Download or read book Interactive Effects of Temperature Nutrient Availability and Dissolved Organic Carbon Concentrations on the Response of Alpine Phytoplankton Population Growth to Ultraviolet Radiation written by Shaina A. Doyle and published by . This book was released on 2005 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Seasonal Variation in the Effects of Nutrient and Dissolved Organic Matter Concentrations on the Response of Phytoplankton Community Structure to Ultraviolet Radiation written by Caren E. Scott and published by . This book was released on 2006 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aquatic Ecosystems in a Changing Climate written by Donat-P Häder and published by CRC Press. This book was released on 2018-11-16 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt: Global climate change affects productivity and species composition of freshwater and marine aquatic ecosystems by raising temperatures, ocean acidification, excessive solar UV and visible radiation. Effects on bacterioplankton and viruses, phytoplankton and macroalgae have farreaching consequences for primary consumers such as zooplankton, invertebrates and vertebrates, as well as on human consumption of fish, crustaceans and mollusks. It has affected the habitation of the Arctic and Antarctic oceans the most so far. Increasing pollution from terrestrial runoff, industrial, municipal and household wastes as well as marine transportation and plastic debris also affect aquatic ecosystems.
Download or read book Sensitivity of Phytoplankton to Climate Change written by Miriam Seifert and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine phytoplankton constitutes about half of the primary production on Earth. It forms the base of the marine food web and is a pivotal player in the marine biological carbon pump. The primary environmental drivers that control phytoplankton growth are temperature, nutrient availability, light, and the concentration of inorganic carbon species. Ongoing climate change modifies these drivers, leading to a warming, high-CO2 ocean with altered nutrient availabilities and light regimes. Changes in phytoplankton productivity and community composition resulting from these newly emerging environmental states in the ocean have important implications for the marine ecosystem and carbon cycling. Biogeochemical ocean models are used to investigate how marine primary production may be affected by future climate change under different emission scenarios. Phytoplankton growth rates in models are typically determined by functions describing growth dependencies on temperature, light, and nutrients. However, a large body of laboratory studies on phytoplankton responses to environmental drivers reveals two points that are usually not considered in current biogeochemical models. Firstly, phytoplankton growth can be considerably modified by the state of the carbonate system. Changes in inorganic carbon species concentrations can be either growth-enhancing (CO2(aq) and bicarbonate are substrates for photosynthesis), or growth-dampening (increasing CO2(aq) levels lead to a shift in the carbonate equilibria and result in a pH decrease, a process which is called ocean acidification). Functions describing this growth dependence of phytoplankton on the carbonate system have not been implemented in large-scale ocean biogeochemical models so far. Secondly, growth responses towards one driver can be modified if the level of another driver is changing. Functions including these so-called interactive driver effects partly exist in models (e.g. the response to varying light levels may depend on the nutrient limitation term). However, the large number of laboratory studies on multiple driver effects has never been used to constrain driver interactions in large-scale ocean biogeochemical models. This holds especially true for the findings of growth responses to driver interactions that include ocean acidification, which make up the largest share of laboratory experiments. This thesis aims to investigate sensitivities of marine phytoplankton to changing CO2(aq) levels as well as to interactive effects between CO2 and other environmental drivers. A comprehensive and reproducible literature search in combination with a statistical analysis (Publication I) reveals that increasing CO2(aq) levels robustly dampen the growth-increasing effects of warming and improving light conditions. In addition, the results show that the calcifying phytoplankton group of coccolithophores experiences the strongest negative effects by ocean acidification compared to other phytoplankton groups. A second study (Publication II) examines the effects of mechanistically described carbonate system dependencies on primary production and community composition in a model. To this end, carbonate system dependencies of phytoplankton growth and and coccolithophore calcification are implemented into the global biogeochemical ocean model REcoM. The study shows that responses to ocean acidification cascade on growth responses to other drivers, which partly balance or counteract the direct impact of the carbonate system on growth rates. In addition, warming is identified as the main driver of the observed recent increase of coccolithophore biomass in the North Atlantic. A final study (Publication III) investigates the interactive effects between CO2 and temperature as well as between CO2 and light on phytoplankton biomass and community composition in a high emission scenario. For the parametrization in REcoM, growth responses to interacting drivers as synthesized in Publication I are used. The decrease of global future phytoplankton biomass and net community production by the end of the century is similar in simulations with and without driver interactions (-6% and -8%, respectively). However, phytoplankton responses to future climate conditions are considerably modified on a regional scale and the share of individual phytoplankton groups in the community changes both globally and regionally when accounting for multiple driver effects. Globally, diatoms and coccolithophores are impacted more and small phytoplankton less severely by future oceanic conditions when accounting for driver interactions. Future projections of the Southern Ocean phytoplankton community are modified most dramatically with the new interactive growth formulation, as diatoms and coccolithophores become less and small phytoplankton more abundant, while it is the other way round in simulations without driver interactions. The thesis highlights 1) that the carbonate system is a critical growth-modifying driver for phytoplankton in a high-CO2 ocean, which can furthermore modify growth responses to other drivers substantially, and 2) that driver interactions have considerable effects on climate-change induced alterations in the phytoplankton community as well as on regional biomass changes in a future ocean.
