My research is focused on understanding the resilience of kelp bed ecosystems and possible mechanisms that can trigger phase shifts to alternative states. My thesis examines deep-living populations of green sea urchins along the Atlantic coast of Nova Scotia and their connectivity to shallow kelp bed ecosystems. I am particularly interested in the importance of drift kelp export from shallow kelp beds to adjacent food-limited areas and the impact of this subsidy on the spatial distribution and reproductive condition of deep-living sea urchins.
More recently, I have been documenting long-term changes in kelp biomass and cover along the coast of Nova Scotia, and examining the hypothesis that ocean warming may be shifting the competitive interaction between kelp and turf-forming algae in favour of turfs.
I have shown that substantial drift kelp deposition occurs off the coast of Nova Scotia and that sea urchins in deep depositional areas can be highly reproductive. These deep populations exist in a thermal refuge from a disease that decimates warmer shallow populations and may play an important ecological role in restoring shallow populations after mass mortality. Deep sea urchin populations may also play a key role in destructive grazing events in which sea urchins emerge from deep regions and graze kelp beds to unproductive sea urchin barrens.
Filbee-Dexter K, RE Scheibling (2016). Spatial patterns and predictors of drift algal subsidy
in deep subtidal environments. Estuar Coast
Filbee-Dexter K, CJ Feehan, RE Scheibling (2016) Large-scale degradation of a kelp
ecosystem in an ocean warming hotspot. Mar Ecol Prog Ser 543: 141–152.
Filbee-Dexter K, Scheibling RE (2014) Detrital kelp subsidy supports high reproductive condition of deep-living sea urchins in a sedimentary basin. Aquat Biol 23, 71-86. pdf
Filbee-Dexter K, Scheibling RE (2014) Sea urchin barrens as alternative stable states of collapsed kelp ecosystems. Mar Ecol Prog Ser, 495, 1-25. pdf
Francis FTY, Filbee-Dexter K, Scheibling RE (2014) Stalked tunicates Boltenia ovifera form biogenic habitat in the rocky subtidal zone of Nova Scotia. Mar Biol 161 (6), 1375-1383
Filbee-Dexter K, Scheibling RE (2013) Hurricane-mediated defoliation of kelp beds and pulsed delivery of kelp detritus to offshore sedimentary habitats. Mar Ecol Prog Ser, 455, 51-64. pdf