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There is a lack of standardised imaging methods for marine zooplankton due to the difficulty of manipulating small and often fragile specimens. Yet, standardised 2D photographs and 3D scans provide important morphological information to accompany DNA-barcoded specimens for reference databases such as the Barcode of Life Data System (BOLD). Shelled pteropods are considered as bio-indicators to study impacts of ocean acidification, and thus, it is especially important to obtain high-quality records of their fragile aragonitic shells. We used alcohol-based hand sanitiser gel as a medium for photographing pteropods of the genus Limacina prior to micro-CT scanning and destructive DNA analysis. The high viscosity and transparency of the hand sanitiser enabled easy handling of the specimens so that they could be positioned in a standardised orientation and photographed with a stacking microscope. The high-quality photographs provide a record of morphology and allow for subsequent geometric morphometric analyses. This method did not impact the downstream micro-CT and molecular analyses of the same specimens and resulted in publicly available 2D and 3D digital vouchers as well as ten reference DNA barcodes (partial Cytochrome Oxidase I gene sequences). While alcohol-based hand sanitiser entered our daily lives due to a distressing pandemic, we could make use of it as a cheap and easily available resource to make high quality voucher photographs of shelled pteropods. Digital vouchers serve as a record of their morphology for further taxonomic analyses and facilitate studies assessing shell growth and impacts of ocean acidification.

Nitrogen (N) is essential to the growth and metabolism of life, and it often limits primary productivity in the ocean. Biological N2 fixation is an important source of new N in the euphotic zone of oceanic water, which is mainly conducted by cyanobacterial diazotrophs. Crocosphaera watsonii is a major unicellular cyanobacterial diazotroph that is highly abundant in the warm and oligotrophic waters of tropical and subtropical oceans. In this thesis, we explored the top-down and bottom-up controls on C. watsonii, with specific focus on the effects of microzooplankton grazing and ocean warming. By examining the diel grazing pattern of protistal grazers on C. watsonii and non-diazotrophic unicellular microalgae, we found that all the tested grazers increased grazing selectivity on C. watsonii when C. watsonii was fixing N at night. It suggested that diazotrophs are more nutritious (inferred by C:N ratio) when they are fixing N and may act as an important N source to the microzooplankton in the ocean. In the context of ocean warming, diazotrophs are facing temperature elevation and phosphorus (P) limitation in oceanic waters (as a result of intensifying water stratification). By comparing the physiology of C. watsonii under P-limited and P-replete conditions with temperature gradient, we found that elevated temperature relieved the P limitation of its growth, N2 and CO2 fixation. P use efficiency of C. watsonii increased with temperature under P limitation. As revealed by the expression levels of the genes involved in P metabolism, P recycling and acquisition of C. watsonii were upregulated by both P limitation and temperature elevation. Our results provided new insights to the ecological function and environmental adaptation of an important marine diazotroph, which contributed to the mechanistic understanding of the biogeochemical cycling of the warming ocean.

Knowledge of the structure of the zooplankton allows characterizing marine ecosystems and knowing the interactions (connectance and nestedness) that occur in them. Zooplankton responses to environmental variability bring about fundamental changes in the dynamics of marine ecosystems, causing fluctuation in primary production. Many species of zooplankton within the marine environment has also a key role in the transmission of parasites to higher trophic levels. Since 2004, as a part of a large sampling plan for mesozooplankton in a seasonal upwelling system carried out by the lnstitute of Marine Research (IIM-CSIC), a large number of samples were collected for further research projects. The matter raised was if the Fish Parasite Biobank (FPB) Service already established at the IIM-CSIC would turn the challenge posed by monitoring these samples over time into an opportunity to preserve traceable zooplankton samples and their associated data

Toxicity of polyethylene microplastics (PE-MP) of size ranges similar to their natural food to zooplanktonic organisms representative of the main taxa present in marine plankton, including rotifers, copepods, bivalves, echinoderms and fish, was evaluated. Early life stages (ELS) were prioritized as testing models in order to maximize sensitivity. Treatments included particles spiked with benzophenone-3 (BP-3), a hydrophobic organic chemical used in cosmetics with direct input in coastal areas. Despite documented ingestion of both virgin and BP-3 spiked microplastics no acute toxicity was found at loads orders of magnitude above environmentally relevant concentrations on any of the invertebrate models. In fish tests some effects, including premature or reduced hatching, were observed after 12 d exposure at 10 mg L-1 of BP-3 spiked PE-MP. The results obtained do not support environmentally relevant risk of microplastics on marine zooplankton. Similar approaches testing more hydrophobic chemicals with higher acute toxicity are needed before these conclusions could be extended to other organic pollutants common in marine ecosystems. Therefore, the replacement of these polymers in consumer products must be carefully considered.

