Collaborative Research: Physiological mechanisms involved in the allocation of energy to reproduction in corals under thermal stress

University Of Washington, Seattle WA

Investigators

Abstract

Coral reefs are diverse tropical ecosystems that provide storm protection and support economic livelihoods for fishing and tourism in coastal communities. The long-term health of reefs worldwide is being negatively impacted by increased seawater temperatures that have led to coral bleaching and widespread coral mortality, especially during the last three years. The goal of this research is to identify characteristics and physiological strategies that lead to successful coral reproduction and long-term recovery despite bleaching. This information can be applied to coral conservation and management efforts. Furthermore, these findings will be incorporated into community outreach activities, as follows: in Hawaii, to develop a workshop with elementary teachers from Hawaiian immersion schools; in Washington, with Seattle MESA (Mathematics Engineering Science and Achievement for underrepresented minorities, women, at-risk and economically disadvantaged youth) to connect science fundamentals to the real world and work with teachers to develop marine biology lesson plans; and in Pennsylvania, with the School District of Philadelphia to develop hands-on classroom activities and lead field trips to the local ocean with underserved high schools populated by over 90% minority students. Most prior coral bleaching studies have focused on the potential of adult colonies to recover and acclimatize from stress. However, future reefs will not only require the survival of adults, but will also be dependent upon the continuation of sexual reproduction despite thermal stress. Little is known about the mechanisms corals use to tolerate and successfully reproduce in stressful environments. This interdisciplinary study will characterize the physiological and phenotypic responses associated with thermal stress and quantify the impacts of coral nutrition to reproduction. The research will focus on an important and dominant reef builder in Hawaii that has the capacity to sexually reproduce despite bleaching. The objectives are to: (1) independently track the contribution of carbon and nitrogen acquired from parental photosynthesis and heterotrophy to gamete development in bleached and unbleached colonies; (2) develop nutritional proteome profiles of bleached and unbleached parental colonies and their eggs that have relied on different trophic sources throughout gamete development; and (3) use the proteomic surveys to develop a biomarker assay for coral trophic status. The findings of this study will detect biomarkers that can serve to monitor trophic status and identify coral species that are likely to recover and reproduce after a bleaching event. Altogether these data can be applied to conservation and management efforts and the development of accurate forecasting models.