John Beardall

Monash University (Australia) · School of Biological Sciences, Clayton

Marine microalgae demonstrate a notable capacity to adapt to high CO2 and warming in the context of global change. However, the dynamics of their evolutionary processes under simultaneous high CO₂ and warming conditions remain poorly understood. Here, we analyze the dynamics of evolution in experimental populations of a model marine diatom Phaeodac...

Photosynthetic organisms have an enormous influence on our environment through their effects on the development of other life on Earth and the way they alter the planet's geology and geochemistry. This book takes a unique approach by examining the evolutionary history of the major groups of aquatic photoautotrophs in the context of the ecophysiolog...

Photosynthetic organisms have an enormous influence on our environment through their effects on the development of other life on Earth and the way they alter the planet's geology and geochemistry. This book takes a unique approach by examining the evolutionary history of the major groups of aquatic photoautotrophs in the context of the ecophysiolog...

Photosynthetic organisms have an enormous influence on our environment through their effects on the development of other life on Earth and the way they alter the planet's geology and geochemistry. This book takes a unique approach by examining the evolutionary history of the major groups of aquatic photoautotrophs in the context of the ecophysiolog...

Photosynthetic organisms have an enormous influence on our environment through their effects on the development of other life on Earth and the way they alter the planet's geology and geochemistry. This book takes a unique approach by examining the evolutionary history of the major groups of aquatic photoautotrophs in the context of the ecophysiolog...

Photosynthetic organisms have an enormous influence on our environment through their effects on the development of other life on Earth and the way they alter the planet's geology and geochemistry. This book takes a unique approach by examining the evolutionary history of the major groups of aquatic photoautotrophs in the context of the ecophysiolog...

The marine microalga Emiliania huxleyi is widely distributed in the surface oceans and is prone to infection by coccolithoviruses that can terminate its blooms. However, little is known about how global change factors like solar UV radiation (UVR) and ocean warming affect the host‐virus interaction. We grew the microalga at 2 temperature levels wit...

Trade-offs play vital roles in evolutionary theory, linking organism performance to changing environments in the context of global change. Marine microalgae, as one of the most important groups of primary producers in the biosphere, exhibit significant trade-offs across multiple traits in response to environmental changes, such as elevated CO2 (and...

Microalgae are gaining considerable attention in the field of cosmeceuticals due to their unique profile. In particular, the diverse range of valuable bioactive compounds isolated from microalgae are known to exhibit multiple properties, including anti-aging, antioxidant, whitening, moisturising, and photoprotection, which have contributed to their...

Although the diverse impacts of elevated dissolved CO2 and warming on organisms within various trophic levels in marine food webs are well documented, we have yet to explore the biological links across different levels of biological organization from primary producers to secondary producers on an evolutionary time scale in a high‐CO2 ocean. Here, w...

Respiratory activity in the oceans is declining due to the expansion of hypoxic zones and progressive deoxygenation, posing threats to marine organisms along with impacts of concurrent ocean acidification. Therefore, understanding the combined impacts of reduced pO2 and elevated pCO2 on marine primary producers is of considerable significance. Here...

With the present day rise of interest in acquiring sustainability in the pharmaceutical industry, there has been an emphasis on finding natural resources to replace the use of synthetic compounds used in products. Microalgae have garnered significant attention owing to their natural and sustainable capability to produce a diverse array of bioactive...

Blooms of microalgal red tides and macroalgae (e.g., green and golden tides caused by Ulva and Sargassum ) have caused widespread problems around China in recent years, but there is uncertainty around what triggers these blooms and how they interact. Here, we use 30 years of monitoring data to help answer these questions, focusing on the four main...

Under global change scenarios, the sea surface temperature is increasing steadily along with other changes to oceanic environments. Consequently, marine diatoms are influenced by multiple ocean global change drivers. We hypothesized that temperature rise mediates the responses of polar and temperate diatoms to UV radiation (UVR) to different extent...

Ocean warming is suggested to exert profound effects on phytoplankton physiology and growth. Here, we investigated how the coccolithophore Emiliania huxleyi (BOF 92, a non-calcifying strain) responded to changes in temperature in short- and long-term thermal treatments. The specific growth rate after 10 days of acclimation increased gradually with...

Genetic changes together with epigenetic modifications such as DNA methylation have been demonstrated to regulate many biological processes and thereby govern the response of organisms to environmental changes. However, how DNA methylation might act cooperatively with gene transcription and thereby mediate the long-term adaptive responses of marine...

