Glibert
Patricia M.
Glibert
Patricia M.
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PreprintOcean urea fertilization for carbon credits poses high ecological risks( 2008) Glibert, Patricia M. ; Azanza, Rhodora ; Burford, Michele ; Furuya, Ken ; Abal, Eva ; Al-Azri, Adnan ; Al-Yamani, Faiza ; Andersen, Per ; Anderson, Donald M. ; Beardall, John ; Berg, Gry M. ; Brand, Larry E. ; Bronk, Deborah ; Brookes, Justin ; Burkholder, JoAnn M. ; Cembella, Allan D. ; Cochlan, William P. ; Collier, Jackie L. ; Collos, Yves ; Diaz, Robert ; Doblin, Martina ; Drennen, Thomas ; Dyhrman, Sonya T. ; Fukuyo, Yasuwo ; Furnas, Miles ; Galloway, James ; Graneli, Edna ; Ha, Dao Viet ; Hallegraeff, Gustaaf M. ; Harrison, John A. ; Harrison, Paul J. ; Heil, Cynthia A. ; Heimann, Kirsten ; Howarth, Robert W. ; Jauzein, Cecile ; Kana, Austin A. ; Kana, Todd M. ; Kim, Hakgyoon ; Kudela, Raphael M. ; Legrand, Catherine ; Mallin, Michael ; Mulholland, Margaret R. ; Murray, Shauna A. ; O’Neil, Judith ; Pitcher, Grant C. ; Qi, Yuzao ; Rabalais, Nancy ; Raine, Robin ; Seitzinger, Sybil P. ; Salomon, Paulo S. ; Solomon, Caroline ; Stoecker, Diane K. ; Usup, Gires ; Wilson, Joanne ; Yin, Kedong ; Zhou, Mingjiang ; Zhu, MingyuanThe proposed plan for enrichment of the Sulu Sea, Philippines, a region of rich marine biodiversity, with thousands of tonnes of urea in order to stimulate algal blooms and sequester carbon is flawed for multiple reasons. Urea is preferentially used as a nitrogen source by some cyanobacteria and dinoflagellates, many of which are neutrally or positively buoyant. Biological pumps to the deep sea are classically leaky, and the inefficient burial of new biomass makes the estimation of a net loss of carbon from the atmosphere questionable at best. The potential for growth of toxic dinoflagellates is also high, as many grow well on urea and some even increase their toxicity when grown on urea. Many toxic dinoflagellates form cysts which can settle to the sediment and germinate in subsequent years, forming new blooms even without further fertilization. If large-scale blooms do occur, it is likely that they will contribute to hypoxia in the bottom waters upon decomposition. Lastly, urea production requires fossil fuel usage, further limiting the potential for net carbon sequestration. The environmental and economic impacts are potentially great and need to be rigorously assessed.
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ArticleModels : tools for synthesis in international oceanographic research programs(Oceanography Society, 2010-09) McGillicuddy, Dennis J. ; deYoung, Brad ; Doney, Scott C. ; Glibert, Patricia M. ; Stammer, Detlef ; Werner, Francisco E.Through its promotion of coordinated international research programs, the Intergovernmental Oceanographic Commission (IOC) has facilitated major progress on some of the most challenging problems in oceanography. Issues of global significance—such as general ocean circulation, the carbon cycle, the structure and dynamics of ecosystems, and harmful algal blooms—are so large in scope that they require international collaboration to be addressed systematically. International collaborations are even more important when these issues are affected by anthropogenic processes— such as climate change, CO2 enhancement, ocean acidification, pollution, and eutrophication—whose impacts may differ greatly throughout the global ocean. These problems require an entire portfolio of research activities, including global surveys, regional process studies, time-series observations, laboratorybased investigations, and satellite remote sensing. Synthesis of this vast array of results presents its own set of challenges (Hofmann et al., 2010), and models offer an explicit framework for integration of the knowledge gained as well as detailed investigation of the underlying dynamics. Models help us to understand what happened in the past, and to make predictions of future changes—both of which support the development of sound policy and decision making. We review examples of how models have been used for this suite of purposes, focusing on areas where IOC played a key role in organizing and coordinating the research activities.
