DOCSLIB.ORG

Grazing and Zooplankton Production As Key Controls of Phytoplankton Production in the Open Ocean

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Grazing and Zooplankton Production As Key Controls of Phytoplankton Production in the Open Ocean FEATURE GRAZING AND ZOOPLANKTON PRODUCTION AS KEY CONTROLS OF PHYTOPLANKTON PRODUCTION IN THE OPEN OCEAN By Karl Banse THANKS TO NASA's Coastal Zone Color Scan- Phytoplankton Concentrations and Seasonality ner (CZCS, 1978-1986), nearly ocean-wide cov- Regions Without Marked Phytoplankton erage of the distribution of phytoplankton pig- Seasonality ment in the upper part of the euphotic zone and, In much of the open ocean, the seasonal change in effect, in the mixed layer of the open ocean, of phytoplankton pigment and, by implication, of is now available. This coverage includes season- biomass is small. Figure 1 juxtaposes monthly me- ality and interannual variability. The CZCS ob- dians of CZCS-derived pigment of a cool-temper- servations confirm that the physics of the ocean ate area (Fig. la; see Frost, 1991, for regional provide the backbone of the geographic and background), an equatorial area (Fig. lb; see Bar- temporal patterns of pigment distribution and, ber and Chavez, 1991), and a subtropical area by inference, of primary production rate. For ex- (Fig. lc; see Venrick et al., 1987). The first two ample, phytoplankton concentrations and pro- areas are persistently nutrient-rich, the last is per- duction are enhanced where upwelling or sea- sistently nutrient-depleted. Patterns similar to sonal overturn of the water column replenishes those in Fig. la prevail in the subantarctic water nutrient concentrations in the mixed layer, ring (Banse, unpub, observations) that encom- whereas the timing of this enhancement may be passes about N0 of the ocean area; patterns similar controlled by upwelling, seasonal overturn, or to those in Fig. lc prevail in all subtropical central the mixed layer becoming shallower than the gyres that I estimate comprise close to '/3 of the critical depth. ocean area (cf. Banse and English, 1994). I propose that the next task is to understand Figure l a shows that a marked seasonal cycle the cause of the phytoplankton concentrations of incident light in the year-round presence of nu- I propose that the and to be able to predict them and the temporal trients, as observed at -50°N, does not necessarily next task is to rate of change of concentrations on the scale of lead to clear seasonality of phytoplankton, e.g., to several days to seasons. I will show that this spring and fall blooms of several mg m 3 of pig- understand the cause major challenge for biological oceanography ment that supposedly are typical for temperate lat- of the phytoplankton cannot be addressed without a vastly improved itudes. (The 2 values > 1 mg m -3 occur during a understanding of the zooplankton. Understanding season when inaccurate values were recorded by concentrations and to the animals is of intrinsic interest, which is also the CZCS in 1980, Banse and English, 1994). At be able to predict true for phytoplankton. However, the task of pre- the subtropical site (Fig. lc), the trend to seasonal- dicting phytoplankton concentrations and their ity is caused by enhanced vertical mixing and nu- them and the rates of change also may be considered as a sub- trient supply during the cool season. Further, com- set of the challenge of anticipating the effect of parison of Figure 1, b and c indicates that temporal rate of climate change on, e.g., the geographic and tem- drastically different nutrient (N, P) concentrations change of poral (seasonal) distribution of the sign of the have little effect on pigment levels; the same small CO2 gradient between atmosphere and sea via effect holds for the rate of nutrient supply from concentrations on the the connection between phytoplankton concen- below the thermocline at the two sites. The low tration and photosynthesis, or on plankton com- scale of several days pigment levels in situations rich in N and P as in munity composition and its feedback to the at- Figure 1, a and b are not likely to be caused by to seasons. mosphere from changes in