We analyzed a large data set of laboratory experiments to examine the effects of cyanobacteria containing or lacking intracellular toxic metabolites and of different morphology on zooplankton population growth rates across multiple genera and species of cladocerans, rotifers and cyanobacteria. Twenty-one of the 29 zooplankton species maintained positive growth rates when fed a diet containing cyanobacteria even though cyanobacteria were a poor food source for half of the zooplankton species tested relative to a diet containing only green algae and/or flagellates. Differences among zooplankton species could not be explained by grazer species body lengths, even when experiments were restricted to those that used only filamentous cyanobacteria. Single-celled cyanobacteria were more detrimental to a larger number of zooplankton species compared to filamentous or chroococcoid colonial cyanobacteria. We also found no clear effect of putative cyanobacterial toxins on the growth of seven zooplankton ...

p,Zooplankton play an important role in the trophic dynamics of coral reef ecosystems. Detailed vertical and temporal distribution and biomass of zooplankton were evaluated at four heights off the bottom and at six times throughout the diel cycle over a coral reef in the Florida Keys (USA). Zooplankton abundance averaged 4396 +/- 1949 SD individuals m(-3), but temporal and spatial distributions varied for individual zooplankton taxa by time of day and by height off the bottom. Copepods comprised 93-96% of the abundance in the samples. Taxon-based zooplankton CHN values paired with abundance data were used to estimate biomass. Average daily biomass ranged from 3.1 to 21.4 mg C m(-3) and differed by both height off the bottom and by time of day. While copepods were the numerically dominant organisms, their contribution to biomass was only 35% of the total zooplankton biomass. Our findings provide important support for the new emerging paradigm of how zooplankton are distributed over ...

Desert springs, which harbor diverse and endemic invertebrate assemblages, are often used as refuge habitats for protected fish species. Additionally, many of these springs have been colonized by invasive fish species. However, the potential impacts of recently established fish populations on invertebrate communities in desert springs have been relatively unexplored. We conducted a mesocosm experiment to assess the impact of both protected and invasive fish on community structure of spring-dwelling invertebrates focusing on zooplankton. Experimental populations of spring zooplankton communities were established and randomly assigned to one of three treatments, (1) invasive western mosquitofish (Gambusia affinis); (2) endangered Mohave tui chub (Siphateles bicolor mohavensis); and (3) fishless control. Final populations of zooplankton and fish were sampled, sorted, identified and counted. The treatment differences of zooplankton communities were analyzed by comparing the densities of six major

A literature synthesis of phytoplankton growth (μ) and grazing (m) rate estimates from dilution experiments reveals that microzooplankton account for most phytoplankton mortality in the oceans, averaging 60-75% of daily phytoplankton production (PP) across a spectrum of open-ocean and coastal systems. For reasonable estimates of gross growth efficiency (GGE=30-40%), such impacts imply that secondary production rates of microzooplankton (MP2°) are typically in the range 21-34% of PP. However, multiple trophic transfers within the microbial community can further enhance total microzooplankton production by an additional third to a half (MPtot=28-55% of PP). These estimates are 2-5 times typical values for bacterial production (10-15% of PP). Thus, in aggregate and on average, microzooplankton consume substantially more (6-7 times) production from phytoplankton than from heterotrophic bacteria. High grazing impacts and relatively high GGEs are consistent with population growth rates for ...

Discussion Our study suggests that local and regional processes interact to produce patterns of species composition and diversity of zooplankton in Kasseb Reservoir. In this system of highly connected reservoirs, Kasseb Reservoir provides the water for the Ghdir El Goulla Reservoir (Sellami et al., 2009). Connections between reservoirs can have positive and negative impacts on zooplankton communities. The Kasseb Reservoir has low diversity (8 zooplankton species). The results of this study suggest that this system is structured according to the species-sorting paradigm (Leibold et al., 2004). Connectivity can promote high community diversity by providing new species from the regional pool, but can also limit local diversity by washing out species, setting up local communities for competitive exclusion, and otherwise providing a disturbance that can offset equilibrium conditions (Cottenie and DeMeester, 2005).. The highest zooplankton densities were found in early September at a depth of 5 m ...

