Thesis (M.Sc.)--Memorial University of Newfoundland, 2003. / Includes bibliographical references. Also available online.

No description available.

In estuaries, like the Indian River Lagoon, mesozooplankton have a vital role in the food web by connecting trophic levels. In this study, mesozooplankton abundance and species composition were monitored weekly on the incoming and outgoing tides from September 2006 to May 2009. For the incoming tide, the mean abundance was 2298.2 mesozooplankton/m3 (+/-325.2), and for the outgoing tide the mean abundance was 1180.0 mesozooplankton/m3 (+/-153.1). The mesozooplankton abundance on the incoming tide was significantly greater than on the outgoing tide. The most abundant type of mesozooplankton was the copepod Acartia tonsa, representing 35.0% and 52.1% of the individuals on the incoming and outgoing tides respectively. Mesozooplankton abundance values were compared with environmental data obtained from the South Florida Water Management District. The strongest positive correlation was found between chlorophyll a concentrations and A. tonsa abundance, likely due to phytoplankton being the primary food source for A. tonsa. / by Miranda Hoover Kerr. / Thesis (M.S.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web.

Ng, Ka Yan. / "November 2009." / Thesis (M.Phil.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 329-399). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract (English) --- p.iv / Abstract (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

The hydrodynamic disturbances generated by two types of free-swimming, marine zooplankton were quantified experimentally in the laboratory with a novel, infrared Particle Image Velocimetry (PIV) system. The study consisted of three main parts: (1) the flow fields of free-swimming and tethered Euchaeta antarctica were compared to determine the effects of tethering, (2) three species of copepods (Euchaeta rimana, Euchaeta elongata, and Euchaeta antarctica) that live in seawater in a range of temperatures (23 ºC - 0 ºC) and a corresponding range of fluid viscosity (0.97 - 1.88 mm2 s-1) were analyzed experimentally and with a computational fluid dynamics model (FLUENT) to assess the effect of size and fluid viscosity on the flow fields, (3) the flow fields were collected for individuals of two species of euphausiids (Euphausia pacifica and Euphausia superba) to compare the effect of size and Reynolds number on propulsion and the spatial extent of the flow disturbance. In addition to the measured flow fields around solitary krill, flow fields were collected around small, coordinated groups of E. superba to examine group sensory cues through hydrodynamics. In the first part of this investigation, it was determined that tethering zooplankton during data collection resulted in flow fields with increased asymmetry and larger spatial extent due to the unbalanced force applied to the fluid by the tether. In response to these findings, only flow fields collected for free-swimming organisms were used in the subsequent studies. In the second part of the study, the increase in viscosity between subtropical and temperate fluid environments in conjunction with increased size and species-specific swimming speeds resulted in similar Reynolds numbers among E. elongata and E. rimana (in both cruising and escaping modes). During cruising (Re ~10), the spatial extent of the copepod hydrodynamic disturbances and propulsion costs were similar between species. In the case of fluid distrubances of escape (Re ~ 100), the spatial extent and energetic cost were larger for the larger species ( E. elongata). In the third part of the study, the hydrodynamic disturbance produced by E. superba (larger krill species) was found to be longer in horizontal spatial extent and at scales more appropriate for communication within schools than the hydrodynamic disturbance produced by E. pacifica. However, the sensory cue in coordinated groups of krill was complicated by the interaction of multiple flow disturbance fields, which suggests that hydrodynamic cues between krill in groups are restricted to small distances. The energetic cost of propulsion was ten times greater for the larger species of krill, and energetic expenditure did not appear to decrease for krill swimming in coordinated groups.