Download or read book The Ecology of Phytoplankton written by C. S. Reynolds and published by Cambridge University Press. This book was released on 2006-05-04 with total page 437 pages. Available in PDF, EPUB and Kindle. Book excerpt: This important new book by Colin Reynolds covers the adaptations, physiology and population dynamics of phytoplankton communities. It provides basic information on composition, morphology and physiology of the main phyletic groups represented in marine and freshwater systems and in addition reviews recent advances in community ecology.
Download or read book Direct and interactive effects of allochthonous dissolved organic matter inorganic nutrients and ultraviolet radiation on an alpine littoral food web written by R.D. VINEBROOKE and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Interaction of Ultraviolet Radiation Dissolved Organic Carbon and Primary Production by Laurentian Great Lake Phytoplankton Communities written by Daniel T. Hamilton and published by . This book was released on 2011 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: Man-made chemicals are continuing to erode the ozone layer, and recovery of the ozone layer is slow. Therefore aquatic ecosystems are continuing to receive elevated ultraviolet radiation (UVR). The aim of this work was to investigate and quantify the impact of ultraviolet light on photosynthesis at various near-shore Great Lakes sites (Hamilton Harbour, Lake Ontario, Bay of Quinte, Woods Bay, Georgian Bay) using both oxygen metabolism and carbon assimilation. Enhanced UVR suppressed primary production at all stations when compared to incubations with photosynthetically active radiation (PAR) only. The average decline in net O2 production was greater than 90% and sometime exceeded 100%; that is, enhanced UVR often produced net consumption of oxygen. Carbon was always assimilated with UVR+PAR exposure, although C- assimilation declined on average between 40 and 60% relative to PAR only, so there must have been some photosynthetic activity taking place as well as enhanced oxygen consumption. The oxygen consumption appears to be biotic, as tests for abiotic oxygen consumption failed to demonstrate any O2 loss. Dark respiration after 4-h light treatments with PAR or PAR+UVR was sometimes different, but not in a consistent way even at the same site. For example, at Hamilton Harbour on two occasions respiration after the PAR+ UVR exposure exceeded the PAR only treatments, while on the remaining dates dark respiration after the PAR- only treatments exceeded the PAR+UV treatment. While there is some evidence of enhanced dark respiration as a result of exposure during incubation in enhanced ultraviolet radiation, it appears that the decline in net photosynthesis is caused mainly be the decline in gross photosynthesis rather than an increase in respiration. Carbon assimilation was suppressed under enhanced ultraviolet radiation, and the degree of suppression was negatively related to the 14-day cumulative average of ultraviolet radiation (at 295 nm) prior to the experiment. I interpret this as evidence that phytoplankton to adapt to UVR exposure. Neither chlorophyll nor DOC appeared to be important factors. Bacterial productivity also responded to the PAR + UVR irradiation compared to the PAR alone incubations although the response appeared to vary with season. Experimental PAR + UVR incubations carried out during the mid season appeared to have higher production during the 12 h post-treatment dark incubation compared to incubations under PAR, while those from later in the season tended to respond with suppressed productivity in the PAR + UVR incubations compared to the PAR alone.