The marine picocyanobacterium Synechococcus accounts for a major fraction of the primary production across the global oceans. However, knowledge of the responses of Synechococcus to changing pCO2 and light levels has been scarcely documented. Hence, we grew Synechococcus sp. CB0101 at two CO2 concentrations (ambient CO2 AC:410 μatm; high CO2 HC:100...

Planète bleue, photosynthèse rouge et verte décrit les mécanismes qui permettent aux organismes photosynthétiques aquatiques de contribuer pour moitié à la productivité primaire nette, d’atténuer les changements climatiques en séquestrant le dioxyde de carbone et, par la production d’oxygène, d’avoir transformé l’atmosphère anoxique originelle de l...

Planète bleue, photosynthèse rouge et verte décrit les mécanismes qui permettent aux organismes photosynthétiques aquatiques de contribuer pour moitié à la productivité primaire nette, d’atténuer les changements climatiques en séquestrant le dioxyde de carbone et, par la production d’oxygène, d’avoir transformé l’atmosphère anoxique originelle de l...

A subtropical clone of Gephyrocapsa oceanica was grown over the temperature and salinity range 10–30°C and 20‰–45‰ respectively. Cellular DMSP increased with increasing salinity, compatible with the hypothesis that DMSP is a compatible osmolyte. Cellular DMSP content was highest at colder temperatures and decreased as temperature increased. Net DMS...

The projected ocean acidification (OA) associated with increasing atmospheric CO 2 alters seawater chemistry and hence the bio-toxicity of metal ions. However, it is still unclear how OA might affect the long-term resilience of globally important marine microalgae to anthropogenic metal stress. To explore the effect of increasing p CO 2 on copper m...

The possession of a carbon concentrating mechanism (CCM) by a given phytoplankton species will in part determine its response to changes in the dissolved inorganic carbon concentrations in the global ocean. Earlier work on CCMs in the coccolithophore Emiliania huxleyi suggested that this species did not possess a CCM, though more recent studies ind...

Sustainable management of estuaries depends on understanding the synergistic effects of nutrients and hydrological factors on estuarine food webs. We examined how phytoplankton, zooplankton and selected fish larval counts (Acanthopagrus butcheri, black bream) vary in relation to groundwater inputs and environmental flow releases (EFRs) in a small,...

Although high CO2 and warming could act interactively on marine phytoplankton, little is known about the molecular basis for this interaction on an evolutionary scale. Here we explored the adaptation to high CO2 in combination with warming in a model marine diatom Phaeodactylum tricornutum. Whole-genome re-sequencing identifies, in comparison to po...

To understand how seasonal factors could drive the formation of green tide blooms and their flotation and decay, we cultured the green tide algal species Ulva prolifera at various temperatures (5, 10, 15, 20, 25, 30, and 35 °C) and light intensities (40, 80, 140, 240, and 400 μmol photons m⁻² s⁻¹). The results showed that the ratio of floating U. p...

CRISPR/Cas9 technology is one of the common methods of genome editing and targeted gene mutation, which has recently been used for manipulating microalgae such as Chlamydomonas reinhardtii. Besides, this technology can play a role in the fight against greenhouse gases (e.g., carbon dioxide) production by studying genetic pathways to improve algal s...

Increasing atmospheric CO 2 concentration due to human activities is responsible for global warming and ocean warming, the latter enhancing stratification and shoaling of the upper mixed layer. Marine primary producers account for about half of global photosynthetic carbon fixation. Global change affects both marine and freshwater ecosystems. Howev...

Focusing on the cyanobacteria and microalgae which globally are responsible for the bulk of aquatic photosynthesis, this chapter addresses the main abiotic factors controlling biosynthetic processes within cells and therefore the elemental and macromolecular composition of photoautotrophs in balance with the environment. It explores the main nutrie...

Extracellular signals are reported to mediate chemical cross‐talk among pelagic microbes, including microalgal prey and predators. Water soluble mediator compounds play a crucial role in extracellular communication which is vital for prey recognition, attraction, capture and predator deterrence. A range of exo‐metabolites including oxylipins and vi...

The atmospheric concentration of CO2 is steadily increasing and causing climate change. To achieve the Paris 1.5 or 2°C target, negative emission technologies must be deployed in addition to reducing carbon emissions. The ocean is a large carbon sink but the potential of marine primary producers to contribute to carbon neutrality remains unclear. H...