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PreprintBarnegat Bay-Little Egg Harbor Estuary : case study of a highly eutrophic coastal bay system( 2006-09-26) Kennish, Michael J. ; Bricker, Suzanne B. ; Dennison, William C. ; Glibert, Patricia M. ; Livingston, Robert J. ; Moore, Kenneth A. ; Noble, Rachel T. ; Paerl, Hans W. ; Ramstack, Joy M. ; Seitzinger, Sybil P. ; Tomasko, David A. ; Valiela, IvanThe Barnegat Bay-Little Egg Harbor Estuary is classified here as a highly eutrophic estuary based on application of NOAA’s National Estuarine Eutrophication Assessment model. Because it is shallow, poorly flushed, and bordered by highly developed watershed areas, the estuary is particularly susceptible to the effects of nutrient loading. Most of this load (~50%) is from surface water inflow, but substantial fractions also originate from atmospheric deposition (~39%), and direct groundwater discharges (~11%). No point source inputs of nutrients exist in the Barnegat Bay watershed. Since 1980, all treated wastewater from the Ocean County Utilities Authority's regional wastewater treatment system has been discharged 1.6 km offshore in the Atlantic Ocean. Eutrophy causes problems in this system, including excessive micro- and macroalgal growth, harmful algal blooms (HABs), altered benthic invertebrate communities, impacted harvestable fisheries, and loss of essential habitat (i.e., seagrass and shellfish beds). Similar problems are evident in other shallow lagoonal estuaries of the Mid-Atlantic and South Atlantic regions. To effectively address nutrient enrichment problems in the Barnegat Bay-Little Egg Harbor Estuary, it is important to determine the nutrient loading levels that produce observable impacts in the system. It is also vital to continually monitor and assess priority indicators of water quality change and estuarine health. In addition, the application of a new generation of innovative models using web-based tools (e.g., NLOAD) will enable researchers and decision-makers to more successfully manage nutrient loads from the watershed. Finally, the implementation of stormwater retrofit projects should have beneficial effects on the system.
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ArticleThe global, complex phenomena of harmful algal blooms(Oceanography Society, 2005-06) Glibert, Patricia M. ; Anderson, Donald M. ; Gentien, Patrick ; Graneli, Edna ; Sellner, Kevin G.Marine and fresh waters team with life, much of it microscopic, and most of it harmless; in fact, it is this microscopic life on which all aquatic life ultimately depends for food. Microscopic algae also play an important role in regulating atmospheric CO2 by sequestering it during production and transporting it to deeper waters. Yet some of the microscopic “algae” cause problems when they accumulate in sufficient numbers, due either to their production of endogenous toxins, or to their sheer biomass or even their physical shape. These are known as the harmful algae, or, when in sufficient numbers, harmful algal blooms (HABs). These blooms were formerly called “red tides” because many were composed of dinoflagellates containing red pigments that in high densities colored the water red, but blooms may also be green, yellow, or brown, depending on the type of algae present and their pigmentation. As with all blooms, their proliferation results from a combination of physical, chemical, and biological mechanisms and their interactions with other components of the food web that are for the most part poorly understood. Most HABs are dinoflagellates or cyanobacteria, but other classes of algae, including diatoms, have members that may form HABs under some conditions. As stated by J. Ryther and co-workers many years ago, “...there is no necessity to postulate obscure factors which would account for a prodigious growth of dinoflagellates to explain red water. It is necessary only to have conditions favoring the growth and dominance of a moderately large population of a given species, and the proper hydrographic and meteorological conditions to permit the accumulation of organisms at the surface and to effect their future concentrations in localized areas” (Ryther, 1955).
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PreprintHarmful algal blooms and eutrophication : examining linkages from selected coastal regions of the United States( 2008-07-28) Anderson, Donald M. ; Burkholder, JoAnn M. ; Cochlan, William P. ; Glibert, Patricia M. ; Gobler, Christopher J. ; Heil, Cynthia A. ; Kudela, Raphael M. ; Parsons, Michael L. ; Rensel, J. E. Jack ; Townsend, David W. ; Trainer, Vera L. ; Vargo, Gabriel A.Coastal waters of the United States (U.S.) are subject to many of the major harmful algal bloom (HAB) poisoning syndromes and impacts. These include paralytic shellfish poisoning (PSP), neurotoxic shellfish poisoning (NSP), amnesic shellfish poisoning (ASP), ciguatera fish poisoning (CFP) and various other HAB phenomena such as fish kills, loss of submerged vegetation, shellfish mortalities, and widespread marine mammal mortalities. Here, the occurrences of selected HABs in a selected set of regions are described in terms of their relationship to eutrophication, illustrating a range of responses. Evidence suggestive of changes in the frequency, extent or magnitude of HABs in these areas is explored in the context of the nutrient sources underlying those blooms, both natural and anthropogenic. In some regions of the U.S., the linkages between HABs and eutrophication are clear and well documented, whereas in others, information is limited, thereby highlighting important areas for further research.
