Evaluation of Toxicity of Algaecide and Released Cyanobacterial Cell Material to Aquatic Organisms Under Rising Surface Water Temperatures

Keywords: algaecide, harmful algal blooms, remote sensing, aquatic toxicology, climate change, algal toxin
Session Type: Virtual Paper Abstract
Day: Tuesday
Session Start / End Time: 3/1/2022 09:40 AM (Eastern Time (US & Canada)) - 3/1/2022 11:00 AM (Eastern Time (US & Canada))
Room: Virtual 34

Abstract

Due to global warming and cultural eutrophication, many surface water bodies have been experiencing elevated surface water temperatures and nutrient loads, conditions that can instigate more frequent and toxic harmful algal or cyanobacterial blooms (cyanoHABs). But cyanoHABs can cause human health problems and deteriorate aquatic ecosystems. This project focuses on not only spatial and temporal analysis of cyanoHABs and temperature through remote sensing, but also on how the toxicity of a cyanobacterial species, Microcystis aeruginosa, may change with increased surface water temperature and affect test organisms. It also looks at how mortality rates of test organisms may change when exposed to a common algaecide, hydrogen peroxide, at the same increased temperatures. In-vivo acute, 48-hour EPA WET method toxicity tests with aquatic indicator species, Ceriodaphnia dubia, have been performed in triplicate with algaecide at water temperatures of 25 degrees Celsius, producing an average LC50 of 3.63 mg/L. Experimentation with cyanobacterial extracts have also been performed at 25 degrees Celsius, with an average LC50 of 1056 ug/L. Future experiments with the algaecide and toxin extracts will be performed at 27 degrees Celsius and are predicted to produce different LC50 values due to temperature sensitivity. This project aims to better understand how temperature and algaecide affect toxicity and mortality of test organisms in order to provide guidance for future cyanoHAB mitigation.