Researcher ORCID Identifier


Graduation Year


Document Type

Open Access Senior Thesis

Degree Name

Bachelor of Arts


Environmental Analysis

Reader 1

Branwen Williams

Reader 2

Diane Thomson

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© 2022 Teagan McMahon


Crustose coralline algae (CCA) are important organisms that create benthic habitat in the photic zone of oceans worldwide. CCAs mechanisms of photosynthesis and calcification may, in some cases, make them vulnerable to climate change and ocean acidification. Therefore, CCA are important not only for their ecological role within ecosystems but also for their ability to indicate the effects that ocean acidification and climate change may have on other marine calcifying organisms. Some species of CCA are known to be useful recorders of paleo oceanic conditions. These climate archives and reconstructions of past environmental conditions are important for understanding past changes in oceanic conditions. This study was done using the coralline red alga Clathromorphum compactum which is shown to be suitable as a climate archive in high latitude marine environments. This study seeks to understand the effect of unideal environmental conditions on C. compactum. Wild collected C. compactum specimens were grown in varying temperature (3, 6 or 9ºC) and pH (7.4, 7.6, 7.8 or 8) experimental conditions and then analyzed for growth (linear extension) and 18O (isotope ratio mass spectrometry). The analysis showed that growth was not influenced by temperature or pH. This suggests resiliency of C. compactum growth under unideal environmental conditions. This study confirmed the relationship between skeletal calcite 18O and temperature and quantified this relationship in a controlled experiment for the first time in this species.

Available for download on Thursday, May 15, 2025