the distributions of lack of iron. In or near these areas, phytoplankton DMS producers. enclosed in the control flasks (no iron added) of the recent iron bioassays (mostly by Martin et al., 1991) doubled to quadrupled in biomass over a K. Banse, School of Oceanography, WB-10, University of few days (Martin et al., 1991 for the eastern tropi- Washington, Seattle, WA 98195, USA. cal Pacific; see Banse, 1991a, for the southern OCEANOGRAPHY'VoI.7, NO. l'1994 13 (3 b 1- 0.5 • 1" 1" 0.8- 0.4t i E c~ 0.6 0.3- E o 4> ^ • E]~ E (1.) E 0.4 0.2. C~ {3. • o [] [] 0.2 0.1. • ]t A - <> ~ Vt ~ ~,& 8 1'o 1'2 monlh of yeor month of year C 0.5 d 0.4 • 1978 [] 1982 0 1985 'E tm 0.3 E E • 1979 0 1983 ,O, 1986 (D [] E 0.2 13_ [] • <> <> [] o • • 1988 /k 1984 -- median 0.1 • 1981 o o 2 ~, 6 8 1'o 1'2 month of yeQr Fig. 1: Monthly medians of CZCS-derived pigment m three oceanic domains for 9 years. Medians for each month are connected by lines• The areas are approximately parallelograms with the coordinates of the southwestern, southeastern, and northeastern corners indicated. (a) Subarctic Pacific south of Gulf of Alaska, 45°N, 155°W; 45°N, 138°W; 50°N, 144°W (the last coordinates approximately those of the for- mer Ocean Weather Station PAPA; note reduced scale of ordinate and omitted values [arrows at top margin], 1.16 mg m 3for Sept. 1983 and 1.71 for Oct. 1981). (b) Eastern equatorial Pacific, 6°S, 124°W; 6°S, 97°W; 4°N, 97°W. (c) Central North Pacific around CLIMAX area, 25°N, 160°; 25°N, 144°W; 30°N, 148°W. (d) Symbols for years. (see Banse and English, 1994, for methods). • . the rate of Gulf of Alaska and Antarctic sites), despite more, horizontal advection will average out the ef- change of demonstrated adsorption of iron to the container fect of patchiness of pigment. Thus the horizontal walls. terms in the equation in Figure 2 can be neglected. phytoplankton As to the understanding of the rate of temporal Further, Figure 1 shows that the percentage daily change of pigment due to seasonality, if any, is concentration is change of pigment, only in the last few years have accurate growth rates of bulk phytoplankton be- very small so that d[chl]/dt in Figure 2 can be set principally come available, which permit us to draw up a bal- to zero. Then, the measured rates of cell division k are balanced by the three vertical terms and mor- understandable as ance sheet (Fig. 2; see Banse, 1992, for sources supporting the following discussion). In the geo- tality, g. Since each of the vertical terms is known the balance between graphic domains identified (Fig. 2, bottom part), to be equivalent to a few percent per day, the rate horizontal gradients of pigment are slight, espe- of change of phytoplankton concentration is prin- the rates of cell cially in the zonal direction. Also, considering the cipally understandable as the balance between the division and mortality. time change at a fixed station over a few days or rates of cell division and mortality. 14 OCEANOGRAPHY°VoI. 7, No. 1o1994 mixing, advection _ [Chl]u .I ~ upper ( = euphoric) t adv. mix. sink. ~ lower layers [Chl]l = 0 ~l<,,temp' d [Chl]u dt - [Chl]u (k - a - m - s - g + x) ~, 0 vertical "be k a m s g SUBANTA RCTIC 0.25 0.04 0.05? -<0.02 0.t57 ( Summer) (0.5)-~ SUBARCTIC 0.5 <0.0t ~0.03 0.0t ~0.45 ("Papa", Summer) (0.8)"~ SUBTROPICAL GYRE 1.2 <0.01 <0.01 _<0.01 ~1.2 {t.7)* EQUATORIAL 1.0 0.04 0.02 0.01 ~0.9 UPWELLING (t. 4)* ~max. instant,growth rate Fig. 2: The temporal balance of rates of algal growth and loss in the mixed layer at 4 representative sites of the open sea. The equation, based on the model above, compares the instantaneous rates of growth (k) and loss (a, m, s, g, x, all as d ~) for bulk phytoplankton in the euphotic zone (= mixed layer), which is as- sumed to overlie phytoplankton-free water. The maximal instantaneous rates for the respective tempera- tures also are given, mostly representing diatoms at replete nutrients and light, with varying daylengths taken into account. To obtain division rates (d-~), divide by 0.69; the doubling times (d) are the inverse of the division rates (from Banse, 1992, with permission of Plenum Press). In normal, near-steady state situations with