Cyanobacterial blooms modify food web structure and interactions in western Lake Erie

Publication date: Available online 16 October 2019Source: Harmful AlgaeAuthor(s): Ruth D. Briland, Joshua P. Stone, Manjunath Manubolu, Jiyoung Lee, Stuart A. LudsinAbstractWith anthropogenic eutrophication and climate change causing an increase in cyanobacterial blooms worldwide, the need to understand the consequences of these blooms on aquatic ecosystems is paramount. Key questions remain unanswered with respect to how cyanobacteria blooms affect the structure of aquatic food webs, the foraging abilities of higher consumers, and the potential for cyanotoxins (e.g., microcystins [MCs]) to accumulate in fish. Toward addressing these uncertainties, physicochemical attributes, water (for MCs), phytoplankton, zooplankton, and epipelagic and benthic age-0 fish were sampled at 75 sites (44 sites for fish) of varying cyanobacteria concentration (0.1–44 μg/L) in western Lake Erie during the cyanobacteria bloom season, 2013–2014. Sites with high cyanobacteria biomass were characterized by Microcystis spp. (84–100% of biomass), detectible levels of MCs (maximum = 10.8 μg/L), and low water transparency (minimum = 0.25 m). Counter to expectations, strong positive relationships were found between cyanobacteria concentration and the biomass of several herbivorous zooplankton taxa (e.g., Daphnia, Diaphanosoma spp., Bosmina (formerly Eubosmina) coregoni, and Calanoida spp.). Expectations regarding fish were partly supported (e.g., diet selectivity varied across a cyan...
Source: Harmful Algae - Category: Environmental Health Source Type: research