Among efforts to explore ways to achieve carbon neutrality globally or regionally, photosynthetic carbon sequestration by algae has been identified as having immense potential. Algae play a crucial role in providing the base of aquatic ecosystems, driving important biogeochemical cycles in oceans and freshwaters and, in so doing, act as a critical...

Defining the physiological traits that characterise phytoplankton involves comparison with related organisms in benthic habitats. Comparison of survival time in darkness under natural conditions requires more information. Gas vesicles and flagella as mechanisms of upward movement relative to surrounding water, allowing periodic vertical migration,...

Many marine organisms are exposed to decreasing O2 levels due to warming-induced expansion of hypoxic zones and ocean deoxygenation (DeO2). Nevertheless, effects of DeO2 on phytoplankton have been neglected due to technical bottlenecks on examining O2 effects on O2-producing organisms. Here we show that lowered O2 levels increased primary productiv...

Phytoplankton are responsible for nearly half of global primary productivity and play crucial roles in the Earth’s biogeochemical cycles. However, the long‐term adaptive responses of phytoplankton to rising CO2 remains unknown. Here we examine the physiological and proteomics responses of a marine diatom, Phaeodactylum tricornutum, following long‐t...

The use of culture media and sterile technique involving flaming of equipment in order to maintain unialgal or aseptic conditions is standard laboratory practice. However, as a result, atmospheric CO2 concentrations, especially within laminar flow units but also in the laboratory as a whole, can become quite elevated. Media exposed in these conditi...

Much has been published on the effects of ocean acidification on plankton since the original Royal Society 2005 report. In addition to direct effects on primary production, it is clear that ocean acidification also has profound consequences for biogeochemistry. Furthermore, although ocean acidification can have direct effects of on grazers such as...

In the warm, oligotrophic oceans, phytoplankton frequently experience high light exposure and must compete for a potentially limited nutrient supply. Additionally, the light regimes are dynamic in view of the diel solar cycle, weather conditions, and depth. Dealing with these challenges is critical to their survival. Here, we explored, using active...

Redox metabolism is integral to the functioning of photosynthetic organisms. The highly oxidative reactive oxygen species (ROS) are products of cellular redox processes and can cause major cellular damage. ROS are also produced in the face of environmental and cellular stress, including metal-induced oxidative stress. The degree of ROS production a...

While intertidal macroalgae are exposed to drastic changes in solar photosynthetically active radiation (PAR) and ultraviolet radiation (UVR) during a diel cycle, and to ocean acidification (OA) associated with increasing CO2 levels, little is known about their photosynthetic performance under the combined influences of these drivers. In this work,...

The release of anthropogenic organic pollutants has resulted in extensive environmental risks to coastal waters. Among pollutants released, the most common antifoulant, Irgarol 1051, is an effective inhibitor of photosystem II of photoautotrophs; thus, the continuous release of this compound into surrounding seawater would potentially threaten mari...

Salinity is one of the significant factors that affect growth and cellular metabolism, including photosynthesis and lipid accumulation, in microalgae and higher plants. Microchloropsis gaditana CCMP526 can acclimatize to different salinity levels by accumulating compatible solutes, carbohydrates, and lipids as energy storage molecules. We used prot...

Experimentally elevated pCO2 and the associated pH drop are known to differentially affect many aspects of the physiology of diatoms under different environmental conditions or in different regions. However, contrasting responses to elevated pCO2 in the dark and light periods of a diel cycle have not been documented. By growing the model diatom Pha...

Atmospheric CO2 is increasing at unprecedented rates, with modelling studies indicating this as a significant cause of continued warming of the planet. It has been suggested that if these conditions in some way lead to enhanced DMSP production by marine algae, then this compound, via the sulphate aerosols that result from its breakdown, might act t...

Microalgal predation is one of the imminent threats for mass algae cultivation in open ponds. Invasion of predators results in total clearance of algal biomass within 24–48 h. Detection of contamination in microalgal cultures using online spectroscopy has attracted considerable interest among researchers. Currently reported spectral markers such as...

Environmental change and biodiversity loss are but two of the complex challenges facing conservation practitioners and policy makers. Relevant and robust scientific knowledge is critical for providing decision-makers with the actionable evidence needed to inform conservation decisions. In the Anthropocene, science that leads to meaningful improveme...