atom cells when counting phytoplankton under the • . cell mortality high algal division rates, as in the domains of Fig- microscope. Even these cells might have died ure 2, cell mortality mainly is caused by grazing. from grazing by heterotrophic dinoflagellates with mainly is caused by Most of the grazing is due to small, unicellular an- digestion outside the cell body, i.e., without break- grazing. imals (protozoans) with division rates that are po- age of the prey (cf. Jacobson and Anderson, tentially similar (given sufficient food) to those of 1986)• the phytoplankton or even higher, so that the ani- Note regarding the grazing term in Figure 2, mals quickly can adjust the grazing pressure to an that g (d ') equals the fraction of water (liter/liter) enhanced food supply and the underlying phyto- that is being cleared of particles per day. With di- plankton production rate. The only other source of visions approaching 2 d ' (3rd line of Fig.
Load more

Recommended publications
  • Biological Oceanography - Legendre, Louis and Rassoulzadegan, Fereidoun
    OCEANOGRAPHY – Vol.II - Biological Oceanography - Legendre, Louis and Rassoulzadegan, Fereidoun BIOLOGICAL OCEANOGRAPHY Legendre, Louis and Rassoulzadegan, Fereidoun Laboratoire d'Océanographie de Villefranche, France. Keywords: Algae, allochthonous nutrient, aphotic zone, autochthonous nutrient, Auxotrophs, bacteria, bacterioplankton, benthos, carbon dioxide, carnivory, chelator, chemoautotrophs, ciliates, coastal eutrophication, coccolithophores, convection, crustaceans, cyanobacteria, detritus, diatoms, dinoflagellates, disphotic zone, dissolved organic carbon (DOC), dissolved organic matter (DOM), ecosystem, eukaryotes, euphotic zone, eutrophic, excretion, exoenzymes, exudation, fecal pellet, femtoplankton, fish, fish lavae, flagellates, food web, foraminifers, fungi, harmful algal blooms (HABs), herbivorous food web, herbivory, heterotrophs, holoplankton, ichthyoplankton, irradiance, labile, large planktonic microphages, lysis, macroplankton, marine snow, megaplankton, meroplankton, mesoplankton, metazoan, metazooplankton, microbial food web, microbial loop, microheterotrophs, microplankton, mixotrophs, mollusks, multivorous food web, mutualism, mycoplankton, nanoplankton, nekton, net community production (NCP), neuston, new production, nutrient limitation, nutrient (macro-, micro-, inorganic, organic), oligotrophic, omnivory, osmotrophs, particulate organic carbon (POC), particulate organic matter (POM), pelagic, phagocytosis, phagotrophs, photoautotorphs, photosynthesis, phytoplankton, phytoplankton bloom, picoplankton, plankton,
    [Show full text]
  • Marine Microbiology at Scripps
    81832_Ocean 8/28/03 7:18 PM Page 67 Special Issue—Scripps Centennial Marine Microbiology at Scripps A. Aristides Yayanos Scripps Institution of Oceanography, University of California, • San Diego, California USA Marine microbiology is the study of the smallest isolated marine bioluminescent bacteria, isolated and organisms found in the oceans—bacteria and archaea, characterized sulfate-reducing bacteria, and showed many eukaryotes (among the protozoa, fungi, and denitrifying bacteria could both produce and consume plants), and viruses. Most microorganisms can be seen nitrous oxide, now known to be an important green- only with a microscope. Microbes pervade the oceans, house gas. Beijerinck also founded the field of virology its sediments, and some hydrothermal fluids and through his work on plant viruses (van Iterson et al., exhibit solitary life styles as well as complex relation- 1983). Mills (1989) describes the significance of the ships with animals, other microorganisms, and each work of Beijerink and Winogradsky to plankton other. The skeletal remains of microorganisms form the research and marine chemistry. largest component of sedimentary fossils whose study Around 1903, bacteriology in California was reveals Earth’s history. The enormous morphological, emerging in the areas of medicine and public health physiological, and taxonomic diversity of marine and accordingly was developing into an academic dis- microorganisms remains far from adequately cipline in medical schools (McClung and Meyer, 1974). described and studied. Because the sea receives terres- Whereas the branch of microbiology dealing with bac- trial microorganisms from rivers, sewage outfalls, and teria and viruses was just beginning, the branch con- other sources, marine microbiology also includes the cerning protozoa and algae was a relatively more estab- study of alien microorganisms.