Zooplankton abundance and species diversity in two lakes with different trophic states (Corrientes, Argentina) Abundância e diversidade específica do zooplâncton em dois lagos com estados tróficos diferentes (Corrientes, Argentina) Frutos, SM.1, 2, Poi de Neiff1, 2, ASG. and Neiff, JJ.1 Centro de Ecología Aplicada del Litoral - CONICET, CP 3400, C.C. 291, Corrientes, Argentina e-mail: [email protected]; [email protected] 2 Departamento de Biología, FACENA, Universidad Nacional del Nordeste e-mail: [email protected] Abstract: Aim: In this study, we compare the composition and abundance of zooplankton community between a lake affected by the domestic sewage and in an unaffected lake. We also identified the environmental variables associated with the variation in the most abundant populations and the rotifer species that are indicators of trophic state; Methods: Seventeen zooplankton samples (50 L per sample) were filtered through a plankton net (53 µm) in the limnetic zone of each site. Non ...

Quantitative seasonal studies on gelatinous zooplankton in Norwegian fjords are scarce. We recorded the quantitative composition of the gelatinous zooplankton community in Korsfjord and Fanafjord during 1 yr. Thirty-six species or genera of hydromedusae, 7 species of siphonophores, 4 species of ctenophores and 2 species of scyphomedusae were recorded. Aglantha digitale was numerically dominant in both fjords. A separate video-profiling study on the vertical distribution of fully grown specimens of this species was made in Korsfjord and the adjacent Bjørnafjord. Our data suggest 2 A. digitale generations yr-1, with relatively low importance of the latter generation. The overwintering strategy includes autumn growth to full size and distribution at intermediate depth, mainly between 200 and 300 m. Siphonophores were prominent in the more oceanic Korsfjord, while Fanafjord was characterized by meroplanktonic hydromedusae. More species were recorded from Korsfjord, which may be partly attributed to ...

The abundance and composition of zooplankton down to 3000 m depth was studied in the subtropical and tropical latitudes across the Atlantic, Pacific and Indian Oceans (35 °N–40 °S). Samples were collected from December 2010 to June 2011 during the Malaspina Circumnavigation Expedition. Usually, low abundances were observed with the highest values found in the North Pacific Ocean, Benguela, and off Mauritania, and the lowest in the South Pacific Ocean. No significant differences in abundance and zooplankton composition were found among oceans, with depth being consistently the most important factor affecting their distribution. Each depth strata were inhabited by distinct copepod assemblages, which significantly differed among the strata. The contribution of copepods to the zooplankton community increased with the depth although, as expected, their abundance strongly decreased. Among the copepods, 265 species were identified but 85% were rare and contributed less than 1% in abundance.

Metabolic and stoichiometric theories of ecology have provided broad complementary principles to understand ecosystem processes across different levels of biological organization. We tested several of their cornerstone hypotheses by measuring the nucleic acid (NA) and phosphorus (P) content of crustacean zooplankton species in 22 high mountain lakes (Sierra Nevada and the Pyrenees mountains, Spain). The P-allocation hypothesis (PAH) proposes that the genome size is smaller in cladocerans than in copepods as a result of selection for fast growth towards P-allocation from DNA to RNA under P limitation. Consistent with the PAH, the RNA: DNA ratio was , 8-fold higher in cladocerans than in copepods, although fast-growth cladocerans did not always exhibit higher RNA and lower DNA contents in comparison to slow-growth copepods. We also showed strong associations among growth rate, RNA, and total P content supporting the growth rate hypothesis, which predicts that fast-growing organisms have high P ...

Marine zooplankton form a significant part of the marine ecosystem since they are relatively low on the food chain and they exist in vast quantities. However, little is known of their behavior, how they feed, how they interact or their swimming patterns. To explore some of these issues a three-dimensional imaging sonar was developed to track the movements of these zooplankton in their native environment. The tracking problem requires a high frequency sonar with a fast frame update rate and reasonably high resolutions in three dimensions. It also requires a small array to minimize the proximity effects of the transducer package on the zooplankton behavior, to allow mounting of the transducer array on small remotely operated submersible vehicles and to reduce the cost of the sonar. This led to an array architecture which resolves the target volume of interest into a three-dimensional array of volumetric units that are digitized and stored in computer memory. This digitized array of numbers is then ...

