Journal articles on the topic 'Community structure; algal feeding; zooplankton'
To see the other types of publications on this topic, follow the link: Community structure; algal feeding; zooplankton.
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Community structure; algal feeding; zooplankton.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Drenner, Ray W., Stephen T. Threlkeld, and Michael D. McCracken. "Experimental Analysis of the Direct and indirect Effects of an Omnivorous Filter-Feeding Clupeid on Plankton Community Structure." Canadian Journal of Fisheries and Aquatic Sciences 43, no. 10 (October 1, 1986): 1935–45. http://dx.doi.org/10.1139/f86-239.
Full textAbstract:
In laboratory trials, feeding rates of an omnivorous filter-feeding clupeid, Dorosoma cepedianum, increased as a function of particle size, with maximal rates on microspheres, spherical algae, and Zooplankton >40 μm; it did not efficiently feed on filamentous Anabaena flos-aquae. To examine the community level impacts of Dorosoma, we conducted four seasonal outdoor tank experiments of cross-classified design involving two or three densities of Dorosoma and two densities of the zooplanktivorous atherinid fish, Menidia beryllina. We attempted to discriminate between the direct and indirect effects of Dorosoma on phytoplankton by using Menidia to produce indirect effects on phytoplankton by suppressing Zooplankton. Experiments began in November, March, June, and September and lasted for 45–53 d. Dorosoma suppressed most Zooplankton in at least one experiment and enhanced algal standing crops in all four experiments, as indicated by increased algal chlorophyll fluorescence, turbidity, Coulter counts and microscopic algal counts, and decreased Secchi depths. Because in three out of four experiments Menidia suppressed Zooplankton biomass to a greater extent than Dorosoma without enhancing phytoplankton, we reject the hypothesis that the enhancement of phytoplankton by Dorosoma was an indirect effect of Zooplankton biomass suppression.
2
Nobili, R., C. Robinson, E. Buitenhuis, and C. Castellani. "Food quality regulates the metabolism and reproduction of <i>Temora longicornis</i>." Biogeosciences Discussions 10, no. 2 (February 21, 2013): 3203–39. http://dx.doi.org/10.5194/bgd-10-3203-2013.
Full textAbstract:
Abstract. A laboratory study was undertaken to determine the effect of food quality on feeding, respiration, reproduction and the resulting carbon budget of Temora longicornis. The stoichiometric ratios N : P, C : N and C : P of Rhodomonas salina were used as indicators of food quality. R. salina was grown in media with different inorganic nutrient concentrations to produce food for T. longicornis with particulate organic N : P ratios ranging from 10 : 1 to 23 : 1. Feeding rate was not affected by food quality. Maximum respiration (R), egg production rate (EPR), assimilation efficiency (AE), gross growth efficiency (GGE) and metabolic increment (MI) occurred when T. longicornis was fed on phytoplankton with a food quality of 16N : 1P. EPR, GGE and AE also decreased with decreasing C : N ratio and the energy required to produce eggs (CoE) decreased with decreasing N : P ratio, indicative of nitrogen-dependent production. These data suggest that an algal composition of 16N : 1P defines the Threshold Elemental Ratio (TER) and is the optimum diet for T. longicornis. The variations in metabolic rates and the resulting carbon budget are proportional to the quality of food ingested. GGE was negatively affected at dietary ratios above and below 16N : 1P, which in the natural environment could lead to a decline in species biomass with detrimental consequences for fisheries and carbon export. Field data show that phytoplankton organic N : P ratios can change on decadal timescales, and that an increase in the food N : P ratio can co-occur with a shift to smaller sized zooplankton and a change in species abundance. Further research is required to assess how much of the change in zooplankton community structure and activity can be attributed to changes in food quality, rather than to changes in temperature and food quantity.
3
Finenko, G. A., N. A. Datsyk, S. M. Ignatyev, and B. E. Anninsky. "Spatial variability and trophic characteristics of jellyfish populations in the Crimea marine area in summer." Marine Biological Journal 4, no. 2 (June 24, 2019): 71–86. http://dx.doi.org/10.21072/mbj.2019.04.2.08.
