Date of Award


Document Type

Honors Thesis (Open Access)


Colby College. Environmental Studies Program


Alison Barner

Second Advisor

Denise Bruesewitz

Third Advisor

Peter Countway


Stressors associated with climate change including thermal stress and ocean acidification inhibit the growth and reproduction of many species, including the ecologically and economically important blue mussel species in the Gulf of Maine (GOM). Established scaling relationships between mussel size, abundance, and water filtration suggests that the decline of mussels will stunt GOM water filtration. This change in the rate of water filtration could have large effects on the abundance of phytoplankton, abundance of invertebrate larvae, abundance of nutrients and organic material, food web stability, and biodiversity. Overall, this thesis explores the effect of blue mussel (Mytilus edulis) extinction on the rate of water filtration, as well as the effect of secondary extinctions of rockweed (Fucus distichus) and acorn barnacles (Semibalanus balanoides) on water filtration by mussels. Using allometric relationships between size and filtration and combining these with data from the Barner Lab, an ongoing field extinction experiment that tracks the long-term shifts in species abundance and diversity after the experimental extinction of foundation species, I examined how species extinctions will affect mussel abundance and water filtration rates. Overall, the removal of both S. balanoides and Fucus distichus correlated with a dramatic decline in the total water filtration rate by M. edulis. Therefore, the projection of water filtration decline by mussels will likely be amplified by simultaneous species decline.


Blue Mussel, Gulf of Maine, Extinction, Water Filtration, Ecosystem Service, Mytilus edulis