    [Show full text]
  • Biological Oceanography
    MEETINGS & WORKSHOPS BOOKS & VIDEOS COMPARISON OF BIOLOGICALOCEANOGRAPHY: TERRES ,C AN EARLY I--hSTOR¥, 1870 TO 1960 MARINE ECOLOGICAL SYSTEMS By Eric L. Mills A WORKSHOP on this subject 1989,378 pp., $42.50, Cloth, Cornell University Press, Ithaca, NY. was held in 1989 with partial National Reviewed by David J. Carlson Science Foundation support. The re- In the mid-nineteenth century, biologists dence), the initial biological oceanographers port (copies available from J. Steele) studying the oceans were mostly interested were male (Sheina Marshall of the Scottish discusses the various problems, lo- in discovering deep-sea organisms. Today Marine Biological Association laboratory gistic and conceptual, in making such biological oceanographers pay most atten- and Penelope Jenkin and Marie Lebour of the comparisons, but its main conclu- tion to processes in the surface ocean. In his Plymouth Laboratoryare notable exceptions). sion is that we should have work- latest volume of oceanographic history, Mills introduces us first to Victor Hensen, a shops or summer schools that focus published by Cornell University Press in its German biochemist, anatomist and physi- on specific topics where interactions History of Science Series, Eric Mills de- ologist who turned his attention to marine between the different sectors would scribes the period from 1870 to 1960 during subjects when nascent Germany formed a be most fruitful. A recent meeting of which focus shifted from deep-sea natural commission for the study of its seas. Hensen the Steering Committee (J. Cohen, P. history to upper ocean plankton dynamics recognized that small planktonic organisms Dayton, T. Kratz, S. Levin, R. and when, as a result, biological oceanogra- were important components of marine sys- Ricklefs and J.
    [Show full text]
  • Biological Oceanography in Canada (With Special Reference to Federal Government Science)
    PROC. N.S. INST. SCI. (2006) Volume 43, Part 2, pp. 129-158 BIOLOGICAL OCEANOGRAPHY IN CANADA (WITH SPECIAL REFERENCE TO FEDERAL GOVERNMENT SCIENCE) W. G. HARRISON Ecosystem Research Division, Science Branch Department of Fisheries and Oceans, Maritimes Region Bedford Institute of Oceanography PO Box 1006 Dartmouth, Nova Scotia B2Y 4A2 This is a personal account of the history, accomplishments and future of biological oceanography in Canada with emphasis on Canadian government research. Canadian biological oceanographers have a rich history pre-dating the formal beginning of marine scientific research in the country with the establishment of the St Andrews and Nanaimo field stations in the early 1900s. Over the years, they have distinguished themselves by being leaders in the early developments of the discipline, including methodologies, concepts and understanding of both the pelagic and benthic ecosystems. In more recent years, Canadian biological oceanographers have led in the conceptualization, planning and implementation of major interdisciplinary/international research initiatives on climate change and ecosystem dynamics. Additionally, they are making important contributions to ecosystem and climate monitoring, research aimed at understanding the influence of ecosystems on harvestable living resource variability and on climate change, and development and application of ecosystem and climate models. Canadian biological oceanographers have made and continue to make significant contributions to the understanding of the biology of the oceans and its interactions with the physical, chemical and geological world. The challenge of solving the complex scientific and societal problems of the future will require better planning, coordination and stronger commitment to the ocean sciences by universities and government than is currently in place.
