Examining the Effects of Food Supply on Eastern Oyster (Crassostrea virginica) Larval Performance and Settlement Potential in Delaware Bay and Mississippi Sound

<p>Oyster population maintenance and growth require sufficient larval stocks capable of timely development, growth, and successful metamorphosis, whereby larval performance and settlement potential determines the capacity for a larval cohort to effectively establish into an existing population. Exogenous factors influencing larval performance include temperature, salinity, and particularly food supply. Regarding food, a sufficiently abundant and nutritionally balanced diet composed of protein, lipids, and carbohydrates is critical for successful metamorphosis. The influence of exogenous factors on <em>Crassostrea virginica</em> settlement potential were examined in Delaware Bay and Mississippi Sound by incorporating <em>in situ </em>environmental conditions and food supply metrics into a well-established biochemically-based larval performance model. Additionally, physiological variation in initial egg size, lipid content, and assimilation efficiency was modeled to reflect potential within-cohort phenotypic variability. Extended periods of suppressed salinity routinely impeded larval survival, but under adequate environmental conditions, food quality was the primary control on larval success. Reproductive seasons with favorable exogenous conditions prolonged settlement windows whereas strenuous conditions constrained settlement windows. Evaluating simulated settlement windows against concurrent recruitment observations validated the predictive power of the model and emphasized the importance of food quality on larval performance. To further characterize food assemblages available to oyster larvae in Mississippi Sound, linkages between inherent optical properties to environmental conditions and biochemical food metrics were investigated. Phytoplankton and colored detritus distributions were inferred via measured absorption coefficients but exhibited weak correspondence to biochemical metrics. Optical analyses demonstrated that biochemical food analyses remain superior food supply indicators over chlorophyll and particulate matter measurements.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Masters Thesis

Year dc:date.available

2024

Author dc:creator

• Klein, James C.

Contributors dc:contributor

• Dr. Eric N. Powell
• Dr. Xiaodong Zhang
• Dr. Chet F. Rakocinski

• Crassostrea virginica
• larvae
• biochemical
• food supply
• absorption
• phytoplankton
• Marine Biology

Repository record dc:identifier

https://aquila.usm.edu/masters_theses/1037

OAI identifier oai:identifier

oai:aquila.usm.edu:masters_theses-2102