“The Living Carbon Pump – biological controls of carbon export”
The ocean’s biological carbon pump transfers carbon fixed by phytoplankton from the surface to the deep ocean, playing a central role in regulating Earth’s climate. This lecture explores how sinking marine snow particles drive carbon export and how microbial communities colonizing these particles control their remineralization and the efficiency of carbon sequestration. We will also discuss how zooplankton fragmentation, particle composition, and microbial activity interact to determine how much carbon reaches the deep ocean. Finally, we will discuss why the biological carbon pump has remained remarkably resilient to ecosystem change and whether this resilience will persist under a rapidly changing climate.
“Microbes on particles in the ocean interior”
Particles, essential players in the biological carbon pump, are colonized by microbes and decomposed in one way or another during transit to the oceans’s deep waters. I will review the mechanisms involved in microbial colonization and what the structure of the communities on particles might tell us about particle flux. I will also explore the genomic determinants of particle degradation and the roles of different types of microbes including the crossfeeding between them might have in determining the strength of the carbon pump. “Deconstructing the Martin curve of vertical POC fluxes”
The vertical decrease in organic matter fluxes in the ocean, and its relationship with microbial remineralization, is elegantly represented by an empirical equation known as the Martin curve. Over the last 40 years, this model has been a workhorse in the study of the biological carbon pump, and its wide use has ranged from fitting snapshot regional observations to parameterizing global models. In this talk, I will invite you to identify and critically analyze the many assumptions embodied in this classical model, while introducing an emerging paradigm that highlights the role of poorly understood but potentially important episodic events, particle pools, and biological
interactions in driving the biological carbon pump.

“Proximate and Ultimate drivers of diel vertical migration, and how to 
model them”
Diel vertical migration, the movement of organisms from the surface to depths, is ultimately driven by a fundamental trade-off: animals must access food while minimizing their risk of being eaten. Because organisms cannot directly assess this fitness trade-off—or predation risk as an abstract quantity—they respond to proximate cues such as light, temperature, oxygen, food availability, and predator signals. This lecture will explore these ultimate and proximate drivers, and how they can be represented in models of diel vertical migration. “Life in the Water Column: Diel Vertical Migration and Seasonal 
Variability of Micronekton”
This talk will explore diel vertical migration of micronekton, including fishes, decapods, gelatinous organisms, and cephalopods, using evidence from acoustic observations and net sampling. Particular attention will be given to fishes, highlighting how seasonal variability influences their vertical migration and distribution. The presentation will focus on the changes that occur during the cold season, when environmental conditions can substantially alter the behavior and vertical habitat of several species.