Zooplankton, fish and other marine organisms move between the surface of the oceans and deeper waters every day. Zooplankton typically reside at depths during daytime to avoid predation from visual organisms. At night, zooplankton migrate to the surface to feed on small phytoplankton, and fish and other organisms feeding on zooplankton follow their prey to the surface. This movement is called diel vertical migration and is believed to be the largest natural daily movement of biomass of the planet, only potentially exceeded by human commuters.. During his PhD study at DTU Aqua, Jérôme Pinti has developed a method that can improve our understanding of the optimal vertical migration patterns. The method relies on game theory, where organisms are seen as players trying to optimize their fitness-a measure of how well they are doing-considering the behaviour of all other organisms.. Jérôme Pinti has used the method to model, among others, a whole pelagic community-from mesozooplankton to ...

About my research:. A project in the Daly Zooplankton Ecology Lab focuses on identifying changes to zooplankton ecology relative to the Deepwater Horizon (DWH) oil spill. I will be comparing historic pre-spill samples collected by the National Oceanic and Atmospheric Administration to post-spill samples collected by researchers here at USF. My research will establish a baseline of the natural spatial, seasonal, and interannual variation in zooplankton community structure prior to the DWH oil spill and subsequently compare it with post DWH zooplankton data. To process samples, our lab will be using a revolutionary piece of equipment in the zooplankton research field: Hydroptic Zooscan digital imaging system. The Zooscan overcomes traditionally time-consuming and difficult taxonomic techniques that have previously limited large-scale zooplankton analyses. I hypothesize that the DWH oil spill resulted in a significant shift in zooplankton abundance, distribution, and composition in the northeast ...

Station ALOHA is located in the North Pacific Subtropical Gyre 60 miles off of Oahu. Subtropical gyres are known to have a high diversity of zooplankton because of the low nutrients available in this region. High-nutrient sub-polar gyres, contrast with sub-tropical regions, as their zooplankton diversity is low due to increased biomass and intense competition. However, recovery of the MOCNESS and ring nets at Station ALOHA have provided a wide variety of zooplankton for our student scientists on board. We have been working hard all day to obtain information on the abundance and types of zooplankton found, requiring many hours of sorting through the cod ends of the nets (baskets that collect the seawater and zooplankton). Once collected, scientists must filter out the zooplankton by size and identify the species using microscopes. Some of the desired zooplankton species like nauplii (baby copepods) are so tiny that they have to be sorted with tweezers under a microscope. This is a tedious and ...

Al-Mutairi, H. and Landry, M. R.: Active export of carbon and nitrogen at station ALOHA by diel migrant zooplankton, Deep-Sea Res. Pt. II, 48, 2083-2103, https://doi.org/10.1016/S0967-0645(00)00174-0, 2001. Andersen, V., Devey, C., Gubanova, A., Picheral, M., Melnikov, V., Tsarin, S., and Prieur, L.: Vertical distributions of zooplankton across the Almeria-Oran frontal zone (Mediterranean Sea), J. Plankton Res., 26, 275-293, https://doi.org/10.1093/plankt/fbh036, 2004. Antezana, T.: Vertical distribution and diel migration of Euphausia mucronata in the oxygen minimum layer of the Humboldt Current, Oceanogr. East. Pacific II, 2, 13-28, 2002. Antezana, T.: Species-specific patterns of diel migration into the Oxygen Minimum Zone by euphausiids in the Humboldt Current Ecosystem, Prog. Oceanogr., 83, 228-236, https://doi.org/10.1016/j.pocean.2009.07.039, 2009. Antezana, T.: Euphausia mucronata: A keystone herbivore and prey of the Humboldt Current System, Deep-Sea Res. Pt. II, 57, 652-662, ...

