Response of estuarine fishes to elevated temperatures within temperate Australia: Implications of climate change on fish growth and foraging performance

2021 ◽  
Vol 544 ◽  
pp. 151626
Author(s):  
Casey O'Connor ◽  
David J. Booth
Keyword(s):  
Climate Change ◽  
Elevated Temperatures ◽  
Fish Growth ◽  
Estuarine Fishes ◽  
Foraging Performance

scholarly journals Forage quality declines with rising temperatures, with implications for livestock production and methane emissions

2017 ◽  
Vol 14 (6) ◽  
pp. 1403-1417 ◽  
Author(s):  
Mark A. Lee ◽  
Aaron P. Davis ◽  
Mizeck G. G. Chagunda ◽  
Pete Manning
Keyword(s):  
Climate Change ◽  
Methane Production ◽  
Nutritive Value ◽  
Elevated Temperatures ◽  
Environmental Changes ◽  
Forage Quality ◽  
Livestock Farming ◽  
Forage Plants ◽  
Model Average ◽  
Enteric Methane

Abstract. Livestock numbers are increasing to supply the growing demand for meat-rich diets. The sustainability of this trend has been questioned, and future environmental changes, such as climate change, may cause some regions to become less suitable for livestock. Livestock and wild herbivores are strongly dependent on the nutritional chemistry of forage plants. Nutrition is positively linked to weight gains, milk production and reproductive success, and nutrition is also a key determinant of enteric methane production. In this meta-analysis, we assessed the effects of growing conditions on forage quality by compiling published measurements of grass nutritive value and combining these data with climatic, edaphic and management information. We found that forage nutritive value was reduced at higher temperatures and increased by nitrogen fertiliser addition, likely driven by a combination of changes to species identity and changes to physiology and phenology. These relationships were combined with multiple published empirical models to estimate forage- and temperature-driven changes to cattle enteric methane production. This suggested a previously undescribed positive climate change feedback, where elevated temperatures reduce grass nutritive value and correspondingly may increase methane production by 0.9 % with a 1 °C temperature rise and 4.5 % with a 5 °C rise (model average), thus creating an additional climate forcing effect. Future methane production increases are expected to be largest in parts of North America, central and eastern Europe and Asia, with the geographical extent of hotspots increasing under a high emissions scenario. These estimates require refinement and a greater knowledge of the abundance, size, feeding regime and location of cattle, and the representation of heat stress should be included in future modelling work. However, our results indicate that the cultivation of more nutritious forage plants and reduced livestock farming in warming regions may reduce this additional source of pastoral greenhouse gas emissions.

scholarly journals Resilience to temperature and pH changes in a future climate change scenario in six strains of the polar diatom <i>Fragilariopsis cylindrus</i>

2015 ◽  
Vol 12 (14) ◽  
pp. 4235-4244 ◽  
Author(s):  
M. Pančić ◽  
P. J. Hansen ◽  
A. Tammilehto ◽  
N. Lundholm
Keyword(s):  
Climate Change ◽  
Growth Rates ◽  
Significant Interaction ◽  
Elevated Temperatures ◽  
Future Climate Change ◽  
Change Scenario ◽  
Ph Tolerance ◽  
Increased Temperature ◽  
Fragilariopsis Cylindrus ◽  
Negative Effect

Abstract. The effects of ocean acidification and increased temperature on physiology of six strains of the polar diatom Fragilariopsis cylindrus from Greenland were investigated. Experiments were performed under manipulated pH levels (8.0, 7.7, 7.4, and 7.1) and different temperatures (1, 5, and 8 °C) to simulate changes from present to plausible future levels. Each of the 12 scenarios was run for 7 days, and a significant interaction between temperature and pH on growth was detected. By combining increased temperature and acidification, the two factors counterbalanced each other, and therefore no effect on the growth rates was found. However, the growth rates increased with elevated temperatures by ~ 20–50 % depending on the strain. In addition, a general negative effect of increasing acidification on growth was observed. At pH 7.7 and 7.4, the growth response varied considerably among strains. However, a more uniform response was detected at pH 7.1 with most of the strains exhibiting reduced growth rates by 20–37 % compared to pH 8.0. It should be emphasized that a significant interaction between temperature and pH was found, meaning that the combination of the two parameters affected growth differently than when considering one at a time. Based on these results, we anticipate that the polar diatom F. cylindrus will be unaffected by changes in temperature and pH within the range expected by the end of the century. In each simulated scenario, the variation in growth rates among the strains was larger than the variation observed due to the whole range of changes in either pH or temperature. Climate change may therefore not affect the species as such, but may lead to changes in the population structure of the species, with the strains exhibiting high phenotypic plasticity, in terms of temperature and pH tolerance towards future conditions, dominating the population.