    [Show full text]
  • Biological Oceanography (3 Credits) Class Number: 26773 Section: 1003 MWF Period 2 8:30Am-9:20Am Larsen Hall 0310
    SYLLABUS: BSC4930 Special Topics in Biology: Biological Oceanography (3 credits) Class number: 26773 Section: 1003 MWF Period 2 8:30am-9:20am Larsen Hall 0310 INSTRUCTOR: Bryndan P. Durham (she/her) Office Hours: by appointment Office: Cancer and Genetics Research Complex Rm 404 Phone: (352) 294-6312 (office) Email: [email protected] COURSE DESCRIPTION: Biological oceanography is the study of marine organisms, their quantitative distributions in time and space, and their interactions with each other and their ocean environment. In this course, we cover the basics of biological, physical, and chemical dynamics in the oceans with a particular emphasis on life in different ocean environments. Specific topics include primary production by phytoplankton, secondary production by zooplankton, bacterial production and remineralization, distributions of pelagic and benthic organisms, and the energy and nutrient cycles driven by these organisms. In the final portion of the course, we explore the impacts of human perturbations and global climate change on ocean ecosystems and their inhabitants. Pre-requisites: BSC 2010, BSC2011, and BSC 2010L/2011L COURSE GOALS & STUDENT LEARNING OUTCOMES: Through reading, watching, and/or listening to assigned materials, attending in-class lectures, completing written and oral assignments, and participating in group discussions, you will gain experience toward the following broad university curricular goals: 1. The ability to think logically, analytically, and independently; 2. The ability to communicate clearly and effectively, both orally and in writing; and 3. The ability to learn on one’s own and as part of a group. More specific to topics in Biological Oceanography, you will achieve the following learning outcomes: 1.
    [Show full text]
  • A Data Assimilative Marine Ecosystem Model of the Central Equatorial Pacific
    Journalof MarineResearch, 59, 859– 894,2001 Adataassimilative marineecosystem modelof the central equatorialPaci c: Numerical twinexperiments byMarjorieA. M.Friedrichs 1 ABSTRACT Ave-component,data assimilative marine ecosystem model is developed for the high-nutrient low-chlorophyllregion of thecentral equatorial Paci c (0N,140W). Identical twin experiments, in whichmodel-generated synthetic ‘ data’are assimilated into the model, are employed to determine thefeasibility of improving simulation skill by assimilating in situ cruisedata (plankton, nutrients andprimary production) and remotely-sensed ocean color data. Simple data assimilative schemes suchas data insertion or nudging may be insuf cient for lower trophic level marine ecosystem models,since they require long time-series of daily to weekly plankton and nutrient data as wellas adequateknowledge of the governing ecosystem parameters. In contrast, the variational adjoint technique,which minimizes model-data mis ts byoptimizingtunable ecosystem parameters, holds muchpromise for assimilating biological data into marine ecosystem models. Using sampling strategiestypical of those employed during the U.S. JointGlobal Flux Study (JGOFS) equatorial Pacic processstudy and the remotely-sensed ocean color data available from the Sea-viewing Wide Field-of-viewSensor (SeaWiFS), parameters that characterize processes such as growth, grazing, mortality,and recycling can be estimated. Simulation skill is improved even if synthetic data associatedwith 40% random noise are assimilated; however, the presence of biases of 10 – 20% provesto be more detrimental to the assimilation results. Although increasing the length of the assimilatedtime series improves simulation skill if randomerrors are present in the data, simulation skillmay deterior ateas more biased data are assimilat ed.As biologic aldatasets, includin g in situ, satelliteand acoustic sources, continue to grow, data assimilat ivebiologic al-physical modelswill play an increasin glycrucial role in large interdis ciplinaryoceanogr aphicobserva- tionalprograms .
