hemionus columbianus) population dynamics are not well understood throughout the species’ range. Concerns over apparent long-term population declines have prompted efforts to fill basic knowledge gaps including estimates of vital rates (fecundity, recruitment and survival) and cause-specific mortality. The Oregon...
The accumulation of domoic acid (DA) and saxitoxins (STX), phycotoxins produced by some species of Pseudo-nitzschia and Alexandrium, respectively, in coastal food webs are a focus of research on the West Coast of the United States due to the deleterious effects they have on coastal ecosystems and economies. Results are...
Significant seabird mortality on the Oregon (OR) and Washington (WA) coast in 2009 has been attributed to a massive bloom of the dinoflagellate Akashiwo sanguinea (K. Hirasaka) G. Hansen & Ø. Moestrup. Initial, albeit limited, observations suggested this bloom began in WA and reached OR waters through southward transport. Here,...
It is critical for wildlife managers to understand the population dynamics of a harvested species, particularly for ungulates, which are a valuable wildlife resource. Due to concerns that mule deer (Odocoileus hemionus) populations in Oregon were declining, more comprehensive data on population vital rates and the factors potentially affecting them...