scholarly journals Lipidome analysis of Symbiodiniaceae reveals possible mechanisms of heat stress tolerance in reef coral symbionts

Coral Reefs ◽  
2019 ◽  
Vol 38 (6) ◽  
pp. 1241-1253 ◽  
Author(s):  
S. Rosset ◽  
G. Koster ◽  
J. Brandsma ◽  
A. N. Hunt ◽  
A. D. Postle ◽  
...  
Keyword(s):  
Climate Change ◽  
Heat Stress ◽  
Heat Tolerance ◽  
Lipid Composition ◽  
Elevated Temperatures ◽  
Reef Coral ◽  
Membrane Lipid ◽  
Steady Increase ◽  
Heat Stress Response ◽  
Photosynthetic Organisms

Abstract Climate change-induced global warming threatens the survival of key ecosystems including shallow water coral reefs. Elevated temperatures can disrupt the normal physiological functioning of photosynthetic organisms by altering the fluidity and permeability of chloroplast membranes that is defined and regulated by their lipid composition. Since the habitat-forming reef corals rely on the obligatory symbiosis with dinoflagellates of the family Symbiodiniaceae, their heat stress response can be expected to be strongly influenced by the symbiont's lipid metabolism. However, in contrast to the steady increase in the knowledge of the functioning of coral symbionts at the genomic and transcriptomic level, the understanding of their membrane lipid composition and regulation in response to temperature stress is lagging behind. We have utilised mass spectrometry-based lipidomic analyses to identify the key polar lipids that form the biological membranes of reef coral symbionts, comparing the thermotolerant species Durusdinium trenchii with the thermosensitive taxon Cladocopium C3, both hosted by Acropora valida. Our results indicate that the superior thermotolerance D. trenchii inside the host corals could be achieved through (1) the amount and saturation of sulfoquinovosyldiacylglycerols, in particular through putative photosystem II interactions, (2) the increased digalactosyldiacylglycerol to monogalactosyldiacylglycerol ratio with the potential to stabilise thylakoid membranes and integrated proteins, and (3) the chaperone-like function of lyso-lipids. Thereby, our study provides novel insights into the heat tolerance of coral symbionts, contributing to the understanding of the potential of coral reef ecosystems to respond and adjust to heat stress events that are becoming more frequent due to climate change. Finally, our identification of multiple mechanisms of heat tolerance in Symbiodiniaceae furthers the knowledge of the general stress physiology of photosynthetic organisms.

scholarly journals Effects of global climate change on chlorophyll-a concentrations in a tropical aquatic system during a cyanobacterial bloom: a microcosm study

2017 ◽  
Vol 12 (3) ◽  
pp. 390 ◽  
Author(s):  
Meirielle Euripa Pádua de Moura ◽  
Lorraine Dos Santos Rocha ◽  
João Carlos Nabout
Keyword(s):  
Climate Change ◽  
Chlorophyll A ◽  
Elevated Temperatures ◽  
Cyanobacterial Bloom ◽  
Aquatic Environments ◽  
Precipitation Pattern ◽  
Chl A ◽  
Extreme Precipitation Events ◽  
Rainfall Frequency ◽  
The Impact

Recent studies have investigated the impact of climate change on aquatic environments, and Chlorophyll-a (Chl-a) concentration is a quick and reliable variable for monitoring such changes. This study evaluated the impact of rainfall frequency as a diluting agent and the effect of increased temperature on Chl-a concentrations in eutrophic environments during a bloom of cyanobacteria. This was based on the hypothesis that the concentration of Chl-a will be higher in treatments in which the rainfall frequency is not homogeneous and that warmer temperatures predicted due to climate change should favor higher concentrations of Chl-a. The experiment was designed to investigate three factors: temperature, precipitation and time. Temperature was tested with two treatment levels (22°C and the future temperature of 25°C). Precipitation was tested with four treatments (no precipitation, a homogeneous precipitation pattern, and two types of concentrated precipitation patterns). Experiments were run for 15 days, and Chl-a concentration was measured every five days in each of the temperature and precipitation treatments. The water used in the microcosms was collected from a eutrophic lake located in Central Brazil during a bloom of filamentous cyanobacteria (Geilterinema amphibium). Chl-a levels were high in all treatments. The higher temperature treatment showed increased Chl-a concentration (F=10.343; P=0.002); however, the extreme precipitation events did not significantly influence Chl-a concentrations (F=1.198; P=0.326). Therefore, the study demonstrates that future climatic conditions (projected to 2100), such as elevated temperatures, may affect the primary productivity of aquatic environments in tropical aquatic systems.

