Diel Vertical and Horizontal Migration of Zooplankton Across a Gradient of Dissolved
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Pond and Lake Ecosystems a Pond Or Lake Ecosystem Includes Biotic
Pond and Lake Ecosystems A pond or lake ecosystem includes biotic (living) plants, animals and micro-organisms, as well as abiotic (nonliving) physical and chemical interactions. Pond and lake ecosystems are a prime example of lentic ecosystems. Lentic refers to stationary or relatively still water, from the Latin lentus, which means sluggish. A typical lake has distinct zones of biological communities linked to the physical structure of the lake. (Figure below) The littoral zone is the near shore area where sunlight penetrates all the way to the sediment and allows aquatic plants (macrophytes) to grow. Light levels of about 1% or less of surface values usually define this depth. The 1% light level also defines the euphotic zone of the lake, which is the layer from the surface down to the depth where light levels become too low for photosynthesizers. In most lakes, the sunlit euphotic zone occurs within the epilimnion. However, in unusually transparent lakes, photosynthesis may occur well below the thermocline into the perennially cold hypolimnion. For example, in western Lake Superior near Duluth, MN, summertime algal photosynthesis and growth can persist to depths of at least 25 meters, while the mixed layer, or epilimnion, only extends down to about 10 meters. Ultra-oligotrophic Lake Tahoe, CA/NV, is so transparent that algal growth historically extended to over 100 meters, though its mixed layer only extends to about 10 meters in summer. Unfortunately, inadequate management of the Lake Tahoe basin since about 1960 has led to a significant loss of transparency due to increased algal growth and increased sediment inputs from stream and shoreline erosion. -
Estimates of Hypolimnetic Oxygen Deficits in Ponds
Aquacullure and Fisheries Management 1989, 20, 167-172 Estimates of hypolimnetic oxygen deficits in ponds W. Y. B. CHANG Center for Great Lakes and Aquatic Sciences, University of Michigan, Ann Arbor, Michigan, USA Abstract. Shallow tropical integrated culture ponds in the Pearl River Delta. China, have been found to stratify almost daily, with high organic loadings and dense algal growth. The dissolved oxygen (DO) concentration is super-saturated in the epilimnion and is under 2 mg/l in the hypolimnion (>lm). The compensation depth corresponds to twice the Secchi disk depth ranging from 50 to 80cm. As a result, little or no net oxygen is produced in the hypolimnion (> 1 m). The low DO concentration in the hypolimnion causes organic materials, such as unused organic wastes and senescent algae cells, to be incompletely oxidized, since the rate of oxygen consumption by oxidable matter in water is dependent on the dissolved oxygen concentration in water. This material becomes the source of hypolimnetic oxygen deficits (HOD) which can drive whole pond DO to a dangerously low level, should sudden destratification occur. An improved estimate of hypolimnetic oxygen deficits is introduced in this article, and the advantages of this method are discussed. Introduction Oxygen is an important parameter in fish culture, and adequate levels of dissolved oxygen (DO) are essential for maintaining optimum fish growth. Inadequate dissolved oxygen and poor water quality are frequently found in ponds receiving organic wastes and can lead to many serious problems for fish culture in ponds. Problems of low dissolved oxygen are particularly prevalent in ponds during the night and early morning when there are high densities of fish and large additions of organic wastes and feeds (Schroeder 1974; Boyd 1982; Chang 1986). -
Elsevier First Proof
