Turbulence as a driver for vertical plankton distribution in the subsurface upper ocean

[EN] Vertical distributions of turbulent energy dissipation rates and fluorescence were measured simultaneously with a high-resolution micro-profiler in four different oceanographic regions, from temperate to polar and from coastal to open waters settings. High fluorescence values, forming a deep chlorophyll maximum (DCM), were often located in weakly stratified portions of the upper water column, just below layers with maximum levels of turbulent energy dissipation rate. In the vicinity of the DCM, a significant negative relationship between fluorescence and turbulent energy dissipation rate was found. We discuss the mechanisms that may explain the observed patterns of planktonic biomass distribution within the ocean mixed layer, including a vertically variable diffusion coefficient and the alteration of the cells sinking velocity by turbulent motion. These findings provide further insight into the processes controlling the vertical distribution of the pelagic community and position of the DCM.

Potential vorticity conserving flows and vortex-wave interaction : the role of vertical velocity and isopycnal diffusion on plankton heterogeneity

Programa de doctorado de oceanografía

On the respiratory metabolism of marine plankton: its application in assessing carbon fluxes and the role of substrates in its biochemical control

Programa de doctorado en Oceanografía. La fecha de publicación es la fecha de lectura

Respiratory electron transport activity in plankton: determinants and detection

[ES]La presente tesis, se centra en el estudio del Sistema de Transporte de Electrones (ETS) en organismos del plancton marino, los factores que lo influencian la interpretación de estas mediciones y su detección mediante espectrofotometría y espectrofluorometría, en muestras oceánicas naturales y en cultivos de organismos marinos. Se pudo establecer, la biomasa, la respiración (R) y la respiración potencial (ɸ), en tres transectos en los océanos Índico y Atlántico Norte Sur. A su vez, se determino el estado fisiológico, en tres tamaños del zooplancton, midiendo la relación R/ɸ. Se exploró los efectos de la inanición sobre la R y la variación con respecto a la ɸ en el zooplancton

Starvation's role in plankton metabolism

[EN]Starvation at all scales of plankton from archaea to medusae is the prevailing condition in marine ecosystems. Such nutrient-limitation will shift the physiological state in these organisms with accompanying changes in their physiology and biochemistry. Here, we review our laboratory’s progress in documenting these changes associated with starvation in a range of marine organisms. Specifically, we focused on respiration, ammonium excretion, CO2 production, RQ, respiratory ETS activity, isocitrate dehydrogenase and glutamate dehydrogenase activity in the mysid, Leptomysis lingvura, a dinoflagellate, Oxyrrhis marina and two bacteria, Vibrio natriegens, and Pseudomonas nautica

How Plankton Swim: An Interdisciplinary Approach for Using Mathematics & Physics to Understand the Biology of the Natural World

The authors have developed and field-tested high school-level curricular materials that guide students to use biology, mathematics, and physics to understand plankton and how these tiny organisms move in a world where their intuition does not apply. The authors chose plankton as the focus of their materials primarily because the challenges faced by plankton are novel problems to most students, forcing adoption of new perspectives and making the study of plankton exciting. Additional reasons that they chose plankton to focus on include their ecological importance, their availability to most teachers and students, the ease with which they can be collected and observed, and the current focus of some scientific researchers on their movement and behavior. These curricular materials include a series of inquiry-based, hands-on exercises designed to be accessible to students with a range of backgrounds. Many of these materials could be adapted for use by middle-school, and/or college-level students. In this article, the authors describe sample lessons, summarize what worked well, and flag obstacles they encountered while integrating mathematics and physics into the biology classroom.