Annie Nyffeler, Nebraska Wesleyan University

Class Year:

2015

Mentor:

Thomas Miller, Ph.D.

Abstract:

A rise in atmospheric CO₂ induces a greenhouse effect that also causes ocean temperatures and CO₂ levels to rise. These environmental changes may represent an additional energetic cost for blue crabs because they rely on the concentration of CO₂ in the water to deposit calcium carbonate in their shells. We conducted a respiration experiment to measure the effect of climate change on crab metabolism. Crabs were collected from the Chesapeake Bay and exposed to different heated and acidified conditions. After crabs had been exposed to the environmental conditions in the chambers for two molts, they were placed in respiration chambers to measure rates of oxygen consumption. Results indicated different trends in respiration rates between the treatments, although the patterns were not statistically significant. Crabs exposed to higher temperatures showed elevated respiration rates, while crabs exposed to high CO₂ demonstrated decreased respiration rates. The two factors of climate change (high temperature and high CO₂) did not demonstrate the highest respiration rate, but rather the crabs exposed to high temperatures and ambient CO₂ showed the highest mean respiration rate. These data suggest that crab metabolism may not change as much as expected due to climate changes. 

Location:

Chesapeake Biological Laboratory