CLGY 00558 a0005 Trophic Structure E Preisser, University of Massachusetts at Amherst, Amherst, MA, USA ª 2007 Elsevier B.V. All rights reserved. Introduction Further Reading Control of Trophic Structure Energy transfer from producers to higher Factors Affecting Control of Trophic Structure trophic levels s0005 Introduction emphasizes the role(s) played by nutrient limitation and energetic inputs to producers and the subsequent effi- p0005 Trophic structure is defined as the partitioning of biomass ciency of energy transfer between trophic levels in between trophic levels (subsets of an ecological commu- determining the biomass accumulation at each trophic nity that gather energy and nutrients in similar ways, that level. The second category, top-down control, empha- is, producers, carnivores). The forces controlling biomass sizes the importance of predation in producing patterns accumulation at each trophic level have been a central of biomass accumulation that are often at odds with those concern of ecology dating from the early twentieth-cen- predicted byPROOF energy inputs alone. While recognizing the tury work of Elton and Lindeman. While interspecific differences between these two factors, it is also important interactions such as omnivory and intraguild predation to emphasize that both bottom-up and top-down factors can make it difficult to assign many organisms to a single represent extremes along a continuum of importance for trophic level, several broadly defined trophic levels are regulatory control. While ecologists debate the extent nonetheless clearly distinguishable. Primary producers, to which bottom-up versus top-down control influence autotrophic organisms (primarily plants and algae) that trophic structure in particular ecosystems, there is a broad convert light or chemical energy into biomass, make up consensus that both need to be considered when consid- the basal trophic level. -
DEEP SEA LEBANON RESULTS of the 2016 EXPEDITION EXPLORING SUBMARINE CANYONS Towards Deep-Sea Conservation in Lebanon Project
DEEP SEA LEBANON RESULTS OF THE 2016 EXPEDITION EXPLORING SUBMARINE CANYONS Towards Deep-Sea Conservation in Lebanon Project March 2018 DEEP SEA LEBANON RESULTS OF THE 2016 EXPEDITION EXPLORING SUBMARINE CANYONS Towards Deep-Sea Conservation in Lebanon Project Citation: Aguilar, R., García, S., Perry, A.L., Alvarez, H., Blanco, J., Bitar, G. 2018. 2016 Deep-sea Lebanon Expedition: Exploring Submarine Canyons. Oceana, Madrid. 94 p. DOI: 10.31230/osf.io/34cb9 Based on an official request from Lebanon’s Ministry of Environment back in 2013, Oceana has planned and carried out an expedition to survey Lebanese deep-sea canyons and escarpments. Cover: Cerianthus membranaceus © OCEANA All photos are © OCEANA Index 06 Introduction 11 Methods 16 Results 44 Areas 12 Rov surveys 16 Habitat types 44 Tarablus/Batroun 14 Infaunal surveys 16 Coralligenous habitat 44 Jounieh 14 Oceanographic and rhodolith/maërl 45 St. George beds measurements 46 Beirut 19 Sandy bottoms 15 Data analyses 46 Sayniq 15 Collaborations 20 Sandy-muddy bottoms 20 Rocky bottoms 22 Canyon heads 22 Bathyal muds 24 Species 27 Fishes 29 Crustaceans 30 Echinoderms 31 Cnidarians 36 Sponges 38 Molluscs 40 Bryozoans 40 Brachiopods 42 Tunicates 42 Annelids 42 Foraminifera 42 Algae | Deep sea Lebanon OCEANA 47 Human 50 Discussion and 68 Annex 1 85 Annex 2 impacts conclusions 68 Table A1. List of 85 Methodology for 47 Marine litter 51 Main expedition species identified assesing relative 49 Fisheries findings 84 Table A2. List conservation interest of 49 Other observations 52 Key community of threatened types and their species identified survey areas ecological importanc 84 Figure A1. -
Indirect Consequences of Hypolimnetic Hypoxia on Zooplankton Growth in a Large Eutrophic Lake
Vol. 16: 217–227, 2012 AQUATIC BIOLOGY Published September 5 doi: 10.3354/ab00442 Aquat Biol Indirect consequences of hypolimnetic hypoxia on zooplankton growth in a large eutrophic lake Daisuke Goto1,8,*, Kara Lindelof2,3, David L. Fanslow4, Stuart A. Ludsin4,5, Steven A. Pothoven4, James J. Roberts2,6, Henry A. Vanderploeg4, Alan E. Wilson2,7, Tomas O. Höök1,2 1Department of Forestry and Natural Resources, Purdue University, West Lafayette, Indiana 47907, USA 2Cooperative Institute for Limnology and Ecosystems Research, University of Michigan, Ann Arbor, Michigan 48108, USA 3Department of Environmental Sciences, University of Toledo, Toledo, Ohio 43606, USA 4Great Lakes Environmental Research Laboratory, National Oceanic and Atmospheric Administration, Ann Arbor, Michigan 48108, USA 5Aquatic Ecology Laboratory, Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, Ohio 43212, USA 6Colorado State University, Department of Fish, Wildlife and Conservation Biology, Fort Collins, Colorado 80523, USA 7Department of Fisheries and Allied Aquacultures, Auburn University, Auburn, Alabama 36849, USA 8School of Biological Sciences, University of Nebraska Lincoln, Lincoln, Nebraska 