Functional traits, rather than taxonomic identity, determine the fitness of individuals in their environment: traits of marine organisms are therefore expected to vary across the global ocean as a function of the environment. Here, we quantify such spatial and seasonal variations based on extensive empirical data and present the first global biogeography of key traits (body size, feeding mode, relative offspring size and myelination) for pelagic copepods, the major group of marine zooplankton. We identify strong patterns with latitude, season and between ocean basins that are partially (c. 50%) explained by key environmental drivers. Body size, for example decreases with temperature, confirming the temperature-size rule, but surprisingly also with productivity, possibly driven by food-chain length and size-selective predation. Patterns unrelated to environmental predictors may originate from phylogenetic clustering. Our maps can be used as a test-bed for trait-based mechanistic models and to inspire next-generation biogeochemical models.

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution May 1998, Planktonic protozoan grazers have the potential to significantly affect the chemistry of particle-associated trace metals. This is due both to the importance of protists as consumers of bacterial-sized particles, and to the unique low-pH, enzyme-rich microenvironment of the grazer food vacuole. This thesis examines the role of protozoan grazers in the marine geochemistry of strongly hydrolyzed, particle-reactive trace metals, in particular Th and Fe. A series of tracer experiments was carried out in model systems in order to determine the effect of grazer-mediated transformations on the chemical speciation and partitioning of radioisotopes C9Fe, 234Th, 51Cr) associated with prey cells. Results indicate that protozoan grazers are equally able to mobilize intracellular and extracellular trace metals. In some cases, protozoan regeneration of trace metals appears to lead to the formation of metal-organic complexes. Protozoan grazing may generate colloidal material that can scavenge trace metals and, via aggregation, lead to an increase in the metal/organic carbon ratio of aggregated particles. Model system experiments were also conducted in order to determine the effect of grazers on mineral phases, specifically colloidal iron oxide (ferrihydrite). Several independent techniques were employed, including size fractionation ors9Fe-labeled colloids, competitive ligand exchange, and iron-limited diatoms as "probes" for bioavailable Fe. Experimental evidence strongly suggests that protozoan grazing can affect the surface chemistry and increase the dissolution rate of iron oxide phases through phagotrophic ingestion. In further work on protozoan-mediated dissolution of colloidal Fe oxides, a novel tracer technique was developed based on the synthesis of colloidal ferrihydrite impregnated with 133Ba as an inert tracer. This technique was shown to be a sensitive, quantitative indicator for the extent of ferrihydrite dissolution/alteration by a variety of mechanisms, including p, This work was financially supported by a Department of Defense ONR-NDSEG Graduate Fellowship, Office ofNaval Research AASERT Award (N00014-94-1-0711), and the National Science Foundation EGB Program (OCE-9523910).

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 1995, This thesis addresses the question, "How do small-scale physics and biology combine to produce dense aggregations of certain species of zooplankton in the Great South Channel (GSC) of the Gulf of Maine?" The thesis consists of three relatively independent parts: an observational study made while following two right whales as they fed on dense patches of the copepod Galanus finmarchicus in the northern GSC; a detailed description of a tightly integrated set of biological and physical observations made in the GSC by means of a new instrument, the Video Plankton Recorder (VPR); and a two-dimensional Eulerian numerical model that simulates one way in which a physical flow field, combined with a biological behavior pattern, may produce dense plankton patches at a convergent front. Part I: Data from a wide variety of instruments was combined to produce a coherent picture of the physical and biological environment near two feeding right whales observed in June, 1989. Instruments included a CTD (with transmissometer), a MOCNESS net system, a 150-kHz ADCP, and a towed acoustic plankton profiler operating at 120 and 200 kHz. Acoustic data were intercalibrated with net-tow data and with "noise" in the transmissometer signal in order to estimate copepod abundance in the plankton patches on which the whales were feeding. One of the whales was observed to reverse course when copepod abundance dropped below about 1.5- 4.5 x 103 copepods/m3 , which is consistent with independent estimates of the density of copepods necessary for a right whale to gain more energy from the prey it ingests than it loses to the extra hydrodynamic drag it experiences while feeding. Part II: The VPR is a towed underwater microscope designed to image plankton non-invasively with sufficient resolution to obtain information on the spatial distribut ion of organisms on scales ranging from millimeters to hundreds of kilometers. CTD instrumentation mounted on the VPR makes it possible to correlate biological a, My first three years in the Joint Program were paid for by the Office of Naval Research under an ONR Fellowship. I would also like to acknowledge subsequent support from the National Science Foundation under grant OCE 93-13671 and the National Oceanic and Atmospheric Administration under grants NA36GP0374 and NA26GP0431.