Ecology, Evolutionary Biology and Behavior Program // Department of Fisheries and Wildlife. Topics: Community Ecology, Trophic interactions, Non-consumptive predator effects, Animal Behavior, Phenotypic Plasticity. We seek applicants who are interested in studying community and aquatic ecology starting in Fall 2012. We currently have funding for students to join a research effort examining non-consumptive effects (also called trait-mediated effects) of predators on zooplankton communities in Michigan ponds. Potential projects include examining predator-induced effects on zooplankton phenotype (including behavior) and how these induced effects influence zooplankton population and community dynamics. While particular PhD projects are flexible within the scope of the overall project, the positions could include integration of field, laboratory and ecological modeling. One of the positions will be given to a student interested in their research including ecological theory /modeling. Collaborators ...

Burkill, Peter (2004): Biomass and abundance of microzooplankton and nanoflagellates at bottle station A6/1. PANGAEA, https://doi.org/10.1594/PANGAEA.135385

Our research interests are in zooplankton ecology and physiology, coastal and deep-sea food webs, nutrient cycling, and marine detritus or marine snow. Much of our current focus is on how zooplankton community structure affects flux of organic material and cycling of nutrients in the sea.. Our laboratory is involved in a number of projects with this theme, including the. ...

The report describes results of studies conducted to obtain data to assess the effects of waste disposal on the marine environment of the New York Bight. The report concerns zooplankton studies including distribution, seasonal occurrence and vertical migration of zooplankton populations in the dumping grounds. (Author)(*MARINE BIOLOGY

We developed new perspectives to identify important questions and to propose approaches for future research on marine food web lipids. They were related to (i) structure and function of lipids, (ii) lipid changes during critical life phases, (iii) trophic marker lipids, and (iv) potential impact of climate change. The first addresses the role of lipids in membranes, storage lipids, and buoyancy with the following key question: How are the properties of membranes and deposits affected by the various types of lipids? The second deals with the importance of various types of lipids during reproduction, development, and resting phases and addresses the role of the different storage lipids during growth and dormancy. The third relates to trophic marker lipids, which are an important tool to follow lipid and energy transfer through the food web. The central question is how can fatty acids be used to identify and quantify food web relationships? With the fourth, hypotheses are presented on effects of ...

To evaluate the effects of different anthropogenic activities on zooplankton and the pelagic ecosystem, we conducted seasonal cruises in 2010 to assess spatial heterogeneity among the mesozooplankton communities of Xiangshan Bay, a subtropical semi-enclosed bay in China. The evaluation included five different areas: a kelp farm, an oyster farm, a fish farm, the thermal discharge area of a power plant, and an artificial reef, and we aimed to identify whether anthropogenic activities dominated spatial variation in the mesozooplankton communities. The results demonstrated clear spatial heterogeneity among the mesozooplankton communities of the studied areas, dominantly driven by natural hydrographic properties, except in the area near the thermal discharge outlet of the power station. In the outlet area, thermal shock caused by the discharge influenced the mesozooplankton community by decreasing abundance and biomass throughout the four seasons, even causing a shift in the dominant species near the ...

Ecological consequences of global warming include shifts of species ranges toward higher altitudes and latitudes as well as temporal shifts in phenology and life-cycle events. Evidence is accumulating that increasing temperature is also linked to reduced body size of ectotherms. While temperature can act directly on body size, it may also act indirectly by affecting the timing of life-cycle events and the resulting population age and size structure, especially in seasonal environments. Population structure may, in turn, be influenced by temperature-driven changes in resource availability. In a field mesocosm experiment, we investigated how water temperature and mixed surface layer depth (a temperature-dependent determinant of light availability to phytoplankton) affected population dynamics, population age and size structure, and individual size at stage (size at first reproduction) of Daphnia hyalina during and after a phytoplankton spring bloom. Mixed layer depth was inversely related to the ...

ePIC (electronic Publication Information Center) is the official repository for publications and presentations of Alfred Wegener Institute for Polar and Marine Research (AWI)

Detection of population genetic structure of zooplankton at medium-to-small spatial scales in the absence of physical barriers has remained challenging and controversial. The large population sizes and high rates of gene flow characteristic of zooplankton have made resolution of geographical differentiation very difficult, especially when using few genetic markers and assuming equilibrium conditions. Next-generation sequencing now allows simultaneous sampling of hundreds to thousands of genetic markers; new analytical approaches allow studies under nonequilibrium conditions and directional migration. Samples of the North Atlantic Ocean planktonic copepod, Centropages typicus, were analysed using restriction site-associated DNA (RAD) sequencing on a PROTON platform. Although prior studies revealed no genetic differentiation of populations across the geographical range of the species, analysis of RAD tags showed significant structure across the North Atlantic Ocean. We also compared the likelihood ...

