Project: Effects of ocean climate change on recruitment of kelp populations

NSF Award Abstract:
Kelps inhabit a narrow band of the Earth's ocean margins, yet they sustain some of the most diverse and productive ecosystems on the planet. Despite over 50 years of intensive field and laboratory research, however, much remains to be understood about the processes that determine the dynamics of kelp populations, and the subsequent consequences for the diversity and productivity of their associated communities. This limitation is due largely to the fact that processes regulating kelp system productivity, dynamics, and diversity are determined by how different kelp species interact with environmental variability over ecological and evolutionary timescales. In the face of imminent ocean climate change, how will individual kelp taxa respond to rising ocean temperatures or decreasing nutrients? This project will use a combination of laboratory and field studies to understand interactive effects of changing temperature and nutrients on gametogenesis, fertilization, and sporophyte recruitment of kelp. This project will use 9 kelp taxa from California, British Columbia, Australia, Mexico, South Africa, and Chile to test for local adaptation vs. phylogenetic patterns in these traits and to understand whether the level of stress experienced by a population determines regional tolerance patterns. The project will integrate research activities into a novel curriculum at Moss Landing Marine Laboratory and will involve students in laboratory and field studies. These activities will help students to develop good laboratory skills and facilitate the development of critical-thinking as it pertains to the comparative analysis of kelp life histories, conceptual models of life history evolution, and ecological implications of climate change.

Publications resulting from this research:
Demes, K.W., Graham, M.H., and Suskiewicz, T.S. 2009. Phenotypic plasticity reconciles incongruous molecular and morphological taxonomies: The giant kelp, Macrocystis (Laminariales, Phaeophyceae), is a monospecific genus. Journal of Phycology, v.45, p. 1266. doi: 10.1111/j.1529-8817.2009.00752.x

Demes, K. W. and Graham, M. H. 2011. Abiotic regulation of investment in sexual verus vegetative reproduction in the clonal kelp Laminaria sinclairii (Laminariales, Phaeophyceae). Journal of Phycology, v.47. doi: 10.1111/j.1529-8817.2011.00981.x

Henriquez, L.A., Buschmann, A.H., Maldonado, M.A., Graham, M.H., Hernandez-Gonzalez, M.C., Pereda, S.V., and Bobadilla, M.I. 2011. Grazing on giant kelp microscopic phases and the recruitment success of annual populations of Macrocystis pyrifera (Laminariales, Phaeophyceae) in southern Chile. Journal of Phycology, v.47, p. 252. doi: 10.1111/j.1529-8817.2010.00955.x