Ng, Ka Yan., "November 2009.", Thesis (M.Phil.)--Chinese University of Hong Kong, 2010., Includes bibliographical references (leaves 329-399)., s in English and Chinese., Acknowledgements --- p.i, (English) --- p.iv, (Chinese) --- p.ix, Contents --- p.xii, List of Tables --- p.xix, List of Figures --- p.xxi, Chapter Chapter 1 --- General Introduction, Chapter 1.1 --- Seaweeds as Beneficial Resources to Humans --- p.1, Chapter 1.2 --- Seaweed Communities as a Habitat --- p.5, Chapter 1.2.1 --- Reasons for being a Favourable Habitat in the Ocean ´Ø and the Coastal Region --- p.5, Chapter 1.2.2 --- Characteristics of Seagrass Habitat and its Associated Faunal Communities --- p.8, Chapter 1.2.3 --- Characteristics of Seaweed Habitat and its Associated Faunal Communities --- p.9, Chapter 1.2.3.1 --- Seasonality --- p.9, Chapter 1.2.3.2 --- Structural Complexity --- p.10, Chapter 1.2.3.3 --- Canopy Effect on Biota --- p.10, Chapter 1.3 --- Marine Environment and Sargassum Communities in Hong Kong --- p.11, Chapter 1.4 --- Study Organism: the Sargassum siliquastrum --- p.14, Chapter 1.5 --- Study Significance and Objectives --- p.16, Chapter 1.6 --- Study Sites --- p.18, Chapter 1.7 --- Thesis Organization --- p.21, Chapter Chapter 2 --- Zooplankton Assemblage in Seaweed Bed of Sargassum siliquastrum and Its Temporal Variation, Chapter 2.1 --- Introduction --- p.27, Chapter 2.2 --- Materials and Methods --- p.34, Chapter 2.2.1 --- Sample collection --- p.34, Chapter 2.2.2 --- Data acquisition --- p.36, Chapter 2.2.3 --- Data analysis --- p.37, Chapter 2.3 --- Results --- p.39, Chapter 2.3.1 --- Temporal Change in Zooplankton Assemblage Composition --- p.39, Chapter 2.3.1.1 --- Change in Zooplankton Abundance with Time --- p.43, Chapter 2.3.1.2 --- Temporal Change in Zooplankton Species Composition --- p.44, Chapter 2.3.2 --- Effects of Vegetation on Zooplankton Assemblage Structure --- p.47, Chapter 2.3.2.1 --- Comparison between Vegetated and Unvegetated Habitats in terms of Zooplankton Community Structure --- p.47, Chapter 2.3.2.2 --- Comparison between Vegetated and Unvegetated Habitats in terms of Zooplankton Abundance --- p.50, Chapter 2.3.2.3 --- Comparison between Vegetated and Unvegetated Habitats in terms of Zooplankton Species Composition --- p.51, Chapter 2.3.3 --- Temporal Trends of Environmental Factors and their Relationship with Zooplankton Assemblage --- p.58, Chapter 2.3.4 --- Relationship between Zooplankton Assemblage and Seaweed Phenology --- p.59, Chapter 2.4 --- Discussion --- p.61, Chapter 2.4.1 --- Macro-distribution Pattern and Temporal Change in Zooplankton Assemblage Structure in Sargassum siliquastrum Bed --- p.61, Chapter 2.4.2 --- Effects of Vegetation on the Micro-distribution of Zooplankton within and between Habitats ´ؤ Relationship between Sargassum Phenology and the associated Zooplankton Assemblage Structure --- p.66, Chapter 2.4.3 --- Species Composition of Zooplankton Assemblage in Seaweed Bed of Sargassum siliquastrum and its Potential Role as Nursery Ground for Fishery Resources --- p.70, Chapter 2.5 --- Summary and Conclusion --- p.74, Chapter Chapter 3 --- Effects of Seaweed Canopy on the Structure of Zooplankton Assemblage in the Sargassum siliquastrum Bed, Chapter 3.1 --- Introduction --- p.118, Chapter 3.2 --- Materials and Methods --- p.121, Chapter 3.2.1 --- Sample collection --- p.121, Chapter 3.2.2 --- Data acquisition --- p.122, Chapter 3.2.3 --- Data analysis --- p.123, Chapter 3.3 --- Results --- p.125, Chapter 3.3.1 --- Effects of Canopy on Zooplankton Community Structure --- p.125, Chapter 3.3.2 --- "Comparison between Control, Treatment and Unvegetated Habitats in terms of Zooplankton Abundance and Its Temporal