August 1, 2015.
Kelp forests are a very productive marine ecosystem with high species diversity found in many parts of the world, including off the coast of California. As a consequence, they are a major contributor to atmospheric carbon sequestration (storage) on the North American Pacific Coast. However, many kelp forests have been destroyed by the overpopulation of Strongylocentrotus purpuratus (purple sea urchin), which reduce kelp growth, productivity, and species diversity (urchin barrens). The rocky reefs along the southern end of the Santa Monica Bay contain 61.5 hectares of urchin barrens. Organizations are working to remove the urchins and restore kelp forests and monitor the outcome as part of the Palos Verdes Kelp Forest Restoration Project (KFRP). Using this monitoring data, we asked the following questions: (1) has fish species richness increased significantly from the pre- to the post-restoration period? and (2) how much carbon is being stored among the animal life in the pre-restoration period compared to the post-restoration period? Three designation areas were considered: restored kelp forests, urchin barrens (control), existing kelp forests (reference). Two-way ANOVA was used to assess fish species richness. Carbon storage among animal life was calculated by estimating the total biomass of invertebrate and fish species within the three designation areas. Results showed that from the pre-restoration year to the post-restoration year fish species richness increases significantly at all three designation sites. Changes in total biomass of animal life were not statistically significant. While changes were observed, there was wide variability due to small sample sizes for each designation area (N=2). Further data collection and analysis are needed to distinguish if increases are due to KFRP activity or other sources of variation. Further study will determine whether or not the KFRP’s efforts have been effective and can serve as an intervention model for restoring other kelp forests.
California State University, Sacramento (Sac State)
This material is based upon work supported by the Howard Hughes Medical Institute (HHMI). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of HHMI. This work was administered by the Cal Poly Center for Excellence in Science and Mathematics Education (CESAME) and the Fresno State Science and Mathematics Education Center (SMEC) on behalf of the California State University.