Viral and microbial mediated processes dominate the biosphere. Or do they? In practice, we really don't know because the rates of viral and microbial processes in the environment are very hard to determine. Challenges in getting accurate flux measurements range from low abundances to non-standard metabolism to difficulty in access (e.g., deep sea and subsurface environments). The goal of this meeting will be to discuss conventional and emerging technologies (e.g., highly sensitive micro-calorimetry, photonic based microcalorimetry, etc) that can improve flux measurements. Engineers and scientists interested in these tools are invited to present their instrumentation. Microbial ecologists are encouraged to bring rationale/hypotheses that would require new instrumentation. All participants are also encouraged to bring viral and microbial flux data workshop how calorimetric data will be incorporated into microbial ecology models.