scholarly journals The impacts of climate change on fish growth: A summary of conducted studies and current knowledge

2021 ◽  
Vol 121 ◽  
pp. 106976
Author(s):  
Minrui Huang ◽  
Liuyong Ding ◽  
Jun Wang ◽  
Chengzhi Ding ◽  
Juan Tao
Keyword(s):  
Climate Change ◽  
Current Knowledge ◽  
Fish Growth ◽  
Impacts Of Climate Change

scholarly journals Effects of climate change on fish reproduction and early life history stages

2011 ◽  
Vol 62 (9) ◽  
pp. 1015 ◽  
Author(s):  
Ned W. Pankhurst ◽  
Philip L. Munday
Keyword(s):  
Climate Change ◽  
Elevated Temperatures ◽  
Endocrine System ◽  
Developmental Rate ◽  
Early Life History ◽  
Egg Survival ◽  
Life History Stages ◽  
Larval Fishes ◽  
Larval Behaviour ◽  
Temperature Ranges

Seasonal change in temperature has a profound effect on reproduction in fish. Increasing temperatures cue reproductive development in spring-spawning species, and falling temperatures stimulate reproduction in autumn-spawners. Elevated temperatures truncate spring spawning, and delay autumn spawning. Temperature increases will affect reproduction, but the nature of these effects will depend on the period and amplitude of the increase and range from phase-shifting of spawning to complete inhibition of reproduction. This latter effect will be most marked in species that are constrained in their capacity to shift geographic range. Studies from a range of taxa, habitats and temperature ranges all show inhibitory effects of elevated temperature albeit about different environmental set points. The effects are generated through the endocrine system, particularly through the inhibition of ovarian oestrogen production. Larval fishes are usually more sensitive than adults to environmental fluctuations, and might be especially vulnerable to climate change. In addition to direct effects on embryonic duration and egg survival, temperature also influences size at hatching, developmental rate, pelagic larval duration and survival. A companion effect of marine climate change is ocean acidification, which may pose a significant threat through its capacity to alter larval behaviour and impair sensory capabilities. This in turn impacts on population replenishment and connectivity patterns of marine fishes.

Drought and water management in the German agricultural sector - a participatory system dynamics approach

2020 ◽  
Author(s):  
Rodrigo Valencia ◽  
Sabine Egerer ◽  
María Máñez
Keyword(s):  
Climate Change ◽  
Water Management ◽  
Water Balance ◽  
System Dynamics ◽  
Model Building ◽  
Elevated Temperatures ◽  
Agricultural System ◽  
Group Model ◽  
Wide Range ◽  
The Impact

&lt;p&gt;Higher temperatures and changes in precipitation patterns caused by climate change may potentially affect water availability for agriculture and increase the risk of crop loss in Northeast Lower Saxony (NELS), Germany. The drought of 2018 showed that an intensification of irrigation might be a temporary solution. However, a long-term increase in water extraction, especially during drought periods, is not a sustainable solution. To assess possible water management solutions, we implement a participatory system dynamics approach, namely Group Model Building, to develop a qualitative system dynamics model (QSDM) describing the agricultural system and its relation to water resources in NELS.&lt;/p&gt;&lt;p&gt;The development of the QSDM seeks to understand the complexity of the interactions between agriculture and hydrological systems, recognize the stakeholders&amp;#8217; needs and identify risks and weaknesses of both systems. By understanding this, we expect to reinforce the adaptation process, reduce conflict and be able to suggest tailored solutions and adaptation measures. The QSDM incorporates a wide range of perceptions, as twenty stakeholders ranging from farmers, government agencies, environmental protection organizations and local water authorities were involved in the QSDM development. Their perceptions were recorded in the QSDM through individual interviews and a group workshop.&lt;/p&gt;&lt;p&gt;Through the QSDM, we identified and mapped the structure and connections between agriculture and the water balance. It was also possible to identify the strongest feedback loops governing both sectors as well as their influence on the current situation. The loops represent behaviors and structures, which might become unmanageable under climate change conditions. The causal loops include the different uses for the available water of the region, the impact of irrigation, the significance of crop selection and the importance of sustainable soil management.&lt;/p&gt;&lt;p&gt;By analyzing the system this way, we confirmed that climate change poses a risk to the region as elevated temperatures could increase the crop water demand and increase the need for irrigation. In the same way, changes in the rain patterns could affect the water balance of the region. The agricultural system has, however, potential to adapt by implementing new water management strategies such as restructuring water rights, water storage and reuse and conjunctive water use. Other measures include increasing the irrigation efficiency, changing crops and enhancing the soil quality, among others.&lt;/p&gt;

scholarly journals Vascular plants affect properties and decomposition of moss-dominated peat, particularly at elevated temperatures

