Date of Award

5-2022

Document Type

Thesis

Degree Name

Master of Science (MS)

College/School

College of Science and Mathematics

Department/Program

Biology

Thesis Sponsor/Dissertation Chair/Project Chair

Colette J. Feehan

Committee Member

Matt Schuler

Committee Member

Sean Grace

Abstract

Increasingly severe ocean warming and marine heatwave events are driving declines in habitat-forming kelps worldwide. Direct mortality from extreme temperatures, coupled with destabilization of kelp forest communities, commonly trigger ecological community shifts from dominant kelp forests to an algal turf dominated state. Opportunistic algal turf species are more resilient to warming and lack the fundamental structure of kelp forests, and thus reduce ecosystem services and biodiversity. Once in place, algal turf communities contain ecological feedback mechanisms, diminishing kelp recruitment, and potential recovery. The various feedback mechanisms and ecological thresholds that maintain or drive community shifts between kelp forest and algal turf are not well understood. Likewise, the effects of sea urchin herbivory within these degraded algal turf communities remain poorly described, but likely have profound effects on the maintenance or drivers between these ecosystem states. Here, I present research into the grazing preferences of the thermophilic sea urchin Arbacia punctulata within a degraded Saccharina latissima kelp forest ecosystem dominated by algal turf in coastal Narragansett Bay, Rhode Island, USA. I find that A. punctulata grazes more heavily on algal turf assemblages than S. latissima with and without diet choice. My results corroborate field observations that A. punctulata graze on algal turf in the field and indicate the value of investigating A. punctulata grazing behavior further to understand their potential effects or utilization in kelp forest restoration strategies.

Comments

Marine Biology and Coastal Sciences Program

File Format

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