Graduation Year

2020

Document Type

Thesis

Degree

M.S.

Degree Name

Master of Science (M.S.)

Degree Granting Department

Biology (Integrative Biology)

Major Professor

Melanie Riedinger-Whitmore, Ph.D.

Co-Major Professor

Paul Carlson, Ph.D.

Committee Member

Alison Gainsbury, Ph.D.

Keywords

flower, hydrophily, life history, pollen, seagrass, turtlegrass

Abstract

Successful sexual reproduction and recolonization are critical in maintaining genetic diversity within seagrass meadows. Thalassia testudinum flower, fruit and seedling production were assessed visually at 10 sites within Tampa Bay, Florida approximately every 4 weeks from May to July 2017 to determine if there is spatial and temporal variation in sexual reproductive effort and if location within a meadow effects sexual reproductive effort. Results from this study reveal strong temporal variability throughout the reproductive season. The month of May was observed as peak Thalassia testudinum anthesis and June was peak fruiting in Tampa Bay during 2017. Flower and fruit density ranged from 0.19 ±0.75 to 0.54 ± 1.38 per 0.25m2 and 0 to 0.59±1.550 per 0.25m2, respectively. Highest and lowest flower densities were observed at CK03 and CB02, respectively and highest and lowest fruit densities were observed at CK01 and both CB02 and WD07, respectively. Mean reproductive effort ranged from 0.51±1.82 0.25m2 to 1.92±4.86 0.25m2 with the lowest at JB04 and the highest at EK01. Additionally, results suggest site location, water quality, seagrass density, and localized reproductive variability affect sexual reproductive effort and success. Only 7 seedlings were observed during the survey suggesting that asexual reproduction is the dominant form of meadow growth and expansion in Tampa Bay. These results also suggest that while acreage has reached target goals set forth by the Tampa Bay Estuary Program in the early 1990’s, these meadows have not fully recovered and may be susceptible to natural and anthropogenic stressors.

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