title: Microbial ecology of four coral atolls in the Northern Line Islands.
abstract: Microbes are key players in both healthy and degraded coral reefs. A combination of metagenomics, microscopy, culturing, and water chemistry were used to characterize microbial communities on four coral atolls in the Northern Line Islands, central Pacific. Kingman, a small uninhabited atoll which lies most northerly in the chain, had microbial and water chemistry characteristic of an open ocean ecosystem. On this atoll the microbial community was equally divided between autotrophs (mostly Prochlorococcus spp.) and heterotrophs. In contrast, Kiritimati, a large and populated ( approximately 5500 people) atoll, which is most southerly in the chain, had microbial and water chemistry characteristic of a near-shore environment. On Kiritimati, there were 10 times more microbial cells and virus-like particles in the water column and these microbes were dominated by heterotrophs, including a large percentage of potential pathogens. Culturable Vibrios were common only on Kiritimati. The benthic community on Kiritimati had the highest prevalence of coral disease and lowest coral cover. The middle atolls, Palmyra and Tabuaeran, had intermediate densities of microbes and viruses and higher percentages of autotrophic microbes than either Kingman or Kiritimati. The differences in microbial communities across atolls could reflect variation in 1) oceaonographic and/or hydrographic conditions or 2) human impacts associated with land-use and fishing. The fact that historically Kingman and Kiritimati did not differ strongly in their fish or benthic communities (both had large numbers of sharks and high coral cover) suggest an anthropogenic component in the differences in the microbial communities. Kingman is one of the world's most pristine coral reefs, and this dataset should serve as a baseline for future studies of coral reef microbes. Obtaining the microbial data set, from atolls is particularly important given the association of microbes in the ongoing degradation of coral reef ecosystems worldwide.
authors.affiliation: Department of Biology, San Diego State University, San Diego, California, USA. Elizabeth_dinsdale@hotmail.com
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Dinsdale
authors.forename: Olga
authors.initials: O
authors.lastname: Pantos
authors.forename: Steven
authors.initials: S
authors.lastname: Smriga
authors.forename: Robert A
authors.initials: RA
authors.lastname: Edwards
authors.forename: Florent
authors.initials: F
authors.lastname: Angly
authors.forename: Linda
authors.initials: L
authors.lastname: Wegley
authors.forename: Mark
authors.initials: M
authors.lastname: Hatay
authors.forename: Dana
authors.initials: D
authors.lastname: Hall
authors.forename: Elysa
authors.initials: E
authors.lastname: Brown
authors.forename: Matthew
authors.initials: M
authors.lastname: Haynes
authors.forename: Lutz
authors.initials: L
authors.lastname: Krause
authors.forename: Enric
authors.initials: E
authors.lastname: Sala
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Sandin
authors.forename: Rebecca Vega
authors.initials: RV
authors.lastname: Thurber
authors.forename: Bette L
authors.initials: BL
authors.lastname: Willis
authors.forename: Farooq
authors.initials: F
authors.lastname: Azam
authors.forename: Nancy
authors.initials: N
authors.lastname: Knowlton
authors.forename: Forest
authors.initials: F
authors.lastname: Rohwer
mesh_terms: D000820:Animal Diseases / Q000382:microbiology; D000818:Animals; D037421:Anthozoa / Q000382:microbiology*; D017753:Ecosystem; D005843:Geography; D006801:Humans; D008386:Marine Biology; D014867:Water / Q000737:chemistry; D014871:Water Microbiology
chemical_list: D014867:Water