A biological front at the mouth of Saanich Inlet results in higher rates of primary productivity at the inlet mouth relative to the head creating a gradient that could influence zooplankton distribution. A shallow sill (75m) at the inlet mouth restricts circulation below sill depth, isolating the deep basin for much of the year. Anoxia develops in the isolated basin and the depth of the anoxic layer changes during the year. During the day, pelagic zooplankton form a deep scattering layer. Between April 2005 and March 2006. I conducted monthly 200kHz acoustic surveys between the mouth and head of Saanich Inlet to test the hypothesis that zooplankton density was greater near the mouth relative to the head. I was also interested in how changing anoxic layer depth affected the distribution of the deep scattering layer. I found that zooplankton density followed a headward gradient in the spring and summer. with the highest densities near the mouth. Zooplankton density was higher near the mouth or the mid-inlet relative to the head in 75% of transects. I did not observe a zooplankton density gradient during the winter. Zooplankton distribution was affected by dissolved oxygen concentration. Deep scattering layer depth was significantly correlated with the depth of the anoxic layer and vertical compression of the deep scattering layer increased as the anoxic layer moved upwards. When the depth of the anoxic layer was less than 90 meters. zooplankton were nearly absent. Vertical migration of the deep scattering layer to surface waters at night has been well documented. but zooplankton migration patterns in the shallow waters of Saanich Inlet have not been described. I used 200kHz acoustic data collected by the VENUS observatory (96m) and an autonomous acoustic system deployed at a shallow site (62m) in Patricia Bay to study zooplankton migration patterns. Horizontal movement of the deep scattering layer over shallow depths following vertical migration was infrequent. Over 41 days of observation at the shallow site. I only observed deep scattering layer zooplankton on 12 days. At the shallow site. night-time volume backscatter was dominated by the emergence of benthic zooplankton. The movement of these scatterers into the water column at night resulted in a 14-fold increase in volume backscatter over daytime values. I observed this emergence pattern at both sites. which represents an important component of benthic-pelagic coupling in Saanich Inlet. In contrast to the deer scattering layer. which migrated to the surface each night, emergent zooplankton remained within 30-40 meters of the seafloor and did not ascend into surface waters.

Thesis (Ph.D.)--University of Western Australia, 2006.

Thesis (M.Sc. (Ichthyology & Fisheries Science)) - Rhodes University, 2009.

Orientador: Teodoro Vaske-Junior / Resumo: As áreas costeiras de baixa profundidade, como zonas de arrebentação de praias arenosas são pouco estudadas quando comparadas a outros ecossistemas costeiros. No entanto, são consideradas de grande importância ecológica, pois abrigam alta diversidade de organismos que se alimentam, reproduzem e buscam na região proteção contra predadores. A falta de estudos deve-se principalmente à alta hidrodinâmica existente, sendo muitas vezes difícil de amostrar, principalmente no período noturno. Este estudo analisou a variação temporal e nictemeral da fauna zooplanctônica existente na zona de arrebentação da Praia da Aviação que trata-se de uma praia densamente habitada localizada no município de Praia Grande na costa central do estado de São Paulo. Os organismos foram coletados com rede de plâncton através de arrastos horizontal, superficial e perpendicular à praia em profundidade de 1m. Dados de temperatura e salinidade também foram obtidos juntamente com observações visuais do estado de agitação do mar, vento local e nebulosidade. Este processo ocorreu bimensalmente entre Junho de 2013 e Abril de 2015 durante os períodos diurno e noturno, visando avaliar a variação na composição zooplanctônica e sua relação com as migrações verticais. O zooplâncton da praia analisada foi representado por 116 táxons, englobando organismos holoplanctônicos, meroplanctônicos, bentônicos (presentes na coluna d'água devido à alta turbulência) e bentoplanctônicos (organismos que realizam migração vertical)... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Low depth coastal areas, such as surf zones at the sand beaches, are poorly studied when compared to other coastal ecosystems. However, they are considered of great ecological importance, because they shelter a high diversity of organisms that feed, reproduce and seek protection in the region against predators. The lack of studies is mainly due to the existing high hydrodynamics, and is often difficult to sample, especially at night. This study analyzed the temporal and nictemeral variation of the zooplankton existing in the surf zone of Praia da Aviação, a densely populated beach, located in the Praia Grande city, on the central coast of the State of São Paulo. The organisms were collected with plankton net through horizontal trawls, superficial and perpendicular to the beach in depth of 1m. Temperature and salinity data were also obtained along with visual observations of the state of sea agitation, local wind and cloudiness. This process occurred bimonthly between June 2013 and April 2015 during the day and night periods, With the objective of evaluating the variation in zooplankton composition and its relationship with vertical migrations. The zooplankton of the beach was represented by 116 taxa, including holoplanktonic, meroplanktonic, benthic organisms (present in the water column due to the high turbulence) and bentoplanktonic organisms (organisms that perform vertical migration). The faunal composition was quite diverse and, throughout the study, there was little variation in the diversity between the sampling periods as well as discrete seasonal variation. The total abundance of planktonic organisms captured in the daytime ranged from 384 to 14,746 org.m-³ (4.153.1 ± 5.766 org.m-³) and, during the night from 504 to 67,269 org.m-³ (7,845.3 Ñ 18,844 org.m-³). The zooplankton community demonstrated a significant difference (p <0.000), in terms of abundance, between the holoplankton... (Complete abstract electronic access below) / Mestre