Download or read book The Effect of Rising Carbon Dioxide on Communities of Freshwater Phytoplankton written by Egor Katkov and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Human activities, such as CO2 emissions are altering aquatic ecosystems in ways that are not fully understood. Because phytoplankton are essential organisms, forming the base of pelagic aquatic food webs, I focus on this group to help us understand how lake ecosystems respond to anthropogenic change. Specifically, I focus on the response of total phytoplankton biomass and community composition to increasing pCO2 in concert with (1) nutrient enrichment, (2) increasing temperatures, and (3) organismal evolution.In the first chapter, I investigated whether CO2 can act as a co-limiting resource that can promote phytoplankton growth and alter community composition across different times of the year. I conducted experiments using mesocosms suspended in a temperate mesotrophic lake, and designed them to evaluate the interactive effects of nitrogen, phosphorus, and CO2 enrichment in the months of July, August, October, April and June. I found that, in some seasons, CO2 acted as a co-limiting factor with phosphorus when nitrogen was also added. The phytoplankton community was affected by all three resources in diverse ways at different times of the year. I concluded that CO2 can affect the community composition and be a co-limiting factor for freshwater phytoplankton communities, especially when other resources are abundant, as is typical in eutrophic lakes.In chapter two, I investigated the interactive effect of CO2 and temperature on phytoplankton and zooplankton communities, two highly inter-related factors in the context of climate change. In the same lake as Chapter 1, I ran a single mesocom experiment in late Fall over four weeks. I did not detect an interactive effect between CO2 and temperature, although both factors had independent and additive effects on the phytoplankton community, and temperature altered zooplankton community composition. Additionally, CO2 altered the stoichiometry of the seston, which has been shown in other studies to affect zooplankton food quality. I concluded that, although no evidence for interactive effects was found, CO2 and temperature can have independent and additive effects across and multiple trophic levels in freshwater ecosystems.The third chapter deals with the evolutionary potential of phytoplankton species responding to changing atmospheric CO2 concentrations. I developed an eco-evolutionary model where phytoplankton growth depends on the influx of atmospheric CO2 and carbon uptake kinetics can evolve to trade off maximum carbon flux for affinity. At equilibrium, I found that populations adapted by optimizing carbon uptake to environmental conditions, which, in modelled monocultures, allowed populations to reach higher biomass, and in multi-species communities, allowed certain species to gain an unexpected advantage over others. The biomass increases depended on the species-specific parameters and concentrations of atmospheric CO2 and initial HCO3. I concluded that evolution in the context of changing pCO2 can affect community composition and generate greater biomass increases than expected from CO2 co-limitation alone.In sum, I found that biomass and composition of freshwater phytoplankton communities can be affected by increases in pCO2, by co-limitation, potentially in concert with factors like temperature, and evolution. One key observation and conclusion across all chapters of this thesis is the ecological and evolutionary effects of CO2 are generally small (compared to eutrophication) and may be involved in complex interactions. Such small effect sizes may seem to make it unnecessary to study the effects of enriched CO2. However, the fact that pCO2 concentrations are increasing worldwide, that even a small but large-scale effect can be significant, and that freshwaters are fragile but essential ecosystems, at the mercy of countless potentially interacting human activities, emphasizes the importance of understanding the impact of high pCO2 on freshwater communities"--
Download or read book Ecology Abstracts written by and published by . This book was released on 1996 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coverage: 1982- current; updated: monthly. This database covers current ecology research across a wide range of disciplines, reflecting recent advances in light of growing evidence regarding global environmental change and destruction. Major ares of subject coverage include: Algae/lichens, Animals, Annelids, Aquatic ecosystems, Arachnids, Arid zones, Birds, Brackish water, Bryophytes/pteridophytes, Coastal ecosystems, Conifers, Conservation, Control, Crustaceans, Ecosyst em studies, Fungi, Grasses, Grasslands, High altitude environments, Human ecology, Insects, Legumes, Mammals, Management, Microorganisms, Molluscs, Nematodes, Paleo-ecology, Plants, Pollution studies, Reptiles, River basins, Soil, TAiga/tundra, Terrestrial ecosystems, Vertebrates, Wetlands, Woodlands.
Download or read book Aquatic Organic Matter Fluorescence written by Paula G. Coble and published by Cambridge University Press. This book was released on 2014-07-14 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: A core text on principles, laboratory/field methodologies, and data interpretation for fluorescence applications in aquatic science, for advanced students and researchers.
