Date of Award

Spring 2026

Degree Type

Thesis

Department

Biological Sciences

Director of Thesis

Dr. Jerry Hilbish

Second Reader

Dr. Joshua Stone

Abstract

This paper explores how the recovery of populations of Semibalanus balanoides is affected by climate variation. In intertidal marine ecosystems, larval recruitment is important in shaping all ecological processes. S. balanoides is a cold-water barnacle species that is competitively dominant over Chthamalus montagui and C. stellatus, two warm-water species. This competitive interaction is well studied, though it is not understood how that competition influences the recovery of S. balanoides after a disturbance nor how this process varies over a temperature gradient. 19 sites were studied across the United Kingdom, spanning from northern Scotland to southwestern England. At each site, a disturbance was simulated by scraping rock surfaces in the intertidal zone to remove all organisms. Recovery of the scraped populations was measured by observing the percent cover and opercular length of S. balanoides in comparison to the control population at each site. It was determined that at sites located in Scotland, the northernmost and coolest region, recovery was complete in 3 years. Little interaction between S. balanoides and Chthamalus occurred in this region. At sites located in Wales, recovery did reach completion at each site, though at variable rates. This region experiences both cold and warm temperatures. There was also some interaction observed between S. balanoides and Chthamalus. Finally, at sites located in southwest England, recovery never occurred. Instead, a localized extinction of S. balanoides was observed while a steady increase of Chthamalus occurred simultaneously. This was the warmest region studied. These results demonstrate a strong influence of temperature on competitive interactions and population recovery. As temperatures around the globe rise, cold-water species like S. balanoides may no longer be the competitively dominant species, changing these existing community structures.

First Page

1

Last Page

47

Rights

© 2026, Lauren Tibbits

Download

Share

COinS