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ArticleDefining planktonic protist functional groups on mechanisms for energy and nutrient acquisition : incorporation of diverse mixotrophic strategies(Elsevier, 2016-01-03) Mitra, Aditee ; Flynn, Kevin J. ; Tillmann, Urban ; Raven, John A. ; Caron, David A. ; Stoecker, Diane K. ; Not, Fabrice ; Hansen, Per J. ; Hallegraeff, Gustaaf M. ; Sanders, Robert W. ; Wilken, Susanne ; McManus, George ; Johnson, Matthew D. ; Pitta, Paraskevi ; Våge, Selina ; Berge, Terje ; Calbet, Albert ; Thingstad, Frede ; Jeong, Hae Jin ; Burkholder, JoAnn M. ; Glibert, Patricia M. ; Graneli, Edna ; Lundgren, VeronicaArranging organisms into functional groups aids ecological research by grouping organisms (irrespective of phylogenetic origin) that interact with environmental factors in similar ways. Planktonic protists traditionally have been split between photoautotrophic “phytoplankton” and phagotrophic “microzooplankton”. However, there is a growing recognition of the importance of mixotrophy in euphotic aquatic systems, where many protists often combine photoautotrophic and phagotrophic modes of nutrition. Such organisms do not align with the traditional dichotomy of phytoplankton and microzooplankton. To reflect this understanding, we propose a new functional grouping of planktonic protists in an eco-physiological context: (i) phagoheterotrophs lacking phototrophic capacity, (ii) photoautotrophs lacking phagotrophic capacity, (iii) constitutive mixotrophs (CMs) as phagotrophs with an inherent capacity for phototrophy, and (iv) non-constitutive mixotrophs (NCMs) that acquire their phototrophic capacity by ingesting specific (SNCM) or general non-specific (GNCM) prey. For the first time, we incorporate these functional groups within a foodweb structure and show, using model outputs, that there is scope for significant changes in trophic dynamics depending on the protist functional type description. Accordingly, to better reflect the role of mixotrophy, we recommend that as important tools for explanatory and predictive research, aquatic food-web and biogeochemical models need to redefine the protist groups within their frameworks.
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ArticleTemperature-dependent mixotrophy in natural populations of the toxic dinoflagellate Karenia brevis(MDPI, 2024-05-29) Ahn, So Hyun ; Glibert, Patricia M.Previous studies have revealed that mixotrophs can become more heterotrophic as the temperature rises, although these studies were primarily conducted under laboratory conditions with temperature-acclimated grazers. This study investigated the short-term thermal regulation of grazing and photosynthetic performance, measured in terms of the maximum relative electron transport rate (rETRmax), of natural Karenia brevis populations on cultured Synechococcus. Bloom waters were collected in Sarasota, Florida, during the fall of 2022. Synechococcus were inoculated into K. brevis bloom waters in varying ratios and incubated at an ambient temperature and an ambient temperature ±5 °C (19, 24, and 29 °C). In general, the grazing coefficient, clearance, and ingestion rates were higher in warmer waters, although ingestion rates were significantly regulated by the prey-to-grazer ratios and, to a lesser degree, by temperatures (22 to 204 Synechococcus K. brevis−1 d−1). Overall, the rETRmax of Synechococcus controls generally increased over time with a more substantial increase at warmer temperatures, but, in the presence of grazers, the rETRmax of Synechococcus did not increase, and, remarkably, even decreased in some cases. These findings suggest that grazing on Synechococcus could directly regulate Synechococcus concentrations and indirectly reduce the photosynthetic performance of prey. Furthermore, this study demonstrates that the thermal regulation of grazing and photosynthetic performance can occur on a short-term basis.