Thesis Defense by Natalie Yingling – July 20th, 2018

ATP as a Quantitative Proxy for Living Microbial Biomass: Cellular ATP Content Under Stress

A Thesis Defense by Natalie Yingling

Biological Oceanography Lab

Friday, July 20th, 2018 at 4pm

MLML Seminar Room

Natalie Yingling is a Master’s student under the guidance of Dr. Nick Welschmeyer in the Biological Oceanography lab. She started at MLML in Fall 2015 after earning her B.S. degree in Marine Science with a concentration in biological oceanography from North Carolina State University in Spring 2015. During her time at MLML she has participated in various research cruises, worked as a research assistant for Dr. Welschmeyer as part of the ballast water testing team that works in conjunction with Cal Maritime, was vice president of MLML in 2016 and has participated every year in MLML’s annual open house. In Fall 2018 she will be starting a Ph.D. program at Florida State University in the department of Earth, Ocean and Atmospheric Science. Her thesis focuses on implementing measurements of adenosine triphosphate as a proxy of microbial biomass in stressed and dying cells.

Thesis Defense by C. Ryan Manzer – December 12th, 2017

Physical Factors Influencing Phytoplankton Abundance in Southern Monterey Bay

A Thesis Defense by C. Ryan Manzer

Physical Oceanography Lab

Tuesday, December 12th, 2017 at 4pm

MLML Seminar Room

Thesis Abstract:

As the base of almost all marine food webs, phytoplankton play a dominant role in determining the productivity of marine ecosystems. Recent studies have highlighted the dynamic variability of phytoplankton abundance in nearshore ecosystems over synoptic time scales. The inability of satellite ocean color monitoring to resolve chlorophyll values at a resolution less than 1 km and a reliable temporal resolution of ~8 days means this data cannot adequately capture the impact of nearshore dynamics on chlorophyll abundance and distribution. Therefore, a greater understanding of the physical mechanisms that contribute to this variability is required to assess impacts of current as well as future weather patterns on these ecosystems. In this study, chlorophyll fluorescence data from a nearshore location in the south Monterey Bay is used to identify the timing and duration of increases in phytoplankton concentrations.  Physical parameters, including wind stress and water temperature were analyzed to determine whether upwelling and/or upwelling relaxation events correlate with observed blooms. A significant negative correlation between water temperature and chlorophyll was found for the two summer seasons studied (2012, 2013) which suggess that increases in chlorophyll concentrations are more likely due to advection than biological reproduction. The results of this study suggest that phytoplankton are advected into the southern Monterey Bay during wind relaxation events of great enough magnitude to disrupt dominant circulation patterns. These impacts are site specific and demonstrate the degree to which the ecological subsidies can vary over small spatial ranges at synoptic scales.