    [Show full text]
  • Oceanography, the Study of All Aspects of the Oceans, Is a Very Complex Discipline, and Many Terms Have Been Applied to Describe Its Components
    Statement on Educational Backgrounds of Marine Science Faculty Oceanography, the study of all aspects of the oceans, is a very complex discipline, and many terms have been applied to describe its components. Marine Science is considered a synonym for Oceanography, and so our college is called the USF College of Marine Science, or CMS. The fundamental concepts of Oceanography have been divided into four groups that, taken together, apply to or cover all of the major processes within the oceans. Not surprisingly, the four groups are aligned with four major academic sciences: physics, chemistry, biology, and geology. Physical oceanography emphasizes the circulation of ocean water at all depths and all time-and- space scales. It is concerned with the distribution of the Sun’s heat, the effects of prevailing and occasional winds, the impact of tides, and frictional and other interactions at the ocean’s boundaries. Ocean-atmosphere interaction and dynamics also play a major role in the study of ocean physics, and theoretical principles of fluid dynamics are readily transformed to the study of the ocean, the most massive accumulation of fluid on the Earth’s surface. Chemical Oceanography, sometimes called Marine Chemistry, considers all of the dissolved and particulate components in the ocean that might become involved in chemical reactions, both biologically influenced and biologically independent, on virtually all time scales from nanoseconds to millions of years. Some of these components are: inorganic ions like magnesium or chloride that exist in high concentrations, minor or trace substances like nitrate or iron that are quite reactive on short time scales, various particles like biological organic debris or minerals, dissolved atmospheric gases like oxygen or carbon dioxide, and stable and radioactive isotopes like carbon-13 or tritium that provide time clocks for or details of chemical processes.
    [Show full text]
  • Zooplankton Mortality Effects on the Plankton Community of the Northern
    https://doi.org/10.5194/bg-2020-417 Preprint. Discussion started: 9 December 2020 c Author(s) 2020. CC BY 4.0 License. Zooplankton mortality effects on the plankton community of the Northern Humboldt Current System: Sensitivity of a regional biogeochemical model Mariana Hill Cruz1, Iris Kriest1, Yonss Saranga José1, Rainer Kiko2, Helena Hauss1,3, and Andreas Oschlies1,3 1GEOMAR Helmholtz Centre for Ocean Research Kiel, Düsternbrooker Weg 20, 24105 Kiel, Germany 2Sorbonne Université, Laboratoire d’Océanographie de Villefranche-sur-mer, France 3Christian-Albrechts-University Kiel, Germany Correspondence: Mariana Hill Cruz ([email protected]) Abstract. Small pelagic fish off the coast of Peru in the Eastern Tropical South Pacific (ETSP) support around 10% of the global fish catches. Their stocks fluctuate interannually due to environmental variability which can be exacerbated by fishing pressure. Because these fish are planktivorous, any change in fish abundance may directly affect the plankton and the biogeochemical 5 system. To investigate the potential effects of variability in small pelagic fish populations on lower trophic levels, we used a coupled physical-biogeochemical model to build scenarios for the ETSP and compare these against an already published reference simulation. The scenarios mimic changes in fish predation by either increasing or decreasing mortality of the model’s large and small zooplankton compartments. 10 The results revealed that large zooplankton was the main driver of the response of the community. Its concentration increased under low mortality conditions and its prey, small zooplankton and large phytoplankton, decreased. The response was opposite, but weaker, in the high mortality scenarios. This asymmetric behaviour can be explained by the different ecological roles of large, omnivorous zooplankton, and small zooplankton, which in the model is strictly herbivorous.