2020 ◽  
Vol 17 (19) ◽  
pp. 4797-4813
Author(s):  
Lilli Zeh ◽  
Marie Theresa Igel ◽  
Judith Schellekens ◽  
Juul Limpens ◽  
Luca Bragazza ◽  
...  
Keyword(s):  
Climate Change ◽  
Vascular Plants ◽  
Elevated Temperatures ◽  
Vascular Plant ◽  
Chemical Properties ◽  
Pyrolysis Product ◽  
Calluna Vulgaris ◽  
Mean Annual Temperature ◽  
Multiple Parameters ◽  
Vegetation Shift

Abstract. Peatlands, storing significant amounts of carbon, are extremely vulnerable to climate change. The effects of climate change are projected to lead to a vegetation shift from Sphagnum mosses to sedges and shrubs. Impacts on the present moss-dominated peat remain largely unknown. In this study, we used a multiproxy approach to investigate the influence of contrasting vascular plant types (sedges, shrubs) on peat chemistry and decomposition. Peat cores of 20 cm depth and plant material (Sphagnum spp., Calluna vulgaris and Eriophorum vaginatum) from two ombrotrophic peatlands in the Italian Alps with a mean annual temperature difference of 1.4 ∘C were analyzed. Peat cores were taken under adjacent shrub and sedge plants growing at the same height above the water table. We used carbon, nitrogen and their stable isotopes to assess general patterns in the degree of decomposition across sampling locations and depths. In addition, analytical pyrolysis was applied to disentangle effects of vascular plants (sedge, shrub) on chemical properties and decomposition of the moss-dominated peat. Pyrolysis data confirmed that Sphagnum moss dominated the present peat irrespective of depth. Nevertheless, vascular plants contributed to peat properties as revealed by, e.g., pyrolysis products of lignin. The degree of peat decomposition increased with depth as shown by, e.g., decreasing amounts of the pyrolysis product of sphagnum acid and increasing δ13C with depth. Multiple parameters also revealed a higher degree of decomposition of Sphagnum-dominated peat collected under sedges than under shrubs, particularly at the high temperature site. Surprisingly, temperature effects on peat decomposition were less pronounced than those of sedges. Our results imply that vascular plants affect the decomposition of the existing peat formed by Sphagnum, particularly at elevated temperature. These results suggest that changes in plant functional types may have a stronger impact on the soil carbon feedback in a warmer world than hitherto assumed.

scholarly journals Thermal sensitivity and seasonal change in the gut microbiome of a desert ant, Cephalotes rohweri

2021 ◽  
Author(s):  
Marshall S McMunn ◽  
Asher I Hudson ◽  
Ash Zemenick ◽  
Monika Egerer ◽  
Stacy M Philpott ◽  
...  
Keyword(s):  
Climate Change ◽  
Elevated Temperatures ◽  
Variable Temperature ◽  
Thermal Sensitivity ◽  
Thermal Exposure ◽  
Seasonal Temperature ◽  
Microbiome Composition ◽  
Desert Ant ◽  
Temperature Regimes ◽  
Response To Temperature

Microorganisms within ectotherms must withstand the variable body temperatures of their hosts. Shifts in host body temperature resulting from climate change have the potential to shape ectotherm microbiome composition. Microbiome compositional changes occurring in response to temperature in nature have not been frequently examined, restricting our ability to predict microbe-mediated ectotherm responses to climate change. In a set of field-based observations, we characterized gut bacterial communities and thermal exposure across a population of desert arboreal ants (Cephalotes rohweri). In a paired growth chamber experiment, we exposed ant colonies to variable temperature regimes differing by 5 C for three months. We found that the abundance and composition of ant-associated bacteria were sensitive to elevated temperatures in both field and laboratory experiments. We observed a subset of taxa that responded similarly to temperature in the experimental and observational study, suggesting a role of seasonal temperature and local temperature differences amongst nests in shaping microbiomes within the ant population. Bacterial mutualists in the genus Cephalotococcus (Opitutales: Opitutaceae) were especially sensitive to change in temperature - decreasing in abundance in naturally warm summer nests and warm growth chambers. We also report the discovery of a member of the Candidate Phlya Radiation (Phylum: Gracilibacteria), a suspected epibiont, found in low abundance within the guts of this ant species.

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