Algal metabolism concerns the biochemical and transport processes by which algae take up nutrients and convert them into the materials needed for growth, reproduction and defence of the organisms. Many of the metabolic processes that occur in algae are common to those found in other living organisms. This commonality is described, but emphasis is g...

The carbonate chemistry in coastal waters is more variable compared with that of open oceans, both in magnitude and time scale of its fluctuations. However, knowledge of the responses of coastal phytoplankton to dynamic changes in pH/pCO2 has been scarcely documented. Hence, we investigated the physiological performance of a coastal isolate of the...

The impacts of micro-and nanoplastics (MNPs) on aquatic animals have been intensively studied; however, the extent and magnitude of potential effects of MNPs on aquatic primary producers are poorly understood. In this study, we quantitatively analyzed the published literature to examine the impacts of MNPs on growth, photo-synthesis, pigments, and...

Macro‐nutrient limitation and increased solar exposure coincide with ocean warming‐enhanced stratification, with consequences for phytoplankton within the upper mixing layer. In this study, we grew a diatom, Thalassiosira punctigera, under nitrogen limited and replete conditions for more than 14 generations and investigated both the biochemical com...

While CO2 is the external inorganic carbon (Ci) form used for photosynthesis in terrestrial plants, the higher concentration of bicarbonate (HCO3⁻) in most water bodies renders this ionic Ci form the preferred external Ci source for most cyanobacteria, microalgae, and submerged macrophytes. The equilibrium concentrations of these two Ci forms depen...

Photosynthetic rates can be measured in several different ways. Classically, phytoplankton productivity has been measured by uptake rates of ¹⁴C-labelled inorganic carbon (Ci, i.e. CO2 and HCO3⁻), which is a sensitive measure even for sparse phytoplankton assemblages. For macrophytes, gas exchange of CO2 or O2 have been used as preferred methods of...

Chlorophyll fluorometers are constructed such that the immediate outcomes of the measurements provide information on quantum yields (Y) of electrons passing through photosystem II (PSII). If the photosynthetically active radiation (PAR) absorbed by PSII (PARa) is known, then photosynthetic rates can be calculated as electron transport rates (ETR)....

This book presents methods for investigating the effects of aquatic environmental changes on organisms and the mechanisms involved. It focuses mainly on photosynthetic organisms, but also provides methods for virus, zooplankton and other animal studies. Also including a comprehensive overview of the current methods in the fields of aquatic physiolo...

Cell size influences the rate at which phytoplankton assimilate dissolved inorganic carbon (DIC), but it is unclear whether volume‐specific carbon uptake should be greater in smaller or larger cells. On the one hand, Fick’s Law predicts smaller cells to have a superior diffusive CO2 supply. On the other, larger cells may have greater scope to inves...

Microalgae are major primary producers in aquatic environments, and many synthesize an array of industrially important biomolecules such as pigments, lipids and proteins. As a result, there is considerable interest in and effort into growing algae for industrial purposes. An economical method to produce a large amount of biomass is the use of the o...

Contaminant invasion is one of the risks associated with microalgal cultivation in open raceway ponds, and the presence of zooplankton predators often results in a pond culture crash. For effective pond management, an early grazer-detection tool is needed to implement timely interventions. Microalgae and their predators co-exist in the pelagic food...

Consumption of microalgae, as prey, by predatory zooplankton is a major ecological process in aquatic environments. The presence of predators in large-scale cultivation, such as in open ponds, results in a devastating loss of microalgal biomass, often referred to as a "pond crash." Reported biomass losses of 20-30% due to predator invasion in open...

Rising atmospheric CO2 concentrations are predicted to have a significant impact on global phytoplankton populations. Of particular interest in freshwater systems are those species that produce toxins or impact water quality, though evidence for how these species, and many others, will respond is limited. This study investigated the effects of elev...

The commercially important red macroalga Pyropia (formerly Porphyra) yezoensis is, in its natural intertidal environment, subjected to high levels of both photosynthetically active and ultraviolet radiation (PAR and UVR, respectively). In the present work, we investigated the effects of a plausibly increased global CO 2 concentration on quantum yie...

While seawater acidification induced by elevated CO2 is known to impact coccolithophores, the effects in combination with decreased salinity caused by sea ice melting and/or hydrological events have not been documented. Here we show the combined effects of seawater acidification and reduced salinity on growth, photosynthesis and calcification of Em...

