Project Funding: 2007 - 2010

NRA: 2006 NASA: Interdisciplinary Research in Earth Science   

Funded by NASA

Abstract:
Forests of giant kelp (Macrocystis spp.), found on shallow subtidal temperate reefs throughout the world, are some of the most productive ecosystems in the world. Kelp forests have great economic value and are harvested for use in products ranging from pharmaceuticals to aquaculture feed. More importantly, giant kelp is an "ecosystem engineer" providing both food and habitat to a diverse array of biologically and commercially important species of algae, invertebrates, fish, and marine mammals while exporting large quantities of organic matter to adjacent littoral and continental shelf ecosystems. Economic analyses show revenues associated with California kelp forests of > $250 million per year. We propose to develop a predictive understanding of giant kelp forests in the nearshore waters of California using a combination of... * High-resolution remote sensing of kelp cover, biomass & its physiological state, * Metapopulation modeling of kelp patch dynamics, and * Bio-optical modeling of kelp productivity. The integration of these approaches will produce a unified assessment of kelp dynamics that can be determined using available satellite data. This proposed work takes advantage of the recent availability of high resolution, multispectral SPOT imagery to map kelp cover dynamics on spatial scales of 10 m at monthly time intervals (see www.spot.ucsb.edu). Using SPOT multispectral imagery, we will develop new measures of kelp canopy cover, biomass, productivity and canopy condition. These data will enable us to examine the role of disturbance and other environmental factors such as surface wave stress (using regional wave models), coastal currents (using HF radar remote sensing), sediment plumes (using MODIS & SeaWiFS ocean color imagery) and nutrient availability (using field and remote sensing proxies) on our high resolution observations of kelp canopy cover and biomass. Using these observations, metapopulation models of kelp patch dynamics as well as bio-optical models of optical kelp productivity can be implemented and coupled. Our goal is to use this bottom-up synthesis of the ecological processes driving kelp dynamics to develop a unified remote assessment of kelp dynamics for the nearshore waters off California. This work has a multitude of real-world applications including the ecological assessment of marine protected areas that have been recently designated around the Channel Islands National Marine Sanctuary and other California marine protected areas including the emerging state-mandated network of marine reserves along the California coast. As such, we will collaborate with the NOAA Channel Islands National Marine Sanctuary (http://www.cinms.nos.noaa.gov/), the Santa Barbara Coastal Long Term Ecological Research project (http://sbc.lternet.edu/; NSF support), and the Coastal Data Information Project (http://cdip.ucsd.edu/; USGS & State of California support).

Publications:

ALBERTO, F., RAIMONDI, P. T., REED, D. C., WATSON, J. R., SIEGEL, D. A., MITARAI, S., COELHO, N., SERRAO, E. A. 2011. Isolation by oceanographic distance explains genetic structure for Macrocystis pyrifera in the Santa Barbara Channel. Molecular Ecology. 20(12), 2543-2554. DOI: 10.1111/j.1365-294x.2011.05117.x

BYRNES, J. E., REED, D. C., CARDINALE, B. J., CAVANAUGH, K. C., HOLBROOK, S. J., SCHMITT, R. J. 2011. Climate-driven increases in storm frequency simplify kelp forest food webs. Global Change Biology. 17(8), 2513-2524. DOI: 10.1111/j.1365-2486.2011.02409.x

Cavanaugh, K. C., Kendall, B. E., Siegel, D. A., Reed, D. C., Alberto, F., Assis, J. 2013. Synchrony in dynamics of giant kelp forests is driven by both local recruitment and regional environmental controls. Ecology. 94(2), 499-509. DOI: 10.1890/12-0268.1

Cavanaugh, K., Siegel, D., Kinlan, B., Reed, D. 2010. Scaling giant kelp field measurements to regional scales using satellite observations. Marine Ecology Progress Series. 403, 13-27. DOI: 10.3354/meps08467

Cavanaugh, K., Siegel, D., Reed, D., Dennison, P. 2011. Environmental controls of giant-kelp biomass in the Santa Barbara Channel, California. Marine Ecology Progress Series. 429, 1-17. DOI: 10.3354/meps09141

Reed, D. C., Rassweiler, A., Carr, M. H., Cavanaugh, K. C., Malone, D. P., Siegel, D. A. 2011. Wave disturbance overwhelms top-down and bottom-up control of primary production in California kelp forests. Ecology. 92(11), 2108-2116. DOI: 10.1890/11-0377.1

2008 NASA Carbon Cycle & Ecosystems Joint Science Workshop Posters

• Remote Sensing Assessment of Kelp Forest Productivity   --   (Richard C Zimmerman, Heidi M Dierssen, W Paul Bissett, Victoria J Hill)   [abstract]

More details may be found in the following project profile(s):

• NASA Biological Diversity & Ecological Conservation (BDEC) Project Profile