title: Underwater microscopy for in situ studies of benthic ecosystems.
abstract: Microscopic-scale processes significantly influence benthic marine ecosystems such as coral reefs and kelp forests. Due to the ocean's complex and dynamic nature, it is most informative to study these processes in the natural environment yet it is inherently difficult. Here we present a system capable of non-invasively imaging seafloor environments and organisms in situ at nearly micrometre resolution. We overcome the challenges of underwater microscopy through the use of a long working distance microscopic objective, an electrically tunable lens and focused reflectance illumination. The diver-deployed instrument permits studies of both spatial and temporal processes such as the algal colonization and overgrowth of bleaching corals, as well as coral polyp behaviour and interspecific competition. By enabling in situ observations at previously unattainable scales, this instrument can provide important new insights into micro-scale processes in benthic ecosystems that shape observed patterns at much larger scales.
authors.affiliation: Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Mullen
authors.affiliation: School of Marine Sciences, University of Haifa, Haifa 3498838, Israel.
authors.forename: Tali
authors.initials: T
authors.lastname: Treibitz
authors.affiliation: Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA.
authors.forename: Paul L D
authors.initials: PLD
authors.lastname: Roberts
authors.affiliation: Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA.
authors.forename: Emily L A
authors.initials: ELA
authors.lastname: Kelly
authors.affiliation: The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900, Israel.|The Interuniversity Institute for Marine Sciences, Eilat 88103, Israel.
authors.forename: Rael
authors.initials: R
authors.lastname: Horwitz
authors.affiliation: Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA.
authors.forename: Jennifer E
authors.initials: JE
authors.lastname: Smith
authors.affiliation: Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA.
authors.forename: Jules S
authors.initials: JS
authors.lastname: Jaffe