The skin is the first line of defense against pathogen and other environmental pollutant. The body is constantly exposed to reactive oxygen species (ROS) that stimulates inflammatory process in the skin. Many studies have linked ROS to various inflammatory skin diseases. Patients with skin diseases face various challenges with inefficient and inapp...

Microalgae can tolerate a wide range of environmental conditions and have been exploited for their lipid and carbohydrate accumulating properties. The utility of this process could be further enhanced through understanding the critical gene regulatory networks that govern the acclimatization process. Advancements in systems biology and sequencing t...

Inorganic carbon assimilation in algae depends ultimately on the activity of ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco) and the Calvin-Benson-Bassham Cycle (Photosynthetic Carbon Reduction Cycle; PCRC). The kinetic characteristics of the different forms of Rubisco found in algae and cyanobacteria are such that under present day level...

Oxygen uptake in illuminated photosynthetic algae can be measured using ¹⁸O2 or (with some reservations) photosystem II electron flux measured by fluorescence corrected for electron flux to sinks other than O2. Water-water cycles, involve photosystem II removing electrons from water to produce O2. Water-water cycles involving photosystem I as well...

Ultraviolet (UV) filters are widely used in sunscreen and personal care products due to their ability to give protection to our skin from UV radiation. Oxybenzone, commonly known as benzophenone-3, is one type of UV filter found as the active ingredient in many pharmaceutical products. Although oxybenzone has been extensively studied as an environm...

Motility plays a critical role in algal survival and reproduction, with implications for aquatic ecosystem stability. However, the effect of elevated CO2 on marine, brackish and freshwater algal motility is unclear. Here we show, using laboratory microscale and field mesoscale experiments, that three typical phytoplankton species had decreased moti...

Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) and the Calvin cycle are the dominant features of inorganic carbon assimilation in all cyanobacteria and microalgae. Rubisco carboxylase shows a relatively low affinity for CO2 and also has an oxygenase activity. These features can lead to inefficiencies in carbon assimilation, involving the...

Generation of ion electrochemical potential differences by primary active transport can involve energy inputs from light, from exergonic redox reactions and from exergonic ATP hydrolysis. These electrochemical potential differences are important for homoeostasis, for signalling, and for energizing nutrient influx. The three main ions involved are H...

Applying physiological tools, knowledge and concepts to understand conservation problems (i.e. conservation physiology) has become commonplace and confers an ability to understand mechanistic processes, develop predictive models and identify cause-and-effect relationships. Conservation physiology is making contributions to conservation solutions; t...

Despite the increased interest in exploring the potential of algal biomass production for food stock and renewable energy, very little work has been done in developing reliable screening protocols to enable the identification of species that are best suited to mass cultivation outdoors. Nannochloropsis is an algal genus identified as a potential so...

Diatoms have relatively high biomass in mid‐ to high‐latitude oceans, which is also the most sensitive region to climate change. Photoautotrophs are thus predicted to become exposed to both higher temperatures and increased solar irradiance. In this study we examined the consequences of such changes for the growth and photo‐physiology of two diatom...

Salinity is one of the significant factors that affect growth and cellular metabolism, including photosynthesis and lipid accumulation, in microalgae and higher plants. Microchloropsis gaditana CCMP526 can acclimatize to different salinity levels by accumulating compatible solutes, carbohydrates, and lipids as an energy storage molecule. We used pr...

Algae have the potential to capture carbon dioxide (CO2) and nitric oxide (NO) from flue gases. However, the effects of high concentrations of these gases on the photophysiology of algae are poorly understood. To that end, we used the techniques of chlorophyll fluorescence to study the effect of industrially relevant levels of CO2 and NO on the pho...

Rising global temperatures have been suggested to favour cyanobacteria over eukaryotic algae, but UV‐B fluxes are also predicted to remain high and may interact with temperature to affect algal growth. To understand the interactive effects of temperature and UV‐B radiation, cultures of Microcystis aeruginosa and Anabaena circinalis were grown at ei...

Ultraviolet (UV) filters are widely used in sunscreen and personal care products due to their ability to give protection to our skin from UV radiation. Oxybenzone, commonly known as benzophenone-3, is one type of UV filter found as the active ingredient in many pharmaceutical products. Although oxybenzone has been extensively studied as an environm...