A concentrated blend of marine zooplankton designed to provide the essential fatty acids, proteins, vitamins, amino acids, & natural carotenoids needed for coral growth. Provides a more bioavailable source of pigmentation.

Current fauna, biomass and distribution on zooplankton in the upper water of the Yinluan Project are investigated and studied. A biodiversity Index analysis is performed. Based on the present study and referring to the historic investigated data and the information from the studies on allied domestic water bodies, an ecological and environmental status of the investigated area is assessed and evaluated. The research result suggests that the water quality of the area can be delimited to poor to mesotrophic type. But more attention should be paid as the eutrophication tendency caused by box aquaculture in Panjiakou and Daheiting Reservoirs.

Using common garden experiments and a comparative field study, we have shown that the strong effects of life-history differences among alewife populations on zooplankton communities have propagated across the food web to influence the phenotype and fitness of a competing species. We found that bluegill from different lake types differed in (i) growth rates when exposed to small- or large-bodied prey, (ii) prey size selectivity and (iii) gill raker morphology. Our results revealed clear divergence in foraging traits between bluegill from landlocked and no-alewife lakes, but only weak divergence in bluegill between anadromous and no-alewife lakes. Consistent predation by landlocked alewife shapes the zooplankton community [7] such that it produces strong selection for traits that increase foraging performance on small-bodied zooplankton [16]. Consequently, we found bluegill from replicated landlocked lakes to be better adapted to feeding on small-bodied prey; they were less selective for large ...

Inhabits reef channels or along slopes that are subject to strong currents (Ref. 48637). Occur in current-swept seaward coral reefs. Usually form aggregations and feed on zooplankton as well as sponges (Ref. 9770). Juveniles associated with isolated patches of rubble or crevices with proper-sized shelter holes (Ref. 1602). Oviparous (Ref. 205). Form large schools to feed on zooplankton (Ref. 48637). Also taken by drive-in nets (Ref. 9770). Marketed fresh or dried-salted. Minimum depth reported taken from Ref. 30874. Popular aquarium fish (Ref. 37816). ...

At the Institute of Oceanography and Fisheries, planktonology research has a long tradition, dating since the very beginnings of the Institute activities. Working in the lab combines research in ecology and phytoplankton and zooplankton taxology, and researching primary production processes. Taxonomy research is mostly focused on microzooplankton, mezozooplankton and microphytoplankton, while in the ecological research most of the attention is on the research of phytoplankton and zooplankton community changes created under the influence of anthropogenic activities and climate changes. In this research of great help is long-term data (phytoplankton, zooplankton, primary production, chlorophyll / a /), which represent a special value of this laboratory and the Institute itself.. ...

Lakes are important global ecosystems and many of them are nutrient-poor (unproductive). Especially in northern boreal latitudes, lakes may be heavily subsidized by terrestrial organic material (t-OM) from peat layers in the catchment. Thus, in addition to heterotrophic bacteria and phytoplankton, zooplankton may also use the particulate fraction of peat layer t-OM (t-POM) as a potential food source in those systems. Inputs of t-OM in northern latitudes are anticipated to increase in the future due to increasing precipitation and temperature. As t-OM is a good substrate for bacterial growth and as bacteria can often outcompete phytoplankton for inorganic nutrients, the proportions of heterotrophic bacteria and phytoplankton are expected to change in unproductive lakes. This may have pronounced impacts on zooplankton population dynamics.. The aim of my thesis was to investigate how changes in food quality and quantity will affect metazoan zooplankton performance in unproductive lakes. Three ...

