OCE-PRF: How larval behavior and microbes govern the assembly of Caribbean coral communities

Marhaver Kristen L, Merced CA

Investigators

Abstract

During dispersal, larvae of many marine species benefit from the richly detailed, site-specific navigational information provided to them by microbes (Bacteria and Archaea) in the water column and on surfaces. On the benthos, microbial communities may stress settling larvae and increase mortality. This threat is reduced if a species can evolve to detect cues from high-mortality environments and navigate away from them. Previous work by the PI using a spawning Caribbean coral species demonstrated that coral reef microbial communities affect both larval settlement and survival; larvae exposed to water collected near conspecific adult corals suffered higher mortality and lower settlement rates. This species may have evolved to detect and avoid the microbes near conspecific adults, due to the increased risk of mortality from host-specific pathogens. Could this be a general phenomenon governing the assembly of coral communities? Under current NSF funding, the PI has also isolated and identified the first cultured bacteria that induce larval settlement in a Caribbean coral species. The proposed project will be conducted at CARMABI Foundation Research Station in Curacao with sponsoring scientist Dr. Mark Vermeij. The PI will use swimming-stage coral larvae of multiple species in laboratory and field experiments to investigate how microbial community heterogeneity on coral reefs provides information to settling corals. Intellectual Merit: Coral reefs provide humans with billions of dollars in goods and services each year through fisheries, tourism, and cultural value, yet they are massively threatened by human activity. As adult corals die at increasing rates, the persistence of the world's coral reefs will depend increasingly on successful recruitment by juvenile corals. This study will therefore advance knowledge of a crucial behavior in an ecologically significant group of marine organisms while testing the generality of a novel ecological hypothesis: that coral larvae have evolved to use microbial communities as navigational information to detect conspecifics. Products will include new knowledge about coral recruitment patterns and specific knowledge about bacteria that induce settlement. Broader Impacts : Reef health: Settlement-inducing bacterial strains will be provided to reef restoration groups in the Caribbean, thus increasing the rate at which they can raise, settle, and outplant juvenile corals to speed the recovery of degraded reefs. Training and broadening participation: For students in underrepresented groups to successfully compete for Ph.D. programs and funding, access to mentorship, research training, and fieldwork experiences are critical. Yet these opportunities are often limited to students who can afford to volunteer or pay out-of-pocket. To address this problem, the project will bring two to three U.S. undergrad/Master's students from underrepresented groups to the study site in Curacao each year for their first hands-on training in reef ecology and field research. Communication: Research results will be shared across Curacao through public lectures, news interviews, and via CARMABI's nature education program, which reaches 14,000 Curacaoan schoolchildren yearly. Beyond Curacao, the PI will continue to pursue creative communication projects. As a TED Global Fellow, she will produce an animated segment about biodiversity in collaboration with TED-Ed and give a TED Talk specifically about promoting diversity in ocean science. TED is a nonprofit devoted to sharing ideas and bringing people together from technology, entertainment, and design (www.ted.com). This postdoctoral fellowship is managed by the Division of Ocean Sciences and funded by the International Science and Engineering Section of the Office of International and Integrative Activities.