Download or read book Interactive Effects of Temperature and Bisphenol A on Phytoplankton Growth Community Structure and Bioremediation Capacity written by Meredith Theus and published by . This book was released on 2021 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Practical Handbook of Seawater Analysis written by J. D. H. Strickland and published by . This book was released on 1977 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Climate Change Impacts on Stoichiometry Phytoplankton and Zooplankton in Alpine Lake Food Webs written by Raymond P. Weidman and published by . This book was released on 2013 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main hypothesis of this study was that warmer and drier conditions affect fishless alpine lakes by increasing (1) phosphorus (P)-availability, (2) P-limited autotrophs versus mixotrophic phytoflagellates, and (3) fast-growing P-limited cladocerans versus slower-growing nitrogen (N)-rich calanoid copepods. To test this hypothesis, I conducted (1) a spatial survey of 16 mountain lakes along 1016 m of elevation (summer water temperatures: 5-17°C) in Alberta; (2) a temporal survey of an alpine lake over 16 y (summer water temperatures: 3-14°C); and (3) a laboratory experiment using two alpine and montane plankton communities subjected to warming (10°C; 17°C) and increased dissolved organic carbon (DOC; +80%). In the lake survey, higher temperatures and decreased lake depth were inferred using structural equation modeling (SEM) to decrease dissolved N:P, which increased chlorophytes and cyanophytes relative to phytoflagellates. Warming suppressed large-bodied cladocerans (Daphnia middendorffiana) and calanoid copepods (Hesperodiaptomus arcticus) and increased small-bodied zooplankton taxa. Small copepods increased relative to small cladocerans; this decreased particulate C:P via increased P-recycling by copepods. In the temporal investigation, SEM revealed that decreased rain reduced flushing of dissolved P, which increased diatoms relative to phytoflagellates in Pipit Lake. Unlike the lake survey, more moderate warming increased D. middendorffiana, while H. arcticus increased with advanced ice-off. Thus, cladocerans increased relative to copepods, which increased particulate C:P via increased P-retention by zooplankton. In the experiment, warming and DOC additions together increased P-availability, which increased autotrophs and offset the negative direct effects of warming and DOC. Warming increased D. middendorffiana but suppressed H. arcticus. Particulate C:P increased with DOC additions and increased cladocerans relative to copepods. These findings partially supported my main hypothesis. Climate effects increased dissolved P-availability, thereby increasing autotrophs relative to phytoflagellates. Shorter-term warming (temporal survey and experiment) increased cladocerans relative to copepods, whereas longer-term warming (spatial survey) suppressed large-bodied zooplankton and increased small taxa. Particulate C:P varied with changes in cladocerans relative to copepods (via P-recycling) and increases in C-rich terrestrial inputs. Findings suggest climate change will increase primary productivity of alpine lakes over several decades by increasing P-availability, and decreasing grazing efficiency as copepods and smaller-bodied zooplankton supercede cladocerans.
Download or read book Arctic Antarctic and Alpine Research written by and published by . This book was released on 2004 with total page 670 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Real time Coastal Observing Systems for Marine Ecosystem Dynamics and Harmful Algal Blooms written by Babin, Marcel and published by UNESCO. This book was released on 2008-06-05 with total page 880 pages. Available in PDF, EPUB and Kindle. Book excerpt: The proliferation of harmful phytoplankton in marine ecosystems can cause massive fish kills, contaminate seafood with toxins, impact local and regional economies and dramatically affect ecological balance. Real-time observations are essential for effective short-term operational forecasting, but observation and modelling systems are still being developed. This volume provides guidance for developing real-time and near real-time sensing systems for observing and predicting plankton dynamics, including harmful algal blooms, in coastal waters. The underlying theory is explained and current trends in research and monitoring are discussed.Topics covered include: coastal ecosystems and dynamics of harmful algal blooms; theory and practical applications of in situ and remotely sensed optical detection of microalgal distributions and composition; theory and practical applications of in situ biological and chemical sensors for targeted species and toxin detection; integrated observing systems and platforms for detection; diagnostic and predictive modelling of ecosystems and harmful algal blooms, including data assimilation techniques; observational needs for the public and government; and future directions for research and operations.
Download or read book Environmental Chemistry of Lakes and Reservoirs written by Lawrence A. Baker and published by . This book was released on 1994 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: Developed from a symposium at the 201st National Meeting of the ACS in Atlanta, April 1991, this broad-ranging investigation, practical in orientation, is designed to meet the needs not only of chemists, but also environmental engineers and biologists, and scientists involved in practical aspects of water pollution, as well as those with a theoretical bent. It describes lake geochemistry, the cycling and distribution of major elements in aquatic systems, the behavior of trace metals in lakes, and organic contaminants. Theory, practical techniques, potential research, and policy implications are discussed. Annotation copyright by Book News, Inc., Portland, OR
Download or read book The Regional Impacts of Climate Change written by Intergovernmental Panel on Climate Change. Working Group II. and published by Cambridge University Press. This book was released on 1998 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cambridge, UK : Cambridge University Press, 1998.