Zooplankton are key members of marine ecosystems, but the biological and physical factors governing their distribution and aggregation are not fully understood, especially at the continental shelf break and margins of the deep basins of the shelf. Euphausiids are an important group of crustacean zooplankton in North Atlantic pelagic food webs and represent an interesting model species for the study of zooplankton aggregation due to their strong swimming capabilities and active aggregative behaviors. This project will address the hypotheses that the formation and variability of euphausiid aggregations along the northern flank of Georges Bank and the southern portion of the Gulf of Maine during fall relate to the interaction of physical concentration mechanisms with local topography and with plasticity in diel vertical migration and active aggregative behaviors, and that this plasticity arises from variability in food availability and predation by herring. These hypotheses will be addressed ...

The benthic macroinvertebrates and the zooplankton of the shallow (,1.5 m deep) sandy middle regions of the Peel-Harvey Estuary and of the nearby Swan Estuary were sampled seasonally between the winters of 1986 and 1987. Measurements were also taken of the environmental variables in the benthos and in the water column.. In comparison with the Swan Estuary, the Peel-Harvey Estuary is highly nutrient enriched and is not as well flushed. As a consequence, the water in the basins of the Peel-Harvey experience large seasonal blooms of the blue-green alga Nodularia spumigena and massive growths of benthic and drifting green algae. The first led to marked seasonal declines in redox values, secchi depths and nocturnal dissolved oxygen and, together with the decomposition of the macroalgae, resulted in a marked increase in particulate organic matter in the sediments.. The following comparisons between the benthic invertebrate fauna in the Peel- Harvey with that of the Swan Estuary are consistent with the ...

Abstract. In a changing ocean there is a critical need to understand global biogeochemical cycling, particularly regarding carbon. We have made strides in understanding upper ocean dynamics, but the deep ocean interior (, 1000 m) is still largely unknown, despite representing the overwhelming majority of Earths biosphere. Here we present a method for estimating deep-pelagic zooplankton biomass on an ocean-basin scale. We have made several new discoveries about the Atlantic, which likely apply to the world ocean. First, multivariate analysis showed that depth and Chl were the basic factors affecting the wet biomass of the main plankton groups. Wet biomass of all major groups was significantly correlated with Chl. Second, zooplankton biomass in the upper bathypelagic domain is higher than expected. Third, the majority of this biomass comprises macroplanktonic shrimps, which have been historically underestimated. These findings, coupled with recent findings of increased global deep-pelagic fish ...

The present study uses bioenergetics modeling to estimate the annual consumption of the main zooplankton groups by some of the most commercially important planktivorous fish stocks in the Northeast Atlantic, namely Norwegian spring-spawning (NSS) herring (Clupea harengus), blue whiting (Micromesistius poutassou) and NEA mackerel (Scomber scombrus). The data was obtained from scientific surveys in the main feeding area (Norwegian Sea) in the period 2005-2010. By incorporating novel information about ambient temperature, seasonal growth and changes in the diet from stomach content analyses, annual consumption of the different zooplankton groups by pelagic fish is estimated. The present study estimates higher consumption estimates than previous studies for the three species and suggests that fish might have a greater impact on the zooplankton community as foragers. This way, NEA mackerel, showing the highest daily consumption rates, and NSS herring, annually consume around 10 times their total ...

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Friday, January 18, 2013, 05:20 (GMT + 9) A new study provides unprecedented evidence of viral infections in copepods, or tiny marine crustaceans. Viruses could account for part of the up to 35 per cent of the zooplanktons mortalities, whose causes are currently unknown but suspected to be harmful algae, environmental stressors, parasites and diseases. Researchers used genomic techniques to support the hypothesis that viral infections are a major cause of copepod deaths.. The study was published in the Proceedings of the National Academies of Science.. This is the first evidence of viruses in marine zooplankton, said Ian Hewson, Cornell University assistant professor of microbiology and senior author of the paper. Copepods are critical in oceanic food webs and ocean carbon cycling, which helps regulate the Earths climate. They also consume most of the oceans phytoplankton, which seize about half of the carbon dioxide pulled from the atmosphere and fixed in plant cells. As copepods defecate ...