68588, USA ABSTRACT: Diel vertical migration (DVM) of some zooplankters in eutrophic lakes is often com- pressed during peak hypoxia. To better understand the indirect consequences of seasonal hypolimnetic hypoxia, we integrated laboratory-based experimental and field-based observa- tional approaches to quantify how compressed DVM can affect growth of a cladoceran, Daphnia mendotae, in central Lake Erie, North America. To evaluate hypoxia tolerance of D. mendotae, we conducted a survivorship experiment with varying dissolved oxygen concentrations, which −1 demonstrated high sensitivity of D. mendotae to hypoxia (≤2 mg O2 l ), supporting the field obser- vations of their behavioral avoidance of the hypoxic hypolimnion. -
As an Approach to the Cretaceous–Palaeogene Mass Extinction Event F
Geobiology (2009), 7, 533–543 DOI: 10.1111/j.1472-4669.2009.00213.x The environmental disaster of Aznalco´llar (southern Spain) as an approach to the Cretaceous–Palaeogene mass extinction event F. J. RODRI´ GUEZ-TOVAR1 ANDF.J.MARTI´ N-PEINADO2 1Departamento de Estratigrafı´a y Paleontologı´a, Universidad de Granada, Granada, Spain 2Departamento de Edafologı´a, Universidad de Granada, Granada, Spain ABSTRACT Biotic recovery after the Cretaceous–Palaeogene (K–Pg) impact is one unsolved question concerning this mass extinction event. To evaluate the incidence of the K–Pg event on biota, and the subsequent recovery, a recent environmental disaster has been analysed. Areas affected by the contamination disaster of Azna´ lcollar (province of Sevilla, southern Spain) in April 1998 were studied and compared with the K–Pg event. Several similarities (the sudden impact, the high levels of toxic components, especially in the upper thin lamina and the incidence on biota) and differences (the time of recovery and the geographical extension) are recognized. An in-depth geochemical analysis of the soils reveals their acidity (between 1.83 and 2.11) and the high concentration ) of pollutant elements, locally higher than in the K–Pg boundary layer: values up to 7.0 mg kg 1 for Hg, ) ) ) ) 2030.7 mg kg 1 for As, 8629.0 mg kg 1 for Pb, 86.8 mg kg 1 for Tl, 1040.7 mg kg 1 for Sb and 93.3– 492.7 p.p.b. for Ir. However, less than 10 years after the phenomenon, a rapid initial recovery in biota colonizing the contaminated, ‘unfavourable’, substrate is registered. -
Regime Shifts Between Macrophytes and Phytoplankton – Concepts Beyond Shallow Lakes, Unravelling Stabilizing Mechanisms and Practical Consequences
Limnetica, 29 (2): x-xx (2011) Limnetica, 34 (2): 467-480 (2015). DOI: 10.23818/limn.34.35 c Asociación Ibérica de Limnología, Madrid. Spain. ISSN: 0213-8409 Regime shifts between macrophytes and phytoplankton – concepts beyond shallow lakes, unravelling stabilizing mechanisms and practical consequences Sabine Hilt∗ Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Müggelseedamm 301, 12587 Berlin, Germany. ∗ Corresponding author: [email protected] 2 Received: 04/11/2014 Accepted: 11/06/2015 ABSTRACT Regime shifts between macrophytes and phytoplankton – concepts beyond shallow lakes, unravelling stabilizing mechanisms and practical consequences Feedback mechanisms between macrophytes and water clarity resulting in the occurrence of alternative stable states have been described in a theoretical concept for shallow lakes. Here, I review recent studies applying the concept to other freshwater systems, unravelling stabilizing mechanisms and discussing consequences of regime shifts. Recent modelling studies predict that abrupt changes between clear and turbid water states can also occur in lowland rivers, both in time and in space. These findings were supported by long-term data from rivers in Spain and Germany. A deep lake model revealed that submerged macrophytes may also significantly reduce phytoplankton biomass by 50-15 % in 100-11 m deep and oligotrophic lakes. Some of the mechanisms stabilizing clear-water conditions are still far from fully understood. Available data suggest that the macrophyte community composition affects number and type of mechanisms stabilizing clear-water conditions. Allelopathic effects of macrophytes on phytoplankton are no longer doubted, however, bacterial colonization of macrophytes and phytoplankton, phytoplankton interactions, local adaptations and strain-specific sensitivities have been found to modulate these interactions. -