    [Show full text]
  • 6.0 Biological Oceanography 7.0 Chemical Oceanography 8.0 Oceans and Climate Change 9.0 Conclusion
    OCEANOGRAPHY – AN OUTLINE BY PROF.A.BALASUBRAMANIAN Oceanography – an outline Table of Contents 1.0 Introduction 2.0 Scientific Curiosity 3.0 Oceanography -An inter-disciplinary subject 4.0 Geological Oceanography 5.0 Physical Oceanography 6.0 Biological Oceanography 7.0 Chemical Oceanography 8.0 Oceans and Climate change 9.0 Conclusion OBJECTIVES After attending this lesson, the user would be able to understand, basics of oceanography and the wide spectrum of studies carried out in the subject of oceanography. In addition, the concepts, methods, and developments of oceanography and its branches will also be understood. The role of oceanographers and the trends of research activities in the subject of oceanography will be known to progress further in this subject. 1.0 Introduction Oceanography is a science concerned with the physico-chemical characteristics of oceanic water, its depth, temperature, salinity, movements like tides, waves and currents, flora and fauna found at various zones of seas and oceans. As it deals with the distribution and processes of these water bodies, it comes under earth sciences in general. The subject deals with the physical, chemical and biological conditions of oceans. It is an inter-disciplinary subject and an emerging area for marine engineering. It is the science of seas and oceans. Ever since people started sailing the oceans, attempts have been made to map them. Ptolemy’s oldest map is an example. Ocean exploration began around 5000 B.C. with the first ocean diving and the first sailing vessels. Many advances that were made in the subject of oceanography, were all through the great ocean expeditions and explorations.
    [Show full text]
  • Simulating the Ocean's Chlorophyll Dynamic Range from Coastal Upwelling to Oligotrophy
    Progress in Oceanography 168 (2018) 232–247 Contents lists available at ScienceDirect Progress in Oceanography journal homepage: www.elsevier.com/locate/pocean Simulating the ocean’s chlorophyll dynamic range from coastal upwelling to T oligotrophy ⁎ N. Van Oostendea, , R. Dussinb, C.A. Stockc, A.D. Bartond, E. Curchitserb, J.P. Dunnec, B.B. Warda a Department of Geosciences, Princeton University, NJ, USA b Department of Environmental Sciences, Rutgers University, NJ, USA c Geophysical Fluid Dynamics Laboratory, National Oceanic and Atmospheric Administration, Princeton, NJ, USA d Scripps Institution of Oceanography and Section of Ecology, Behavior and Evolution, University of California San Diego, USA ARTICLE INFO ABSTRACT Keywords: The measured concentration of chlorophyll a in the surface ocean spans four orders of magnitude, from Chlorophyll ∼0.01 mg m−3 in the oligotrophic gyres to > 10 mg m−3 in coastal zones. Productive regions encompass only a Coastal upwelling small fraction of the global ocean area yet they contribute disproportionately to marine resources and biogeo- Diatom chemical processes, such as fish catch and coastal hypoxia. These regions and/or the full observed rangeof Coastal hypoxia chlorophyll concentration, however, are often poorly represented in global earth system models (ESMs) used to Phytoplankton community size-structure project climate change impacts on marine ecosystems. Furthermore, recent high resolution (∼10 km) global California Current earth system simulations suggest that this shortfall is not solely due to coarse resolution (∼100 km) of most global ESMs. By integrating a global biogeochemical model that includes two phytoplankton size classes (typical of many ESMs) into a regional simulation of the California Current System (CCS) we test the hypothesis that a combination of higher spatial resolution and enhanced resolution of phytoplankton size classes and grazer linkages may enable global ESMs to better capture the full range of observed chlorophyll.