Maha devaraya prabhu is the union home minister and his daughter is aishwarya ileana. Among freshwater and marine zooplankton, whether single-celled or multi-cellular, predatory grazing on phytoplankton and smaller zooplankton is common, found in many species of nanoflagellates, ciliates, rotifers, a diverse range of meroplankton animal larvae, two groups of crustaceans, namely copepods and cladocerans. Yeah, retrieve mind is one that is needed bearing in mind reading the book. Kasumi december 20, pm gosh download ebooks for android the ending was sad with what he wrote in his manuscript. Do you call everyone that fails after some time a failure? All of this may seem very idealistic, and in some cases its where to read books for free online just that. Astigmatism can be treated in a host of ways including corrective contact lenses, eyeglasses, laser surgery as well as other refractive surgery procedures. Limited edition, available on our store in a few days. Delays to air mail free ebooks ...

Positive associations between temperature and recruitment success of cod, haddock and herring in the area studied are well documented, but the causal basis has remained elusive (Ottersen et al. 2004). Disentangling the roles of temperature and zooplankton has been particularly difficult because the temperature index used in most studies (TKOLA) has been considered as an indicator of both temperature and zooplankton availability in the study system (Ottersen & Sundby 1995; Ottersen & Loeng 2000), and because multi-annual zooplankton data have largely been lacking (but see Ellertsen et al. 1989). Several non-exclusive mechanisms have been suggested to explain the temperature-recruitment associations, including physiological effects of temperature on growth (Ottersen & Loeng 2000), increased on-shelf advection of copepods in warm years (Sundby 2000) and a better spatio-temporal match between the fish larvae and their zooplanktonic food during warm years (Ellertsen et al. 1989; Fossum 1996). Our ...

Get an answer for What is the difference between phytoplankton and zooplankton?Classify the 7 protists in these 2 categories. and find homework help for other Science questions at eNotes

Interactions between organisms and complex flow fields are of significant consequence to many ecological processes (e.g. predator-prey interactions, swimming behavior, spatial dispersion and distribution, diel migration). Thus, turbulence-organism interactions have received much recent attention (e.g. Prairie et al., 2012; Guasto et al., 2012; Durham et al., 2013; Jumars et al., 2009; Yamazaki and Squires, 1996). Quantifying turbulent flow fields with high spatial and temporal resolution, and relating them to the behavior and distributions of organisms, e.g. zooplankton, is critical for advancing our understanding. However, obtaining such data is challenging. First, both turbulent flows and planktonic motion are unsteady and three-dimensional, requiring a time-resolved, volumetric measurement system; second, plankton can propel themselves relative to the surrounding fluid leading to local differences in fluid and organism velocity; and third, many planktonic organisms have ...

87000 by 2015, among which over 4,800 samples have been analyzed at species level. Although no online access is available, those data are recorded following the international standard (Darwin Core) format. ​. Using those species level data, we have studied how ecosystem structures in the western North Pacific changed responding to climatic forcing, in particular, the North Pacific Decadal Oscillation (PDO). The scientific outcome includes phenological change and latitudinal shift of dominant copepods, Neocalanus species, which were driven by the decadal warm-cool cycle related to PDO. As mentioned above, one of the recent trends in the retrospective study is basin to global scale synthesis of long-term ecosystem changes. We have conducted collaborative studies with international counterparts, and participated in some international projects aiming for global comparison of long-term zooplankton variation. Those collaborative researches revealed, for example, the seesaw pattern in its decadal ...

University of British Columbia researchers have identified a small virus that attacks another virus more than 100 times its own size, rescuing the infected zooplankton from certain death. The discovery may provide clues to the evolutionary origin of some jumping genes found in other organisms. The study, by UBC marine microbiologist Dr. Curtis Suttle and Ph.D. student Matthias Fischer, was published online March 3, 2011, in Science Express. It describes the marine virus Mavirus and its interaction with marine zooplankton Cafeteria roenbergenesis and CroV, the worlds largest marine virus. Its a microbial version of the David and Goliah story where, after infecting Cafeteria roenbergeneis, Mavirus protects it against infection by CroV, while ensuring its own survival, said Dr. Suttle. Viruses rely on host cells to replicate; in the case of Mavirus, its host is another virus, making it only the second known virophage. It needs CroV to replicate, and in the process suppresses the propagation of ...

