Publication Date:
2013-11-28
Description:
[1] Chiswell [2013] suggests that some of the conclusions drawn by Behrenfeld et al . [2013] are likely erroneous because of (1) the method used to calculate specific net biomass accumulation rates ( r ; d -1 ) over the seasonal cycle, (2) inconsistencies in the calculation of r and phytoplankton specific cell division rate, μ (d -1 ), and (3) uncertainties in the extrapolation of satellite data to the depth of the seasonal thermocline. Each of these concerns is addressed in the following subsections. We begin with a simple culture-based analogy that clarifies why switching between concentration-based and inventory-based expressions is required for calculating r when the mixed layer varies between shoaling and deepening conditions. This analogy is followed by a more specific mathematical treatment. We then explain why our previous comparisons between r and μ provide a conservative estimate of predator-prey coupling, followed by a discussion of uncertainties in satellite-based assessments of mixed layer phytoplankton biomass.
Print ISSN:
0886-6236
Electronic ISSN:
1944-9224
Topics:
Biology
,
Chemistry and Pharmacology
,
Geography
,
Geosciences
,
Physics
