Meeting Abstract
Bull kelp, Nereocystis luetkeana , is the dominant kelp forest species in the Salish Sea and plays an important role in the marine coastal ecosystem. The biogenic structure formed by N. luetkeana provides habitat for marine mammals, crustaceans, echinoderms, mollusks, and fish and increases the productivity of the ecosystem. Throughout its lifecycle N. luetkeana faces a variety of biotic stressors that impact its distribution and abundance. Key biotic stressors are competition, sori availability, and predation. The relative impacts of availability of sori and competition on the abundance of N. luetkeana were explored through a subtidal experiment. Data suggests that competition between macroalge for light is the limiting factor in settlement and growth. Once the macroalga survives settlement it still faces other stressors, such as predation. Feeding trials with two species of kelp crabs, P. gracilis and P. producta, tested feeding electivity on N. luetkeana. Results suggest a preference in both species for juvenile stipe in comparison to juvenile blade and sori over non reproductive blade. P. producta also elected to eat mature blade over mature stipe. Identification of challenges faced by N. luetkeana has the potential to allow for more informed preservation and restoration.