Variation" --- p.127, Chapter 3.3.3 --- "Comparison between Control, Treatment and Unvegetated Habitats in terms of Zooplankton Species Composition and Its Temporal Variation" --- p.128, Chapter 3.4 --- Discussion --- p.134, Chapter 3.4.1 --- Effects of Canopy Removal on the Zooplankton Assemblage Structure --- p.134, Chapter 3.4.2 --- Role of Seaweed Canopy in Zooplankton Community and the Potential Impacts of Canopy Removal on the Coastal Ecosystem --- p.137, Chapter 3.5 --- Summary and Conclusion --- p.141, Chapter Chapter 4 --- Epiphytic Faunal Assemblages in Seaweed Bed of Sargassum siliquastrum and its Temporal Variation, Chapter 4.1 --- Introduction --- p.153, Chapter 4.2 --- Materials and Methods --- p.161, Chapter 4.2.1 --- Sample collection --- p.161, Chapter 4.2.2 --- Data acquisition --- p.162, Chapter 4.2.3 --- Data analysis --- p.163, Chapter 4.3 --- Results --- p.165, Chapter 4.3.1 --- Temporal Change in Epiphytic Faunal Assemblage Composition and Comparison among Sites --- p.165, Chapter 4.3.1.1 --- Temporal Change in Epiphytic Faunal Density and Comparison among Sites --- p.171, Chapter 4.3.1.2 --- Temporal Change in Epiphytic Faunal Species Richness and Comparison among Sites --- p.172, Chapter 4.3.1.3 --- Temporal Change in Epiphytic Faunal Species Composition --- p.175, Chapter 4.3.1.4 --- Occurrence of Caprellidean and Its Variation with Seaweed Growth Stages --- p.179, Chapter 4.3.2 --- Temporal Trends of Environmental Factors and their Relationship with Epiphytic Faunal Assemblage --- p.179, Chapter 4.4 --- Discussion --- p.181, Chapter 4.4.1 --- Temporal Change in Epiphytic Faunal Assemblage Structure --- p.181, Chapter 4.4.2 --- Species Composition of Epiphytic Faunal Assemblage in Seaweed Bed of Sargassum siliquastrum and Its Potential Role as Nursery Grounds --- p.191, Chapter 4.4.3 --- Distribution of Epiphytic Fauna in Seaweed Bed of Sargassum siliquastrum among Different Localities --- p.196, Chapter 4.4.4 --- Relationship of Epiphytic Faunal Assemblage with Environmental Factors --- p.197, Chapter 4.5 --- Summary and Conclusion --- p.198, Chapter Chapter 5 --- Relationship of Epiphytic Faunal Assemblage with the Structural Complexity of Seaweed Sargassum siliquastrum, Chapter 5.1 --- Introduction --- p.234, Chapter 5.2 --- Materials and Methods --- p.239, Chapter 5.2.1 --- Sample collection --- p.239, Chapter 5.2.2 --- Data acquisition --- p.241, Chapter 5.2.3 --- Data analysis --- p.243, Chapter 5.3 --- Results --- p.245, Chapter 5.3.1 --- Effects of Macroalgal Structural Complexity on the Associated Epiphytic Faunal Assemblage Structure --- p.245, Chapter 5.3.1.1 --- Effects on Epiphytic Faunal Abundance --- p.245, Chapter 5.3.1.2 --- Effects on Epiphytic Faunal Species Richness --- p.247, Chapter 5.3.1.3 --- Relationship among Parameters of Sargassum siliquastrum --- p.248, Chapter 5.3.2 --- Within-plant Zonation of Epiphytic Faunal Assemblage Structure --- p.249, Chapter 5.3.2.1 --- Within-plant Distribution of Epiphytic Faunal Density --- p.250, Chapter 5.3.2.2 --- Within-plant Distribution of Epiphytic Species Richness --- p.252, Chapter 5.3.2.3 --- Within-plant Distribution of Epiphytic Faunal Species Composition --- p.253, Chapter 5.3.2.4 --- Physical Parameters Associated with Each Zone of Sargassum siliquastrum --- p.257, Chapter 5.4 --- Discussion --- p.260, Chapter 5.4.1 --- Effects of Macroalgal Structural Complexity and Biomass on the Associated Epiphytic Faunal Assemblage Structure --- p.260, Chapter 5.4.2 --- Within-plant Zonation of Epiphytic Faunal Assemblage Structure --- p.264, Chapter 5.5 --- Summary and Conclusion --- p.273, Chapter Chapter 6 --- Synthesis and Perspectives --- p.320, References --- p.329, http://library.cuhk.edu.hk/record=b5896613, Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Lie, An Ying Alice., Thesis submitted in: November 2008., Thesis (M.Phil.)