Seagrasses are unique in being the only kinds of flowering plants that live entirely in a marine environment.  Seagrass meadows are of great scientific and practical interest for many reasons. For example, they provide foraging and nursery habitat for many marine species, including sea turtles, fish, diverse invertebrates, and epiphytic algae (e.g., Harbone et al. 2006). They also serve important roles in nutrient cycling in the ocean (Touchette & Burkholder 2000a, Touchette & Burkholder 2000b) and as a physical anchoring system that protects the coastline from the erosive kinetic energy of waves and tides (Christianen et al. 2013). Many seagrass based ecosystems are under severe threats globally (Orth et al. 2006; Waycott et al. 2009) due to factors such as global climate change, pollution, human encroachment, and invasion of exotic species.

We are interested in integrating the long interest in seagrass ecology and ecosystem science with more recent work in microbiology to produce a deeper, more mechanistic understanding of the ecology and evolution of seagrasses and the ecosystems on which they depend. More specifically, we propose to carry out detailed studies of the community of microorganisms that live in and on seagrasses – the seagrass “microbiome”.  We propose to answer a series of fundamental questions about seagrass-microbe interactions that should reveal important information about seagrass ecology, evolution and function.

Our big-picture questions:

• How have the microbial communities associated with seagrasses coevolved with their hosts and what roles, in the past and currently, do microbes play in adaptations of plants to the marine environment?
• What controls the community assembly of the microbiome of Zostera marina, a model seagrass species?
• What role does the microbial community play in the functional ecology of Zostera marina, especially with respect to sulfur and nitrogen metabolism?

The first phase of this project is focused on the collection of microbes associated with Zostera marina, commonly known as eelgrass. We have partnered with ZEN (Zostera Ecological Network) to collect leaf and root tissue, as well as seawater and sediment samples from 25 ZEN 2.0  partner sites from around the world.

The Seagrass Microbiome Project is collaboration among Jonathan Eisen and Jay Stachowicz at the University of  California, Davis and Jessica Green at the University of Oregon, with funding from the Gordon and Betty Moore Foundation.