Top-Down Trophic Cascades in Three Meromictic Lakes Tanner J
Top-down Trophic Cascades in Three Meromictic Lakes Tanner J. Kraft, Caitlin T. Newman, Michael A. Smith, Bill J. Spohr Ecology 3807, Itasca Biological Station, University of Minnesota Abstract Projections of tropic cascades from a top-down model suggest that biotic characteristics of a lake can be predicted by the presence of planktivorous fish. From the same perspective, the presence of planktivorous fish can theoretically be predicted based off of the sampled biotic factors. Under such theory, the presence of planktivorous fish contributes to low zooplankton abundances, increased zooplankton predator-avoidance techniques, and subsequent growth increases of algae. Lakes without planktivorous fish would theoretically experience zooplankton population booms and subsequent decreased algae growth. These assumptions were used to describe the tropic interactions of Arco, Deming, and Josephine Lakes; three relatively similar meromictic lakes differing primarily from their absence or presence of planktivorous fish. Due to the presence of several other physical, chemical, and environmental factors that were not sampled, these assumptions did not adequately predict the relative abundances of zooplankton and algae in a lake based solely on the fish status. However, the theory did successfully predict the depth preferences of zooplankton based on the presence or absence of fish. Introduction Trophic cascades play a major role in the ecological composition of lakes. One trophic cascade model predicts that the presence or absence of piscivorous fishes will affect the presence of planktivorous fishes, zooplankton size and abundance, algal biomass, and 1 subsequent water clarity (Fig. 1) (Carpenter et al., 1987). The trophic nature of lakes also affects animal behavior, such as the distribution patterns of zooplankton as a predator avoidance technique (Loose and Dawidowicz, 1994). -
Phosphorus Relese from Oxic
PHOSPHORUS RELEASE FROM SEDIMENTS IN SHAWANO LAKE, WISCONSIN by DARRIN HOVERSON A thesis submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE IN NATURAL RESOURCES (WATER RESOURCES) COLLEGE OF NATURAL RESOURCES UNIVERSITY OF WISCONSIN STEVENS POINT, WISCONSIN FEBRUARY 2008 ABSTRACT The release of phosphorus (P) from lake sediments to the water column is important to lake water quality. Previous research on sediment P release has largely been in deeper, stratified lakes where hypolimnetic anoxia can lead to very high sediment P release rates. Recent studies suggest that sediment P release may also be important in large shallow lakes. Sediment P release in shallow lakes is poorly understood, and it is important that lake managers have a better understanding of how it influences lake nutrient budgets. This research developed a P budget for Shawano Lake, a large shallow lake in north central Wisconsin, and used the sediment P release to explain the difference between measured loads and summer P increases in the lake. Laboratory derived P release rates from intact sediment cores taken from littoral areas of Shawano Lake exhibit mean P release rates that are high under anoxic conditions (1.25 mg m-2 d-1) and lower, although still significant, under oxic conditions (0.25 mg m-2 d-1). When compared to the other components of the summer P budget, internal sediment P load accounted for 71% (46% to 81% range) of the summer P budget. This P release could be explained with an oxic P release rate of 0.31 mg m-2 d-1 (0.10 to 0.49 mg m-2 d-1 range). -
The Value of Kol River Salmon Refuge's Ecosystem Services
REPORT The Value of Kol River Salmon Refuge’s Ecosystem Services Research conducted by University of Vermont’s Department of Community Development & Applied Economics and Gund Institute for Ecological Economics Authored by: Charles Kerchner, Roelof Boumans, and William Boykin-Morris Date Report: November 23, 2008 Prepared for and funded by: Wild Salmon Center List of Tables and Figures………………………………………………………………………………...……………….iii Executive Summary….......………………………………………………………………………………..………………….iv Chapter 1: Introduction………………………………………………………………………………………………………1 1.1 Research Objective.……………………………………………………………………………………2 1.2 Background…………………………………………………………………..………..2 Chapter 2: Ecosystem Goods, Ecosystem Services, and Market Failure………………...…………4 2.1 Why Is This Important?