--Chinese University of Hong Kong, 2009., Includes bibliographical references (leaves 115-134)., s in English and Chinese., Chapter Chapter 1. --- Introduction --- p.1, Chapter 1.1. --- Microzooplankton --- p.1, Chapter 1.1.2. --- Microzooplankton grazing --- p.1, Chapter 1.2. --- Dilution method --- p.4, Chapter 1.2.1. --- Basic principles --- p.4, Chapter 1.2.2 --- Variation and extensive uses of the dilution method --- p.7, Chapter 1.2.3. --- Criticism of the dilution method --- p.9, Chapter 1.2.4. --- Results of the dilution experiments and their implications --- p.11, Chapter 1.3. --- The roles of microzooplankton --- p.16, Chapter 1.4. --- Phytoplankton --- p.18, Chapter 1.4.1. --- Size classification --- p.18, Chapter 1.4.2. --- Chemotaxonomic marker pigments --- p.19, Chapter 1.4.3. --- Nutrients and phytoplankton dynamics --- p.19, Chapter 1.5. --- Hypothesis --- p.26, Chapter 1.6. --- Objectives --- p.26, Chapter 1.7 --- Research outline --- p.27, Chapter 1.7.1. --- Microzooplankton grazing rates and phytoplankton growth rates --- p.27, Chapter 1.7.2. --- Phytoplankton group selection --- p.27, Chapter 1.7.3. --- Phytoplankton size selection --- p.27, Chapter 1.8. --- Study sites --- p.27, Chapter 1.81. --- Tolo Harbour --- p.28, Chapter 1.8.2. --- Mirs Bay --- p.28, Chapter 1.8.3. --- Biological and physio-chemical parameters --- p.30, Chapter Chapter 2. --- Materials and methods --- p.33, Chapter 2.1. --- Study site and sampling --- p.33, Chapter 2.2. --- Dilution experiments --- p.33, Chapter 2.2.1. --- Preliminary dilution experiments and enrichment tests --- p.35, Chapter 2.2.2. --- HPLC --- p.37, Chapter 2.2.3. --- Pigment data analysis --- p.41, Chapter 2.2.4. --- Phytoplankton and microzooplankton community analysis --- p.42, Chapter Chapter 3. --- Results --- p.43, Chapter 3.1. --- Field parameters --- p.43, Chapter 3.1.1. --- Physiochemical parameters --- p.43, Chapter 3.1.2. --- Chlorophyll a --- p.46, Chapter 3.2. --- Initial conditions --- p.49, Chapter 3.2.1. --- Phytoplankton pigment and size fraction composition --- p.49, Chapter 3.2.2. --- Microscopy cell counts --- p.56, Chapter 3.3. --- Dilution experiments results --- p.64, Chapter 3.3.1. --- Linear regression analysis results --- p.64, Chapter 3.3.2. --- Estimated pigment specific phytoplankton growth rates and microzooplankton grazing rates --- p.66, Chapter 3.3.3. --- Ratio of microzooplankton grazing to the phytoplankton growth rate in ambient nutrient --- p.70, Chapter 3.4. --- Correlation analyses --- p.78, Chapter 3.4.1. --- Physiochemical parameters --- p.78, Chapter 3.4.2. --- Initial pigment concentration --- p.81, Chapter 3.4.3. --- Initial densities --- p.81, Chapter 3.4.4. --- Phytoplankton growth rates and microzooplankton grazing rates --- p.82, Chapter 3.5. --- Percentage and composition shifts --- p.83, Chapter 3.5.1. --- Percentage change --- p.83, Chapter 3.5.2. --- Size fraction --- p.83, Chapter 3.5.3. --- Pigment markers --- p.83, Chapter Chapter 4. --- Discussions --- p.103, Chapter 4.1. --- Hypothesis --- p.103, Chapter 4.2. --- Phytoplankton growth rates and microzooplankton grazing rates --- p.104, Chapter 4.3. --- Dilution experiment --- p.105, Chapter 4.3.1. --- Nutrient enrichment --- p.105, Chapter 4.3.2. --- Shift of pigment compositions --- p.106, Chapter 4.3.3. --- Experiment limitations --- p.107, Chapter 4.4. --- Microzooplankton feeding preference --- p.108, Chapter 4.4.1. --- Phytoplankton size --- p.108, Chapter 4.4.2. --- Phytoplankton group --- p.109, Chapter 4.5. --- Food web dynamics --- p.110, Chapter 4.5.1. --- The role of microzooplankton --- p.110, Chapter 4.5.1.1. --- Nutrient recycling --- p.110, Chapter 4.5.1.2. --- Energy transfer --- p.111, Chapter 4.5.1.3. --- Phytoplankton control --- p.111, Chapter 4.5.2. --- The role of mesozooplankton --- p.111, Chapter Chapter 5. --- Conclusions --- p.113, References --- p.115, Appendices --- p.135, http://library.cuhk.edu.hk/record=b5893905, Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/)