Full textAbstract:
The existence of two alternative points of view on the long-term dynamics of gelatinous macroplankton populations in the World Ocean determines the need for long-term monitoring as a basis for assessing their condition. The accumulation of long-term series of data on the development of gelatinous predators in the Black Sea makes it possible to assess their role in the functioning of the pelagic ecosystem in connection with climatic variability. The abundance, biomass, the size structure of the gelatinous predators (jellyfish Aurelia aurita; ctenophores Mnemiopsis leidyi and Pleurobrachia pileus) and the feeding intensity of the two species (A. aurita and M. leidyi) were investigated in the early summer period (June) of 2016 at 45 stations covering the shelf zone off the coast of Crimea from Cape Tarkhankut to Kerch, as well as at 3 stations of the deepwater area with the coordinates 44°23′N–45°5′N and 32°22′E–36°36′E. The material was collected from the bottom (10–100 m) up to the surface at the inshore stations and from the depth with σt = 16.2 to the surface – in deepwater by vertical trawls with modified Bogorov – Russ net with an inlet diameter of 80 cm, a mesh of 300 μm. The nutritional spectrum and its quantitative composition were determined under a microscope in the laboratory immediately after the catch of animals, followed by the calculation of diurnal rations and the rate of ingestion of zooplankton. Spatial differences in abundance of gelatinous species were observed: the maximum biomass of A. aurita, prevailing in all regions, was observed in the Yevpatoriya – Sevastopol region and was due to large accumulations of middle-sized specimens of new generation. Ctenophora P. pileus dominated in the abundance in the halistatic zone. The food spectrum of jellyfish was very diverse and included various stages of Copepoda, Tunicata, Cladocera, and also the meroplankton – the Bivalvia and Gastropoda veligers. The halistatic zone with great depths was characterized by the widest species composition of planktonic Copepoda in A. aurita food. The average daily rations of jellyfish varied from one region to another, being the lowest in the Karkinitsky Bay [(0.113 ± 0.10) mg C−1·day−1, or (1.6 ± 2.18) % of C body] with most of the food being algae C. granii. The most intensive feeding was in the halistatic zone [(56.2 ± 23.7) % of C body] with a predominance of Calanus euxinus and Pseudocalanus elongatus in the diet. In no region A. aurita can compensate the respiration requirements by the consumption of mesozooplankton. The highest impact on zooplankton was provided by jellyfish population in the Karkinitsky Bay and in the Yevpatoriya – Sevastopol region, although along all the shelf its impact was very low and did not lead to a dramatic reduction in the zooplankton community abundance.
4
Pinel-Alloul, B. "Zooplankton Community Structure in Hardwater Hypertrophic Lakes of Alberta." Water Science and Technology 27, no. 7-8 (April 1, 1993): 353–61. http://dx.doi.org/10.2166/wst.1993.0570.
Full textAbstract:
Excessive concentrations of phosphorus are a common feature of hardwater eutrophic lakes in western Canada. Preliminary experimental lime treatment showed that this approach had a great potential to reduce phosphorus content and algal biomass. Therefore, two pairs of experimental and reference lakes were selected for a whole lake lime treatment and monitored for a full year prior to manipulation. This study presents the composition and size structure of the Zooplankton community of the lakes before treatment in order to assess the natural summer and inter-lake variations. Before lime treatment, seasonal means of total Zooplankton abundance and biomass ranged from 17 ± 8 to 127 ± 84 ind. L−1 and from 4 ± 2 to 138 ± 236 mg m−3, respectively. The two experimental lakes (Halftnoon and Lofty) were the richest in Zooplankton while the references lakes (Crooked and Jenkins) were the poorest. A total of 30 Zooplankton species (17 rotifers, 2 calanoids, 4 cyclopoids and 7 cladocerans) were recorded as well as 3 chaoborid species. The composition and size structure of Zooplankton varied between lakes and dates. Rotifers accounted for the majority of Zooplankton abundances (59-91%) while Cladocera (78-99%) or Copepoda (74%) in Crooked lake formed most of the Zooplankton biomass. Summer variations of the Zooplankton groups were described along with changes in size spectra. The temporal variation and the inter-lake differences in Zooplankton structure were discussed in relation to trophy, fish and invertebrate predation, and cyanophyte interactions.