Kelly Benoit-Bird is a marine biologist who uses sophisticated acoustic engineering techniques to explore the previously invisible behavior of ocean creatures at scales ranging from swarms distributed over many cubic kilometers to individual predators. The food web of ocean surface waters begins with microscopic creatures that serve as the source of food for tiny organisms (zooplankton) just large enough to generate an acoustic signature. Although zooplankton drift in response to ocean currents, Benoit-Bird has shown that they use their modest locomotive capacity to form swarms with distinct three-dimensional structures that change with feeding conditions. Using multi-frequency acoustic backscattering, she has been able to reconstruct the feeding patterns of swimming predators of zooplankton (known as nekton) as they first pass downward through a layer of zooplankton, then reverse course and pass through upward. Having precise data about the horizontal and vertical distribution of oceanic food ...

Biomass, proximate composition, organic carbon and calorie content of assorted zooplankton from the surface waters were studied. Day and night stations revealed significant difference in biomass (displacement volume, dry wt and organic carbon) whereas at coastal and oceanic stations irrespective of day and night the difference was significant only in dry wt values. Protein and organic carbon content peaked at 14-degrees-16-degrees-N. Average calorific content was 4.05 kcal.g-1 dry wt. High lipid content at 12-degrees-14-degrees-N correlated with maximum chl-a ...

The effects of increasing fishing pressure in combination with temperature increases in the Nordic and Barents Seas have been evaluated using an end-to-end model for the area forced by a downscaled RCP 4.5 climate scenario. The scenarios that have been applied have used four different fractions of fisheries mortality at maximum sustainable yield (Fmsy); 0.6, 0.8, 1.0 and 1.1 × Fmsy. As it is highly likely that more ecosystem components will be harvested in the future, the four scenarios have been repeated with fishing on a larger number of ecosystem components, including harvesting of lower trophic levels (mesozooplankton and mesopelagic fish). The zooplankton biomass had an increasing trend, regardless of the increase in fishing pressure on their predators. However, when introducing harvest on the lower trophic levels, this increase was no longer evident. When harvesting more components, the negative response in biomass of pelagic and demersal fish to increasing harvest became more prominent,

Zooplankton dormancy forms in two environments of the upper Paraná River floodplain (Brazil) Formas de dormência do zooplâncton em dois ambientes da planície de inundação do alto Rio Paraná (Brasil) Palazzo,

Sigma-Aldrich offers abstracts and full-text articles by [Peter J Lavrentyev, Gayantonia Franzè, James J Pierson, Diane K Stoecker].

2017 John Wiley & Sons Ltd Gelatinous zooplankton are a large component of the animal biomass in all marine environments, but are considered to be uncommon in the diet of most marine top predators. However, the diets of key predator groups like seabirds have conventionally been assessed from stomach content analyses, which cannot detect most gelatinous prey. As marine top predators are used to identify changes in the overall species composition of marine ecosystems, such biases in dietary assessment may impact our detection of important ecosystem regime shifts. We investigated albatross diet using DNA metabarcoding of scats to assess the prevalence of gelatinous zooplankton consumption by two albatross species, one of which is used as an indicator species for ecosystem monitoring. Black-browed and Campbell albatross scats were collected from eight breeding colonies covering the circumpolar range of these birds over two consecutive breeding seasons. Fish was the main dietary item at most sites; ...

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There are a lot of factors that influence the composition and abundance of zooplankton communities which are namely physical, chemical and biological. Factors recognised mostly are temperature, pH, and availability of food, these act simultaneously causing it to interact to different degrees resulting the structure of zooplanktons to be in a variety. Temperature controls the reproductive rate, population size and metabolism of the species (Edmondson, 1965) while in tropical regions, precipitation and wind are the physical factors which are significant in affecting the composition of zooplanktons (Matsumara-Tundinsi & Noguiera, 1996). Predation by fish may affect its structure as well in accordance with the fish feeding mode: selective feeders, differential capture of organisms, tendency to eliminate large species which are replaced by less vulnerable forms (Brooks & Dodson, 1965). The diversity of species may be lesser sometimes but single species may be superior over other groups in terms of ...