The main goal of this survey was to study the vertical and horizontal distribution of the thecosome pteropods in the upper 100 m of the western Caribbean Sea. Zooplankton was collected at 60 stations in January 2007 at stratified depth intervals of 25 m from the surface to 100 m. The community was analyzed for diversity, evenness, species richness, and similarity. We recorded 36 taxa 12 of which are new records for the western Caribbean. The most abundant taxa were Limacina inflata, L. trochiformis, Creseis acicula f. clava, Cuvierina columnella atlantica, and Hyalocylis striata. In general, these taxa showed a similar pattern, their highest abundances occurred consistently in 0-25 m layer in both night and day samples; abundance decreased with depth. Significant day/night differences were found in the composition and abundance of pteropods, differences among depth intervals were non-significant. Our results showed that the upper 25 m harbored the highest species richness, diversity, and vertical abundance of pteropods, thus providing unprecedented detail with respect to previous surveys. The local community structure of the pteropods is determined largely by vertical day/night migrations. Pteropods tended to be most abundant in the southern and northern sectors of the area, but highest diversity and species richness were recorded in the central sector. Overall, the low variability of the hydrographic conditions and the mixed horizontal distribution of the clusters from the similarity analysis suggest that day/night migratory patterns of the most abundant taxa are determinant of the observed variability of the pteropod community., El principal objetivo de este estudio fue conocer la distribución vertical y horizontal de los pterópodos tecosomados en la capa superior de los 100 m del Mar Caribe occidental. El zooplancton fue recolectado en 60 estaciones durante enero 2007 en intervalos de profundidad de 25 m desde la superficie a 100 m. La comunidad fue analizada en términos de diversidad, equidad, riqueza y similitud. Encontramos 36 taxa de los que 12 son nuevos registros para el Caribe occidental. Los taxa más abundantes fueron Limacina inflata, L. trochiformis, Creseis acicula f. clava, Cuvierina columnella atlantica y Hyalocylis striata. En general, mostraron un mismo patrón, sus mayores abundancias ocurrieron consistentemente en el estrato 0-25 m de día y noche; la abundancia decrece con la profundidad. Se encontraron diferencias significativas día/ noche en composición y abundancia, no así entre estratos. El estrato de 0-25 m contiene los mayores valores de riqueza, diversidad y abundancia de pterópodos, lo que representa un hallazgo sin precedente respecto a estudios previos. La estructura de la comunidad local está determinada en gran medida por las migraciones verticales día/noche. Los pterópodos tendieron a ser más abundantes en los sectores norte y sur del área, pero su mayor diversidad y riqueza se registró en el sector central. La baja variabilidad de las condiciones hidrográficas y la mezcla horizontal de los grupos generados por el análisis de similitud sugieren que los patrones migratorios día/noche explican la variabilidad observada en la comunidad de pterópodos.

