I am thrilled to announce that I will be joining the University of Virginia as an Assistant Professor of Environmental Sciences in the Fall Semester of 2017. Prospective graduate students and postdocs should read about opportunities in the lab or find me at upcoming meetings of ESA, CERF, or WSN.
A new paper, coauthored with colleagues at UC Santa Barbara, UCLA, UC Santa Cruz, and the University of Wisconsin, Milwaukee, has been published in the Proceedings of the Royal Society B. Using sophisticated ocean circulation models and long term measurements of giant kelp abundance and fecundity from satellite data, we have discovered the importance of connectivity to the persistence, extinction, and recovery of giant kelp populations in southern California. Our work also reveals that year-to-year changes in spore production are the most important to successfully rescuing neighboring kelp populations. These findings advance understanding of metapopulation biology broadly, but are also valuable to ocean conservation because they can inform which kelp forests should be prioritized for protection or where coastal restoration efforts could be most effective.
Our results have also been summarized by The UCSB Current.
From left to right: Rachel Simons, Dan Reed, Max Castorani, Dave Siegel, and Tom Bell. Photo credit: Sonia Fernandez
A new paper, led by Harald Hasler-Sheetal and coauthored with Marianne Holmer, Ronnie Glud, and Don Canfield has been published in the journal Environmental Science & Technology. Eutrophication of estuaries and coastal seas is accelerating, increasing light stress on subtidal marine plants and changing their interactions with other species. We undertook the first empirical test of how environmental conditions mediate the metabolic mechanisms underlying species interactions by testing how eutrophication-associated light reductions alter interactions between the a habitat-forming seagrass and a commercially-valuable mussel. Using novel metabolomic analysis, we found cryptic changes to seagrass condition that could not be detected by traditional approaches. Our findings suggest that coastal eutrophication and associated reductions in light may shift seagrass-bivalve interactions from mutualistic to antagonistic, which is important for conservation management of seagrass meadows.
New paper: Native predator chemical cues induce anti-predation behaviors in an invasive marine bivalve
A new paper, coauthored with Kevin Hovel (San Diego State University), has been published in the journal Biological Invasions. We undertook an experiment to test how an invasive mussel responds to chemical cues from several novel native predators. We found that despite limited evolutionary history with native predators, invasive mussels respond with selective anti-predation behaviors and thus are not naïve to the threat of predation from native predators. These results provide new insight to the ‘naïve prey’ hypothesis and help explain the global success of a notorious marine invader. A PDF is available here.
Photo: L. Ilyes
New paper published in JEMBE: Light indirectly mediates bivalve habitat modification and impacts on seagrass
A new paper with collaborators at the University of Southern Denmark (Marianne Holmer, Harald Hasler-Sheetal, and Ronnie Glud) has been published in the Journal of Experimental Marine Biology and Ecology. We undertook experiments to test whether light mediates the impacts of blue mussels on eelgrass in Danish estuaries. We describe how light availability indirectly mediates blue mussel habitat modification by altering plant metabolism, and how these biogeochemical changes feed back to influence eelgrass vulnerability to sulfide stress but not eelgrass performance. Our results suggest that while bivalve effects on seagrasses may be variable (i.e., facilitative, inhibitive, or neutral) in oligotrophic ecosystems, they have the potential to be negative in eutrophic estuaries, which are becoming more prevalent globally. A PDF is available here.
Photo credit: M. Holmer
New paper in press: Connectivity structures local populations dynamics: a long-term empirical test in a large metapopulation system
A new paper with several coauthors at UCSB, UCSC, UCLA, and UW-M is now in press at Ecology. We combined large-scale, long-term, satellite surveys of giant kelp with novel patch-identification methods and oceanographic models to show that connectivity (the movement of kelp spores) strongly predicts local population dynamics by boosting the probability of colonization and reducing the probability of extinction. Our results provide the first comprehensive evidence that southern California giant kelp forests--which are critical coastal habitats in California and worldwide—function as a metapopulation system. A PDF pre-print is available here.
Photo credit: S. Stasi
New paper published in Ecology: Invasive prey indirectly increase predation on their native competitors
A new paper by me and my coauthor Kevin Hovel is now in press at Ecology. In a series of field experiments, we have demonstrated that invasive prey can indirectly increase predation rates on native competitors by changing the behavior of shared native predators. Interestingly, however, the magnitude of apparent competition strongly depends on the vulnerability of natives to predation. A PDF is available here.
Next week I'll be giving at talk at ESA 2014 in the Competition I session on Tuesday at 3:40 PM in Hyatt Regency Ballroom D. For a preview of the talk, follow this link to a blog post I recently authored for the UC Davis Ecology Graduate Student Association: http://bit.ly/1sufLMh
Starting September 2014:
Marine Science Institute
University of California, Santa Barbara
New paper published (Ecology): Disturbance facilitates the coexistence of antagonistic ecosystem engineers in California estuaries
My new paper with coauthors Kevin Hovel, Marissa Baskett, and Susan Williams is now published at Ecology. Through a number of field experiments, we have discovered that competitive coexistence of habitat-modifying species (in this case, seagrass and burrowing shrimp) can be maintained by disturbance and a competition-colonization trade-off. A PDF is available here.