Effects of Wave Action on the Structure of Fish Assemblages Across an Exposure Gradient

<p>Disturbance affects the function and diversity of ecosystems. Increased wave exposure to salt marsh can disturb sediments and cause a loss of habitat. The purpose of this study was to explore the effects of increased wave exposure on diversity, abundance, and functional ecology of estuarine fishes. If increased wave exposure is acting as a disturbance to these habitats, ecological theory (Intermediate Disturbance Hypothesis) predicts that diversity will peak at intermediate frequencies and intensities of disturbance. Fish were sampled from 10 sites monthly for 6 years. The sites were assigned to different exposure categories (Open, Intermediate, and Sheltered) using an exposure assessment method. My results did not support the Intermediate Disturbance Hypothesis. Abundance was highest at the most open sites. No significance functionality difference was found between groups. I used geometric morphometrics to determine if the increased exposure had an effect on the body shape of 4 abundant species. In freshwater studies, patterns of flow have plastic and evolutionary effects on body shape in fishes with individuals caught in faster flow having more streamline bodies and larger fin area. I was curious if the same trends would be observed in estuaries. The shape analysis yielded significant differences between exposure groups; however, not in the way expected when compared to the results from other studies. In conclusion, diversity, abundance, and shape differences were found when comparing exposure groups. However, increased wave action alone is not the driving factor; therefore I deduce the presences of other stressors and factors in this habitat affecting the dispersal and shape of individuals.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Masters Thesis

Discipline thesis:degree_discipline

Biological Sciences

Year dc:date.available

2017

Author dc:creator

• Liddon, Lauren

Contributors dc:contributor

• Jake Schaefer
• Mike Davis
• Paul Mickle

• Wave action
• disturbance
• exposure
• fish
• shape
• diversity
• Biodiversity
• Biology
• Zoology

Repository record dc:identifier

https://aquila.usm.edu/masters_theses/302

OAI identifier oai:identifier

oai:aquila.usm.edu:masters_theses-1325