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution August 1979, Colonial radiolarians (Spumellaria) are among the most common and abundant large zooplankton, but they have been little studied by modern biologists. Colonies were found on 98% of epipelagic diving stations in the period from 1977 to 1979. Measured abundances ranged from .04 to 540 colonies per m3. Colony morphology of common genera and species is described and three new shell-less species which reach a length in excess of 1 m are discussed in detail. Some simple behavioral responses are documented, including control of colony buoyancy and position of algae in the colonies. Radiolarians feed on a wide variety of planktonic organisms including tintinnids, copepods, appendicularians, mollusc larvae and hydromedusae. They are hosts to parasitic hyperiid amphipods, particularly those of the genus Hyperietta. Radiolarians are prey of the amphipod Oxycephaius ciausi, an unidentified turbellarian and possibly the Harpacticoid copepods Miracia efferata and Sapphirina sp. Colonial radiolarians are also hosts to symbiotic dinoflagellates. Experiments were done at sea on the net incorporation of CO2 by these algae using 14C labelled NaHC03. Data from these experiments were related to content of carbon and chlorophyll as a function of colony size (cell number). Carbon content of colonies related well with colony size. Mean values were 50, 85, 100 and 200 ng C per radiolarian cell for coiiozoum inerme, C. iongiforme, Acrosphaera spinosa and coiiozoum radiosum respectively. Chlorophyll content varied widely between colonies and chlorophyll per radiolarian cell decreased with increasing colony size in Acrosphaera spinosa. Net carbon incorporation increased with colony size at given light intensities as did phutosynthetic assimilation (mmoles CO2.mg Chl a -l.hr -1) in A. spinosa. In experiments on the effect of light intensity on photosynthesis, there was no evidence for photoinhibition at high intensities in Acrosphaera spinosa. Replicate pieces of the large colonies of C. longifo, This research was supported in part by the Woods Hole Oceanographic Institution Education Program and the National Science Foundation, Oceanographic Section, Grant Nos. OCE75-2l7l5 and OCE77-225ll.

Monstrilloid copepods were collected during zooplankton surveys in the Beagle Channel at the southernmost end of South America. These specimens represent two species of Monstrillopsis, one of them undescribed, and one new species of Monstrilla. Monstrillopsis igniterra n. sp. is related to forms of the M. dubia species group, and particularly to M. ferrarii and M. chilensis. It differs from these species in the relative length of the antennules, the shape and relative size of the genital double and anal somites, details of the antennular armature, and the possession of a short inner caudal seta. The other species of Monstrillopsis, M. chilensis, was previously known only from the Southeast Pacific off Chile, and was originally described from female specimens only. Male individuals found in the Beagle Channel are described and assigned herein to this species. These are the first records of Monstrillopsis from high latitudes of South America. The new species Monstrilla patagonica n.sp. is represented by males. It is characterized by the structure and relative size of the genital lappets, details of the antennular structure, armature, relative size and the number (6) of caudal setae. It belongs to a small group of species with highly modified, pectinate male antennules. A female specimen identified as M. helgolandica 35 years ago from southern

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 2008, Marine ecosystems reflect the physical structure of their environment and the biological processes they carry out. This leads to spatial heterogeneity and temporal variability, some of which is imposed externally and some of which emerges from the ecological mechanisms themselves. The main focus of this thesis is on the formation of spatial patterns in the distribution of zooplankton arising from social interactions between individuals. In the Southern Ocean, krill often assemble in swarms and schools, the dynamics of which have important ecological consequences. Mathematical and numerical models are employed to study the interplay of biological and physical processes that contribute to the observed patchiness. The evolution of social behavior is simulated in a theoretical framework that includes zooplankton population dynamics, swimming behavior, and some aspects of the variability inherent to fluid environments. First, I formulate a model of resource utilization by a stage-structured predator population with density-dependent reproduction. Second, I incorporate the predator-prey dynamics into a spatially-explicit model, in which aggregations develop spontaneously as a result of linear instability of the uniform distribution. In this idealized ecosystem, benefits related to the local abundance of mates are offset by the cost of having to share resources with other group members. Third, I derive a weakly nonlinear approximation for the steady-state distributions of predator and prey biomass that captures the spatial patterns driven by social tendencies. Fourth, I simulate the schooling behavior of zooplankton in a variable environment; when turbulent flows generate patchiness in the resource field, schools can forage more efficiently than individuals. Taken together, these chapters demonstrate that aggregation/ schooling can indeed be the favored behavior when (i) reproduction (or other survival measures) increases with density in part of the range and (ii) mixing o, Funding was provided by the Academic Programs Office of the MIT-WHOI Joint Program, an Ocean Ventures Fund Award, an Anonymous Ys Endowed Science Fellowship, and by NSF grants OCE-0221369 and OCE-336839.

