Project Summary: BIOS-SCOPE is a cross disciplinary program in microbial oceanography with a primary focus on the interactions between microbial processes and DOM concentration and composition. The overarching goal of the BIOS-SCOPE is to form and foster collaborations of cross disciplinary science that utilizes a broad suite of genomic, ecological, oceanographic and biogeochemical approaches to evaluate microbial process, structure and function on various scales. Of particular interest to the BIOS-SCOPE team is better understanding the sources, sinks and transformation of dissolved organic matter (DOM) and the interaction between complex DOM substrates and how they are incorporated, oxidized and transformed by distinct microbial communities at the Bermuda Atlantic Time-series Study (BATS) site.

The BATS site ideally suits the BIOS-SCOPE vision of understanding carbon cycle transitions by applying time-series statistical methods to biological and chemical data, and applying insights gained from metagenomics and plankton cell biology to discover new carbon cycle transformations. DOM biogeochemistry, and its interactions with microbial processes and bacterioplankton phylogenetic diversity, have been studied more intensively and for a longer period (> two decades), than at any other ocean site. At BATS and elsewhere theories have emerged to explain patterns of DOM oxidation. Rapidly expanding genomic data have shown that planktonic ecosystems are intensely competitive, and that that generalist DOM oxidizers (heterotrophic bacterioplankton) don’t fair well in this competition. Theory supported by sparse examples explains patterns in DOM distributions as a consequence of the costs and benefits of specialized metabolism for the harvesting of DOM resources by oxidative cells. DOM may accumulate not because it is intrinsically resistant to biological uptake and oxidation, but because the "economics" of oxidizing the compound vary depending on the depth, season, and the availability of growth factors.

Consequently, DOM quantity as well as its source, distribution and compositional nature are intricately related to the bacterioplankton communities that stratify along gradients of energy and nutrient availability.

These theories are being tested on a technically challenging scientific frontier that merges advances in measuring DOM chemistry and genome analysis with cell biology and field campaigns. The aim of BIOS-SCOPE is to expand knowledge about the BATS ecosystem and gather the new forms of data that are needed to test these ideas. For this purpose we have assembled a cross-disciplinary team including a microbial oceanographer (Carlson- UCSB), a chemist (Kujawinski- WHOI), microbiologist (Giovannoni- OSU), zooplankton ecologists (Maas and Blanco-Bercial- BIOS) and bioinformatician (Temperton- Exeter University) with the expertise and technical acuity that are needed to study complex interactions between food web processes, microbes and DOM quantity and quality in the oligotrophic ocean.