Marine Laboratory on the shore of Pago Bay on Guam’s east coast.

The Bentlage Lab at the University of Guam studies the processes that shaped the history of cnidarians (hydroids, jellyfish, corals and their kin) and govern their present-day distributions and ecology. We use phylogenetic systematics and comparative methods to address questions on evolutionary time-scales. Having ready access to coral reefs around the island of Guam, we have begun investigating the interactions between the environment and the dominant benthic cnidarians, corals to understand how fluctuations in environmental parameters affect cellular-level processes in corals. Corals are organisms comprised of a marine invertebrate host, photosynthetic unicellular “algae” and a microbial community, collectively referred to as the coral holobiont. At present, we use genomic (transcriptome sequencing, genome sequencing, and metabarcoding) and biochemical (PAM fluorometry and flow cytometry) tools to study the coral holobiont community under stress.

Gab Gab reef in Apra Harbor dominated by Porites rus, a stress-resilient coral.

Guam experienced almost annual episodes of coral bleaching starting in 2013. These bleaching events led to significant declines in coral cover. In addition to bleaching stress driven by global climate change and associated increased sea surface temperatures, Guam’s reefs experience a variety of local stresses that significantly affect coral communities in near-shore waters. For example, slash and burn hunting practices and urban development have led to declines in plant cover in our watersheds and consequently increased run-off of terrestrial sediments onto our fringing and barrier reefs. We are interested in better understanding the interplay of local and global stressors in shaping coral health and resilience. We hope that a better understanding of combined local and global effects will aid in predicting the coral communities of the future, changes in ecosystem services, and prioritization of restoration efforts by local stakeholders.