[Truncated abstract] The role of marine microzooplankton in aquatic food webs has been studied in most regions of the world’s oceans, with the exception of the subtropical/temperate eastern Indian Ocean. This thesis addresses this gap in knowledge by investigating microzooplankton from five stations on a cross continental shelf transect and in two mesoscale features ∼300 km offshore of south west Western Australia. My primary focus was to measure and evaluate microzooplankton community change over space and time and their impact on phytoplankton on a cross shelf transect, sampling five stations from February 2002 December 2004 as part of a large multidisciplinary investigation into the pelagic ecosystem on the shelf (Chapter 2). This transect was named the Two Rocks transect. I also investigated an eddy pair (Chapter 5), which had originated from water in the vicinity of the Two Rocks transect, also undertaken as part of a larger study, investigating biophysical coupling within mesoscale eddies off south west Western Australia . . . The distribution of mixotrophic cells differed across the transect. Those mixotrophs that use photosynthesis as their primarily energy source exploited nutrient limited conditions inshore consuming particles, while mixotrophs that are primarily heterotrophic survived low prey conditions offshore by photosynthesizing. In the eddies, the grazing behaviour of microzooplankton was dependent on the specific phytoplankton assemblage in each eddy. The warm core eddy had a resident population of diatoms that were consumed by heterotrophic dinoflagellates present in high numbers. The cold core eddy had a warm cap which prevented upwelled water reaching the surface, resulting in stratification and a very active microbial food web, particularly in the surface, Thesis (Ph.D.)--University of Western Australia, 2006

Submitted to the MIT Department of Biology and the WHOI Biology Department in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2006, The physical and biological forces that drive zooplankton distribution and patchiness in an antarctic continental shelf region were examined, with particular emphasis on the Antarctic krill, Euphausia superba. This was accomplished by the application of acoustic, video, and environmental sensors during surveys of the region in and around Marguerite Bay, west of the Antarctic Peninsula, in the falls and winters of 2001 and 2002. An important component of the research involved the development and verification of methods for extracting estimates of ecologically-meaningful quantities from measurements of scattered sound. The distribution of acoustic volume backscattering at the single frequency of 120 kHz was first examined as an index of the overall biomass of zooplankton. Distinct spatial and seasonal patterns were observed that coincided with advective features. Improved parameterization was then achieved for a theoretical model of Antarctic krill target strength, the quantity necessary in scaling measurements of scattered sound to estimates of abundance, through direct measurement of all necessary model parameters for krill sampled in the study region and survey period. Methods were developed for identifying and delineating krill aggregations, allowing the distribution of krill to be distinguished from that of the overall zooplankton community. Additional methods were developed and verified for estimating the length, abundance, and biomass of krill in each acoustically-identified aggregation. These methods were applied to multifrequency acoustic survey data, demonstrating strong seasonal, inter-annual, and spatial variability in the distribution of krill biomass. Highest biomass was consistently associated with regions close to land where temperatures at depth were cool. Finally, the morphology, internal structure, and vertical position of individual krill aggregations were examined. The observed patterns of variability in aggregation characteristics between day and, Funding was provided by a Fulbright Scholarship, a Natural Sciences and Engineering Research Council of Canada Post-Graduate Scholarship, an Office of Naval Research Graduate Traineeship Award in Ocean Acoustics (Grant N00014-03-1-0212), the Comer Science and Education Foundation, and the Woods Hole Oceanographic Institution (WHOI) Academic Programs Office.

by Tang, Kam Wing., Thesis (M.Phil.)--Chinese University of Hong Kong, 1993., Includes bibliographical references (leaves 139-149)., p.1, Acknowledgements --- p.4, Table of Contents --- p.5, List of Tables --- p.6, List of Figures --- p.7, Chapter Chapter 1 --- General Introduction --- p.11, Chapter Chapter 2 --- "Diel vertical migration and gut pigment rhythm of marine copepods in Tolo Harbour, Hong Kong" --- p.13, Chapter 2.1 --- Literature Review --- p.13, Chapter 2.2 --- Introduction --- p.21, Chapter 2.3 --- Material and Methods --- p.25, Chapter 2.4 --- Results --- p.31, Chapter 2.5 --- Discussion --- p.66, Chapter 2.6 --- Conclusion --- p.79, Chapter Chapter 3 --- Distribution and biology of marine cladocerans in the coastal waters of southern China --- p.80, Chapter 2.1 --- Literature Review --- p.80, Chapter 2.2 --- Introduction --- p.84, Chapter 2.3 --- Material and Methods --- p.93, Chapter 2.4 --- Results --- p.132, Chapter 2.5 --- Discussion --- p.133, Chapter 2.6 --- Conclusion, References --- p.139, http://library.cuhk.edu.hk/record=b5887729, Use of this resource is governed by the terms and conditions of the Creative Commons “Attribution-NonCommercial-NoDerivatives 4.0 International” License (http://creativecommons.org/licenses/by-nc-nd/4.0/)