5
Turner, Andrew M., and Gary G. Mittelbach. "Effects of Grazer Community Composition and Fish on Algal Dynamics." Canadian Journal of Fisheries and Aquatic Sciences 49, no. 9 (September 1, 1992): 1908–15. http://dx.doi.org/10.1139/f92-211.
Full textAbstract:
We examined the effects of grazer community composition and fish on phytoplankton abundance by manipulating zooplankton community structure and the intensity of planktivory in a factorial experiment. Enclosures (1700-L bags) were treated with fish (present/absent) and two grazer communities (one a large-bodied community dominated by Daphnia and the other a small-bodied community dominated by Ceriodaphnia) in a 2 × 2 factorial design. We sampled zooplankton and algae every 4–8 d during the 5-wk experiment. Algal biovolume, chlorophyll a, total particulates, and light extinction were all significantly higher in the presence of fish. Further, the effect of fish on algal standing crop did not depend on which grazer assemblage was initially present. Fish enhanced algal standing crop to the same degree in both Daphnia and Ceriodaphnia treatments. We discuss these results in light of patterns reported in the literature, and the nature of size-structured interactions among fish, zooplankton, and algae.
6
Leavitt, P. R., and S. R. Carpenter. "Regulation of Pigment Sedimentation by Photo-Oxidation and Herbivore Grazing." Canadian Journal of Fisheries and Aquatic Sciences 47, no. 6 (June 1, 1990): 1166–76. http://dx.doi.org/10.1139/f90-136.
Full textAbstract:
Reversed-phase high pressure liquid chromatography was used to show that algal carotenoid sedimentation is regulated by photo-oxidation and herbivore grazing in three unproductive, north-temperate lakes. Comparison of algal carotenoid and biovolume standing stocks revealed that carotenoid concentrations in epilimnetic waters were influenced by nonplanktonic inputs of pigments as well as phytoplankton community composition. Sediment traps did not record weekly events in the water column. Pigments that were incorporated in zooplankton feces and sank rapidly (e.g. alioxanthm and pheophorbide a) were overrepresented in trap material relative to epilimnetic pigment standing stocks. Differential decay of pigments in traps could not account for this observed bias. Chlorophyll mass–balance budgets corroborated the important influence of grazing by large-bodied zooplankton on pigment sedimentation. Interannual differences in pigment sedimentation were caused by changes in zooplankton community structure and the vertical zonation of phytoplankton communities. In the absence of fecal transportation, photo-oxidation destroyed carotenoids prior to their sedimentation from the photic zone. Therefore, sedimentary carotenoid composition is regulated by loss processes as well as changes in algal community composition.
7
Pinto-Coelho, R. M., A. Giani, C. A. Morais-Jr., E. R. Carvalho-Jr., and J. F. Bezerra-Neto. "The nutritional status of zooplankton in a tropical reservoir: effects of food quality and community structure." Brazilian Journal of Biology 65, no. 2 (May 2005): 313–24. http://dx.doi.org/10.1590/s1519-69842005000200016.
Full textAbstract:
The temporal variability of energetic reserves of zooplankton in the eutrophic Pampulha reservoir was investigated during two successive annual cycles. The effects of dominance of large filter-feeding cladocerans (Daphnia) and the occurrence of massive blooms of the cyanobacteria Microcystis on the energetic reserves of zooplankton were tested. This study showed that phytoplankton composition has a greater effect on energetic reserves of zooplankton. Some associations between lipid levels and the specific composition of zooplankton were also found. This study also demonstrated that the elementary composition of phosphorus in zooplankton can be used as an estimator of the nutritional status of zooplankton.
8
Angeler, David G., Silvia Martín, Marta Rodríguez, and José M. Moreno. "Application-rate-dependent impacts of a fire retardant on zooplankton community structure of temporary ponds." Marine and Freshwater Research 56, no. 2 (2005): 197. http://dx.doi.org/10.1071/mf04271.