…………………………………………….……………………………….5 2.2 Valuation Typology……………………………………………………………………...…………….6 Chapter 3: Methods 3.1 Step 1: Ecosystem Service Quantification in KOL RAV Model……...…...…10 3.1.1 Metadata: GIS Data Used for Land Use Land Cover...…………………....11 3.2 Ecosystem Service Valuatin in KOL RAV Model……………………………...……13 3.2.1 Benefits Transfer………………………………..………………………………………......…13 3.2.2 Benefits Transfer – Meta-analysis………………………………………...…………14 3.2.3 Site Specific Valuation for Water Surface ……………………………….…….18 3.3 Step 3 & 4: Kol Refuge Ecosystem Service Evaluation Model (KRESEM)………………………..………………...23 3.3.1 Step 3: GIS Compnonent of KRESEM…………………………………..……….24 3.3.2 Step 4: Development of SIMILE Interface and Land Cover Change Scenarios………………………………….……...25 Chapter 4: Results………………………………………………………………………………………………………...…..26 -
Ecological Features and Processes of Lakes and Wetlands
Ecological features and processes of lakes and wetlands Lakes are complex ecosystems defined by all system components affecting surface and ground water gains and losses. This includes the atmosphere, precipitation, geomorphology, soils, plants, and animals within the entire watershed, including the uplands, tributaries, wetlands, and other lakes. Management from a whole watershed perspective is necessary to protect and maintain healthy lake systems. This concept is important for managing the Great Lakes as well as small inland lakes, even those without tributary streams. A good example of the need to manage from a whole watershed perspective is the significant ecological changes that have occurred in the Great Lakes. The Great Lakes are vast in size, and it is hard to imagine that building a small farm or home, digging a channel for shipping, fishing, or building a small dam could affect the entire system. However, the accumulation of numerous human development activities throughout the entire Great Lakes watershed resulted in significant changes to one of the largest freshwater lake systems in the world. The historic organic contamination problems, nutrient problems, and dramatic fisheries changes in our Great Lakes are examples of how cumulative factors within a watershed affect a lake. Habitat refers to an area that provides the necessary resources and conditions for an organism to survive. Because organisms often require different habitat components during various life stages (reproduction, maturation, migration), habitat for a particular species may encompass several cover types, plant communities, or water-depth zones during the organism's life cycle. Moreover, most species of fish and wildlife are part of a complex web of interactions that result in successful feeding, reproduction, and predator avoidance. -
Metalimnetic Oxygen Minimum in Green Lake, Wisconsin
Michigan Technological University Digital Commons @ Michigan Tech Dissertations, Master's Theses and Master's Reports 2020 Metalimnetic Oxygen Minimum in Green Lake, Wisconsin Mahta Naziri Saeed Michigan Technological University, [email protected] Copyright 2020 Mahta Naziri Saeed Recommended Citation Naziri Saeed, Mahta, "Metalimnetic Oxygen Minimum in Green Lake, Wisconsin", Open Access Master's Thesis, Michigan Technological University, 2020. https://doi.org/10.37099/mtu.dc.etdr/1154 Follow this and additional works at: https://digitalcommons.mtu.edu/etdr Part of the Environmental Engineering Commons METALIMNETIC OXYGEN MINIMUM IN GREEN LAKE, WISCONSIN By Mahta Naziri Saeed A THESIS Submitted in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE In Environmental Engineering MICHIGAN TECHNOLOGICAL UNIVERSITY 2020 © 2020 Mahta Naziri Saeed This thesis has been approved in partial fulfillment of the requirements for the Degree of MASTER OF SCIENCE in Environmental Engineering. Department of Civil and Environmental Engineering Thesis Advisor: Cory McDonald Committee Member: Pengfei Xue Committee Member: Dale Robertson Department Chair: Audra Morse Table of Contents List of figures .......................................................................................................................v List of tables ....................................................................................................................... ix Acknowledgements ..............................................................................................................x