Date of Award

Winter 2024

Project Type

Thesis

Program or Major

Biological Sciences

Degree Name

Master of Science

First Advisor

Brittany Jellison

Second Advisor

Leslie Curren

Third Advisor

Nathan Furey

Abstract

Increased absorption of anthropogenic carbon dioxide (CO2) into the world’s oceans has resulted in ocean acidification (OA). Acidification induces physiological and behavioral responses from marine invertebrates that vary by taxa. Resilience to OA has been noted in crustaceans, though negative impacts are still reported. It has been shown that the American lobster (Homarus americanus) can be physiologically impacted by acidified conditions. We explored the effects of acidification on the hemolymph chemistry and the foraging behavior of juvenile American lobsters (carapace length, CL, 29 - 52 mm, 42 +/- 1.3 mm). We exposed 28 juvenile lobsters to individual pH values ranging from 7.3 to 7.8 for twelve days to observe potential impacts of acidification on foraging behavior. After exposure, we assessed hemolymph L-lactate concentration (as an indicator of stress), time to locate the blue mussel prey, number of foraging trips taken, and time taken to successfully feed on blue mussels. As pH decreased, lobsters successfully fed two-times quicker, maintained normal times to locate prey, and took fewer trips in reduced pH conditions when prey was absent. We found that across pH values, lobsters responded to prey cues similarly, suggesting that olfaction was likely not impaired. Counter to our predictions, these results indicate that exposure to acidified conditions may increase the foraging activity of juvenile H. americanus.

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