Malcolm Barnard

University of Texas at Austin | UT · Department of Chemistry and Biochemistry

We report 40 metagenomic libraries collected from the Winam Gulf of Lake Victoria during May–July of 2022–2023 and an additional eight opportunistic libraries from adjacent Lakes Simbi, Naivasha, and regional river systems. The sampling period captured cyanobacterial bloom events – shedding insight onto community composition and genomic potential.

Lake Erie, USA–Canada, plays an important ecological and socioeconomic role but has suffered from chronic eutrophication. In particular, western Lake Erie (WLE) is the site of harmful algal blooms (HABs) which are suspected of being driven by excessive nutrient (phosphorus (P) and nitrogen (N)) inputs. During 2022 and 2023, in situ nutrient dilutio...

Dissolved organic matter (DOM) assemblages in freshwater rivers are formed from mixtures of simple to complex compounds that are highly variable across time and space. These mixtures largely form due to the environmental heterogeneity of river networks and the contribution of diverse allochthonous and autochthonous DOM sources. Most studies are, ho...

Optical water quality affects the quantity and spectral composition of underwater light available to photoautotrophs along with light reflected off the water surface. In reservoirs, prominent gradients for optical water quality and clarity measures occur between inlets and outlets, allowing rapid surveys of ecosystem structure across diverse condit...

Coastal North Carolina experienced 36 tropical cyclones (TCs), including three floods of historical significance in the past two decades (Hurricanes Floyd-1999, Matthew-2016 and Florence-2018). These events caused catastrophic flooding and major alterations of water quality, fisheries habitat and ecological conditions of the Albemarle-Pamlico Sound...

Climate change models often assume similar responses to temperatures across the range of a species, but local adaptation or phenotypic plasticity can lead plants and animals to respond differently to temperature in different parts of their range. To date, there have been few tests of this assumption at the scale of continents, so it is unclear if t...

Introduction Dissolved organic matter (DOM) composition varies over space and time, with a multitude of factors driving the presence or absence of each compound found in the complex DOM mixture. Compounds ubiquitously present across a wide range of river systems (hereafter termed core compounds) may differ in chemical composition and reactivity fro...

The Chowan River (CR)-Albemarle Sound Estuary, NC has been plagued by a resurgence of toxigenic cyanobacterial harmful algal blooms (CyanoHABs) since 2015. Both N 2-fixing and Non-N 2-fixing cyanobacteria blooms have occurred in the CR blooms and, in summer 2020, potentially harmful N 2-fixing Dolichospermum spp. was dominant. To identify the nutri...

In addition to obvious negative effects on water quality in eutrophic aquatic ecosystems, recent work suggests that cyanobacterial harmful algal blooms (CHABs) also impact air quality via emissions carrying cyanobacterial cells and cyanotoxins. However, the environmental controls on CHAB-derived aerosol and its potential public health impacts remai...

Zebra Mussels (Dreissena polymorpha) are a highly invasive species that have been invading water bodies around the United States and beyond. This protocol for sample disposal for sample collected from know zebra mussel infested water bodies to prevent spread though local water treatment facilities by bleaching the samples to kill any larvae or othe...

The disclosure describes an algal system for improving water quality through the use of algae. In example embodiments, the algal system comprises an elongate device including algae enclosed therein and capable of reducing at least the levels of nitrates and phosphates in water directed through the device. The algae may be capable of also reducing E...

GeoHealth research both characterizes and predicts problems at the nexus of earth and human systems like climate change, pollution, and natural hazards. While GeoHealth excels in the area of integrated science, there is a need to improve coordinated and networked efforts to produce open science to enable environmental justice. There is a need to re...

This article is composed of three independent commentaries about the state of Integrated, Coordinated, Open, Networked (ICON) principles in the American Geophysical Union Biogeosciences section, and discussion on the opportunities and challenges of adopting them. Each commentary focuses on a different topic: (a) Global collaboration, technology tra...

There is a need for a unified grazing method that can be used across the freshwater-to-marine continuum. To accomplish this, this research utilized dilution grazing assays across the freshwater-to-marine continuum and across the oligotrophic-to-hypereutrophic gradient by measuring size fractions of dilution-based mortality. This was investigated by...

This article provides a commentary about the state of Integrated, equitable outcomes. GeoHealth research both characterizes and predicts problems at the nexus of earth and human systems like climate change, pollution, and natural hazards. While GeoHealth excels in the area of integrated science, there is a need to improve coordinated and networked...

Several experimental designs require serial dilutions of site water. To perform dilutions without the use of prefiltered water or without the addition of nutrients and trace metals in freshwater systems, major ion solutions (MIS) are required. MIS provides a nutrient and metal free dilution medium to minimize hypertonic and hypotonic effects on the...

Cyanobacterial harmful algal bloom (CyanoHAB) proliferation is a global problem impacting ecosystem and human health. Western Lake Erie (WLE) typically endures two highly toxic CyanoHABs during summer: a Microcystis spp. bloom in Maumee Bay that extends throughout the western basin, and a Planktothrix spp. bloom in Sandusky Bay. Recently, the USA a...

Coastal North Carolina experienced 36 tropical cyclones (TCs), including three floods of historical significance in the past two decades (Hurricanes Floyd-1999, Matthew-2016 and Florence-2018). These events caused catastrophic flooding and major alterations of water quality, fisheries habitat and ecological conditions of the Albemarle-Pamlico Sound...

One major threat to freshwater systems is the proliferation of toxic cyanobacterial harmful algal blooms (cyanoHABs). A prolific group of cyanotoxins, the microcystins, is enriched in nitrogen (N), and their synthesis is thought to be linked to N availability. There is a need to investigate the potential roles a major watershed N source; N fertiliz...

The disclosure describes an algal system for improving water quality through the use of algae. In example embodiments, the algal system comprises an elongate device including algae enclosed therein and capable of reducing at least the levels of nitrates and phosphates in water directed through the device. The algae may be capable of also reducing E...

The freshwater alga Spirogyra grevilleana was used in an experimental biofiltration system to reduce levels of Escherichia coli, nitrates, and phosphates. Water collected from a 2.32 ha lake in Atlanta, Georgia, USA was pumped at a constant rate ( m3 hr-1) through the algal filtration devices with low and high concentrations of S. grevilleana. Effl...

The freshwater alga Spirogyra grevilleana was used in an experimental biofiltration system to reduce levels of Escherichia coli, nitrates, and phosphates. Water collected from a 2.32 ha lake in Atlanta, Georgia, USA was pumped at a constant rate (6.17 × 10-1 m3·hr-1) through the algal filtration devices with low and high concentrations of S. grevil...