    [Show full text]
  • The Official Magazine of The
    OceTHE OFFICIALa MAGAZINEnog OF THE OCEANOGRAPHYra SOCIETYphy CITATION Ruzicka, J.J., J.H. Steele, S.K. Gaichas, T. Ballerini, D.J. Gifford, R.D. Brodeur, and E.E. Hofmann. 2013. Analysis of energy flow in US GLOBEC ecosystems using end-to-end models. Oceanography 26(4):82–97, http://dx.doi.org/10.5670/oceanog.2013.77. DOI http://dx.doi.org/10.5670/oceanog.2013.77 COPYRIGHT This article has been published inOceanography , Volume 26, Number 4, a quarterly journal of The Oceanography Society. Copyright 2013 by The Oceanography Society. All rights reserved. USAGE Permission is granted to copy this article for use in teaching and research. Republication, systematic reproduction, or collective redistribution of any portion of this article by photocopy machine, reposting, or other means is permitted only with the approval of The Oceanography Society. Send all correspondence to: [email protected] or The Oceanography Society, PO Box 1931, Rockville, MD 20849-1931, USA. DOWNLOADED FROM HTTP://WWW.TOS.ORG/OCEANOGRAPHY SPECIAL ISSUE ON US GLOBEC: UNDERSTANDING CLIMATE IMPACTS ON MARINE ECOSYSTEMS Analysis of Energy Flow in US GLOBEC Ecosystems Using End-to-End Models BY JAMES J. RUZICKA, JOHN H. STEELE, SARAH K. GAICHAS, TOSCA BALLERINI, DIAN J. GIFFORD, RICHARD D. BRODEUR, AND EILEEN E. HOFMANN Krill and anchovies photos credit: NOAA-NWFSC, FE Division. Jellyfish photo credit: R. Brodeur. Albatross photo credit: J. Ruzicka. 82 Oceanography | Vol. 26, No. 4 ABSTRACT. End-to-end models were constructed to examine and compare the relationships within four US GLOBEC trophic structure and energy flow in coastal shelf ecosystems of four US Global Ocean ecosystems.
    [Show full text]
  • Oceanography CAS NS 221 (3 Credits)
    SEA Semester®: Ocean Exploration Oceanography CAS NS 221 (3 credits) Course Catalog Description (max. 40 words): Explore how interconnected ocean characteristics (bathymetry, seawater chemistry, biological diversity) and processes (plate tectonics, surface and deep-water circulation, biological production) shape global patterns across multiple scales. Discuss destination-specific environmental issues and hot topics in marine research. Instructor(s): Sea Education Association Oceanography Faculty Location: SEA campus in Woods Hole, MA. Prerequisites: Admission to SEA Semester. Course Philosophy and Approach: Oceanography is a six-week course designed to provide students with an understanding of the fundamentals of chemical, physical, biological and geological oceanography. Because field research is vital to the study of oceanography, students will also learn to develop research questions and proposals in preparation for their sea component. As a class, we will determine the scientific agenda of our subsequent research cruise aboard one of SEA’s sailing school vessels. Oceanography thus serves as a precursor to Oceanographic Field Methods and the electives Practical Oceanographic Research and Directed Oceanographic Research, all of which occur during the sea component. This three-credit course consists of 47 contact hours of official instruction, through lectures, labs, research group meetings, visits to local oceanographic institutions and one field trip. The course calendar below provides preliminary details. Learning Outcomes: 1. Gain knowledge of the fundamentals of chemical, physical, biological and geological oceanography, as well as their cross-disciplinary interactions. 2. Understand, from a scientific perspective, anthropogenic pressures on ocean ecosystems. 3. Utilize the scientific method to develop hypotheses and propose experimental methods to describe, explain, and predict natural phenomena; formulate and develop an oceanographic project proposal for research to be undertaken during the subsequent sea component.
    [Show full text]