Parasites of harmful algal blooms: characterization of cyanophages and chytrids as top-down regulators in Lake Erie

Bibliographic Details
Main Author: McKindles, Katelyn M.
Language:English
Published: Bowling Green State University / OhioLINK 2021
Subjects:
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1616505469449226
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spelling ndltd-OhioLink-oai-etd.ohiolink.edu-bgsu16165054694492262021-08-03T07:16:50Z Parasites of harmful algal blooms: characterization of cyanophages and chytrids as top-down regulators in Lake Erie McKindles, Katelyn M. Biology Planktothrix chytrid cyanophage top-down regulation harmful algae bloom Microcystis Cyanobacterial harmful algal blooms (cHABS) exist as part of a complex ecosystem which includes interactions with both bottom-up (abiotic) and top-down regulators (biotic). Western Lake Erie (Laurentian Great Lakes) is prone to cHABs dominated by Microcystis spp. that often yield microcystin toxin concentrations exceeding the federal EPA recreational contact advisory of 8 μg L-1. Planktothrix agardhii dominates the cHAB community in Sandusky Bay, Lake Erie (USA) from May through September. Here we discuss three studies that focus on the effect of top-down regulators on the annual cyanobacterial harmful algal blooms (cHABs) in the open waters of western Lake Erie and Sandusky Bay as model systems for similar blooms in other regions. Whereas many studies have focused on the factors contributing to the establishment and persistence of cyanobacterial harmful algal blooms (cHABs), this dissertation outlines some of the few studies that have examined bloom pathogenesis. Viral attack on cHABs may contribute to changes in community composition during blooms as well as during bloom decline, yet loss of bloom biomass does not eliminate the threat of cHAB toxin concentrations. Rather, it may increase risks to the public by delivering a pool of dissolved toxin directly into water treatment utilities if the dominating Microcystis spp. is capable of producing microcystins. In addition to viral attacks, chytrid fungi infect cyanobacteria and stimulate food web interactions through manipulation of previously hard to digest filaments and the release of nutrients to support heterotrophic microbes. Infections by the isolated chytrids were specific to Planktothrix planktonic species and were not found on other filamentous cyanobacterial taxa present in Sandusky bay. Even amongst the potential P. agardhii host strains, individual chytrid isolates had different degrees of infectivity and showed preference for different host isolates, suggesting possible ecological partitioning even within the same sample population. Finally, while Planktothrix-specific chytrids have been isolated from bloom events, enumerating chytrids and determining host-pathogen relationships through environmental sampling had yet to be broadly investigated. Planktothrix-specific chytrids were found to be present throughout the bloom season across several years and were occasionally at high enough densities to exert parasitic pressure on their hosts. Taken together, these studies highlight the lesser studied top-down interactions found within cHABs and aim to serve as a starting point for future human health in regards to cyanobacterial toxin release and community ecology projects. 2021-05-20 English text Bowling Green State University / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1616505469449226 http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1616505469449226 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.
collection NDLTD
language English
sources NDLTD
topic Biology
Planktothrix
chytrid
cyanophage
top-down regulation
harmful algae bloom
Microcystis
spellingShingle Biology
Planktothrix
chytrid
cyanophage
top-down regulation
harmful algae bloom
Microcystis
McKindles, Katelyn M.
Parasites of harmful algal blooms: characterization of cyanophages and chytrids as top-down regulators in Lake Erie
author McKindles, Katelyn M.
author_facet McKindles, Katelyn M.
author_sort McKindles, Katelyn M.
title Parasites of harmful algal blooms: characterization of cyanophages and chytrids as top-down regulators in Lake Erie
title_short Parasites of harmful algal blooms: characterization of cyanophages and chytrids as top-down regulators in Lake Erie
title_full Parasites of harmful algal blooms: characterization of cyanophages and chytrids as top-down regulators in Lake Erie
title_fullStr Parasites of harmful algal blooms: characterization of cyanophages and chytrids as top-down regulators in Lake Erie
title_full_unstemmed Parasites of harmful algal blooms: characterization of cyanophages and chytrids as top-down regulators in Lake Erie
title_sort parasites of harmful algal blooms: characterization of cyanophages and chytrids as top-down regulators in lake erie
publisher Bowling Green State University / OhioLINK
publishDate 2021
url http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1616505469449226
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