Characterization of the Sandusky Bay Planktothrix agardhii bloom of 2015 utilizing metatranscriptomi

Session: Harmful Algal Blooms: From Ecosystem Drivers to Ecosystem Impacts (3)

Michelle Neudeck, Bowling Green State University, [email protected]
Robert (Mike) McKay, University of Windsor, [email protected]
George Bullerjahn, Bowling Green State University, [email protected]

Abstract

The Planktothrix HABs of Lake Erie’s Sandusky Bay have been increasing in duration in the last decades, yielding microcystin concentrations that routinely exceed recreational contact advisories.  Dissolved inorganic N concentrations increase following large rain events, but rapidly decrease due to denitrification during dry periods, yielding very low dissolved N:P ratios in late summer.  We performed metatranscriptomic analyses of Sandusky Bay during 2015 to better understand N metabolism of the non-diazotrophic Planktothrix agardhii bloom during N depletion.  The transcripts of the GS-GOGAT system and ammonium transporters increase during nitrogen limitation, reflecting the increasing dependence on ammonium regeneration in late summer (Hampel et al., 2019, JGLR). Mobilization of internal N sources through phycobilisome degradation is also detected as N:P ratios approach unity. The transcripts for phosphate regulation increase during periods of P limitation. Understanding how Planktothrix adapt to shifts in N and P bioavailability will impact the development of future environmental policies in regards to agricultural applications.

Twitter handle of presenter
@MichelleNeudeck