EAGER: Developing a model for transmission of an infectious disease of marine sponges

University Of Mississippi, University MS

Investigators

Abstract

Diseases of marine invertebrates have been shown to be primary causes of the accelerating destruction of Caribbean coral reef systems. Diseases affecting natural populations threaten biodiversity, resilience and the ecological balance of communities, as well as the ecosystem services they provide. To date, most studies of diseases on reefs have focused on corals, however, reports of sponge diseases have also increased across the globe. On Caribbean reefs, sponges are often a dominant component of the reef biomass,and thus play an important role in the ecology of these ecosystems. The most well described disease affecting Caribbean sponges is Aplysina Red Band Syndrome (ARBS), which affects sponges of the genus Aplysina, resulting in reduced growth, tissue necrosis and breakage at the site of the lesion, particularly during storm events. Understanding how diseases emerge and are transmitted within marine ecosystems is critical for maintaining a healthy level of biodiversity, particularly if we are to gain any predictive power in a rapidly-changing environment. Testing models of disease transmission using extensive field observations and laboratory analyses will contribute to a better understanding of disease processes and developing a transmission model for ARBS requires detailed knowledge about the pathogen-host interaction and pathogen reservoirs in the environment. While a large body of information regarding the ecology and physiology of ARBS-infected sponges is available it is recognized that modeling the transmission dynamics requires a more focused and collaborative approach. This project will develop and test a model of marine disease processes that includes the role of polymicrobial infections, sources and sinks of the pathogen(s), and the ontogeny of this disease within a model host sponge species (Aplysina cauliformis). This novel approach is a high-risk venture (i.e., a timely idea lacking requisite results) with high pay-off potential (i.e., the results will fundamentally enhance our understanding of disease transmission within marine sponges). In this respect, the proposal is appropriate for EAGER funding. The principal investigators will use modern techniques such as high throughput sequencing and incorporate these approaches as a new tools in their laboratories as well as in their undergraduate and graduate courses. Graduate and undergraduate students will also be provided with multidisciplinary hands-on research experiences and will participate in sponge disease surveys to test the newly developed transmission model. Public seminars will be presented to discuss the implications of marine diseases coral reefs and to highlight the potential utility of disease models for the effective management of marine resources. Results from the proposed research will further our knowledge of disease transmission dynamics and enhance our understanding of the role of diseases in the ecology of coral reef ecosystems.