New research, published in the Proceedings of the National Academy of Sciences (PNAS) has uncovered how kelp forests shape beach food webs and ecosystem dynamics. The study was recently published by Jonathan Walter (CWS Senior Researcher, lead author), Kyle A. Emery, Jenifer E. Dugan, David M. Hubbard, Tom W. Bell, Lawrence W. Sheppard, Vadim A. Karatayev, Kyle C. Cavanaugh, Daniel C. Reuman, and Max C. N. Castorani.

Leveraging 11 years of long-term data from UC Santa Barbara's Santa Barbara Coastal Long Term Ecological Research (LTER) site, the team modeled wind, wave, kelp wrack, and beach width data at 5 beaches to understand the role of synchrony in the beach food web. The team discovered that kelp forest biomass and beach width are biggest drivers of kelp wrack on beaches, and that this synchrony has a time-lag. For example, when ocean dynamics influence an increase in kelp wrack on beaches, it in time increases small shore invertebrate abundance; this increase in food source subsequently increases the abundance of predatory shorebirds. Indeed this synchronization of food subsidies across the reef and beach ecosystems demonstrates previously unappreciated ways in which these ecosystems are connected. 

“The amount of kelp on the reef changes through time in a way where the peaks and low points in abundance across several kelp forests are matched together. That’s what we refer to as synchrony. It is related to the ability of systems to persist in the face of changing environmental conditions. A little asynchrony allows systems to be resistant to fluctuations and therefore more stable.” – Jonathan Walter, lead author & senior researcher at the Center for Watershed Sciences

View the press release: The Choreography Connecting Kelp Forests to the Beach, by UC Santa Barbara/UC Davis News and Media Relations. January 03, 2024. 

View the publication: Walter, J.A., Emery, K.A., Dugan, J.E., Hubbard, D.M., Bell, T.W., Sheppard, L.W., Karatayev, V.A., Cavanaugh, K.C., Reuman, D.C. and Castorani, M.C., 2024. Spatial synchrony cascades across ecosystem boundaries and up food webs via resource subsidies. Proceedings of the National Academy of Sciences, 121(2), p.e2310052120.