Date of Award

Spring 2015

Document Type

Undergraduate Honors Thesis

Degree Name

Bachelor of Arts in Biology

Department

Biology

Advisor

Sue Lowery

Abstract

Internal waves have been proven to transport invertebrate larvae onshore, but there has been little indication on whether internal waves transport fish eggs. Fish eggs are typically buoyant and are often found in neustonic samples, and internal waves often cause fronts that transport oils and other light particles. This research aims to determine whether there are patterns to the distribution of fish eggs. One possibility is that offshore fish eggs can be transported onshore, to nearshore nursery habitats. Before 2003, when genetic barcoding was proposed as an identification mechanism, fish eggs could only be identified visually, using color, size, and shape. However, this method can be unreliable, so this research utilizes the COI barcoding gene to identify fish eggs to a species in samples taken in the South La Jolla State Marine Preserve, an area known to experience internal waves. Samples were taken within internal wave events and also at times without internal waves for control samples. Overall, 14 species of fish were found throughout the samples via DNA barcoding, 13 in event samples, and 7 in control samples. One sample was unable to be identified to a species, due to a higher level of species divergence from the most closely related sequenced specimen. No statistically significant differences were seen in abundance or distribution, although weak trends were seen that more fish eggs were found during event samples than in controls, and that more species were found in event samples. After calculation of diversity indices, only Simpson’s evenness showed significant differences, with event samples being more evenly distributed than control samples. Overall, fish eggs were found during internal wave fronts, indicating that they can be transported. However, insights as to how or why these eggs are transported are unclear, including whether or not the eggs are simply carried along in the fronts by accident.

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