This thesis presents the first intensive community-level investigation of the mesozooplankton from a biogeographical transition zone estuary. The Mgazana Estuary is located along a rural, semi-undeveloped part of South Africa’s east coast, believed to represent a transition zone between the subtropical and warm-temperate biogeographical zones. The research represented in this thesis involves data collected over a five year period between 2002 and 2006, with additional data collection made in 2008. The study focussed on five areas of investigation, the first of which investigated the physico-chemical dynamics of the Mgazana Estuary. The Mgazana Estuary exhibited marked vertical, horizontal and regional structures in the hydrological environment. Prominent vertical and horizontal stratification characterised summer months. A substantial turbidity front was observed in the lower estuary during summer and winter. The upper estuary was marked by considerable variation in multiple variables but especially salinity. These structures appeared to have shifted in position over the horizontal plane, which was attributed to variation in freshwater flow. The second study focused on the spatial dynamics of mesozooplankton in the Mgazana Estuary. The zooplankton was rich and in terms of composition typical of mangrove systems. The Copepoda were dominant, numerically and in terms of taxonomic representation. Calanoids Acartiella natalensis and Pseudodiaptomus hessei characterised middle and upper reaches in summer and mostly upper reaches in winter. On community level, a highly structured assemblage arrangement was observed during summer and winter months. These trends were further scrutinised under the theoretical framework of ecological boundaries. In so doing, an agreeable spatial association emerged between specific assemblages and their environments. These trends were concluded to reflect ecoclinal as well as ecotonal properties, the latter describing interactions over narrow spatial bands of marked changes in turbidity. The third study investigated flooding events as short-lived extreme meteorological events and the influence on zooplankton. Within this regard, second-stage multivariate statistics was used to assess year-to-year variability in assemblage structures on whole-system and regional scales. The impact of two major flooding events that flushed the estuary some days prior to sampling could clearly be elucidated. Flooding emerged as a significant source of inter-annual variability in the zooplankton of the Mgazana Estuary. Second-stage multivariate analysis proved to be an effective analytical strategy for investigating inter-annual variability in species assemblage structures. Results from the preceding study prompted a detailed investigation into the spatio-temporal dynamics of Acartiella natalensis, the most important zooplankton species of the system aimed at elucidating flood responses. Acartiella natalensis showed indication of temporal arrest in association with flooding events in a similar fashion as is observed in seasonal variation trends in estuaries towards its geographical distribution limit south of the study area. It was concluded that A. natalensis was severely affected by floods and the possibility exist for entrainment of entire populations from the estuary during flooding events. The final study tested the hypothesis of post-flood propagation from a resting egg bank in the sediments of the Mgazana Estuary. Preliminary data revealed that numerous eggs were present in the sediments. Nauplii hatched from eggs under laboratory conditions were identified as belonging to the family Acartiidae. The preliminary mode of diapause is presented as a schematic model, emphasising the role of freshwater flow and specific environmental variables. This was the first discovery of resting eggs from a subtropical estuary from South Africa. It is hoped that the findings of this study would give rise to new research initiatives investigating the importance of resting stages in estuarine and coastal Copepoda species and the role such reproductive strategies may play in estuarine functioning.