Full textAbstract:
In the present study, we employed dry sediments in a temporary-pond microcosm experiment to evaluate the response of the zooplankton community after exposure to different application rates of the commercially available fire retardant, Fire-Trol 934. Application rates were selected to reflect ranges used during fire control/prevention operations in grasslands and shrublands in Mediterranean areas. Results show loss of water quality in terms of increased nutrient (total phosphorus and total nitrogen) concentrations, electrical conductivity and water colour. The magnitude of water-quality impact depended on FRC application rate and was most severe in the highest application rate treatment. The zooplankton community was significantly affected by the FRC treatments. In the control, a diverse assemblage of cladocerans, rotifers and ostracods developed, whereas the zooplankton community in all FRC treatments was depauperate, consisting only of a few species of rotifers. The lack of cladocerans, which are effective grazers of phytoplankton, could negatively affect ecosystem functioning and foster eutrophication effects through excessive algal growth, at least during the first weeks after temporary ponds fill with winter rains.
9
Wang, Weicheng, Guangtao Zhang, Xiaoxia Sun, Fang Zhang, and Xing Zhang. "Temporal variability in zooplankton community in the western Yellow Sea and its possible links to green tides." PeerJ 7 (April 8, 2019): e6641. http://dx.doi.org/10.7717/peerj.6641.
Full textAbstract:
Large-scale macro-algal blooms ofUlva prolifera(also called green tides) have appeared each summer since 2008 in the western Yellow Sea. In this study, we investigated the temporal variability in zooplankton community in the western Yellow Sea and its possible links to green tides using data from a long-term plankton survey off the coast of Qingdao, China. Environmental conditions observed in the study area during the green tide period (GTP: June–August, 2008–2013) were compared to the non-green tide period (NGTP: June–August, 2005–2007), to support the contention that variations observed in zooplankton community may be attributed to the green tides, as opposed to natural climatic or environmental variations. Zooplankton assemblage structure observed during the GTP was then compared to the NGTP. Significant variations were detected both in zooplankton abundance and assemblage structure between the two defined periods. The abundance of zooplankton, mainly copepods, was significantly decreased during the GTP. Meanwhile, the relative abundance of copepods decreased by approximately 10% and that of gelatinous zooplankton, including appendicularians, chaetognaths, and medusae, almost doubled (ca. increased by 6.4%). The dominant species of meroplankton completely changed, specifically, polychaeta, and echinoderm larvae were more dominant than decapod and bivalve larvae. With regard to zooplankton size structure, the NGTP showed a higher size diversity with more small-sized organisms, while the GTP showed a lower size diversity in the community. According to general linear models, the interannual variation in summer zooplankton abundance was significantly correlated with green tides. These results indicate that the temporal changes in zooplankton community may have a close link to the green tides.
10
Ehlinger, Timothy J. "Foraging Mode Switches in the Golden Shiner (Notemigonus crysoleucas)." Canadian Journal of Fisheries and Aquatic Sciences 46, no. 7 (July 1, 1989): 1250–54. http://dx.doi.org/10.1139/f89-161.
Full textAbstract:
Golden shiners (Notemigonus crysoleucas) use two distinct foraging modes when feeding on zooplankton. Shiners particulate-feed on large cladocerans, visually locating and attacking individual prey items. Shiners also pump filter-feed on high densities of small zooplankton, using no apparent visual cues to detect prey. Particulate-feeding and filter-feeding functional response curves were determined from laboratory experiments. Particulate-feeding rates on Daphnia pulex increased with shiner size, but filter-feeding rates on Bosmina decreased with shiner size. Experiments with both prey types present simultaneously revealed that shiners can switch between foraging modes on a short time scale which increases their total foraging return by filter-feeding on Bosmina in between Daphnia encounters. This behavioral flexibility has consequences for both fish and zooplankton community structure in winterkill lakes. The ability to switch feeding modes on a short time scale allows shiners to exist in lakes that are dominated by small zooplankton yet still provides a mechanism to effectively remove large cladocerans when they are encountered.
11
Shen, Anglu, Wenwen Chen, Yongjiu Xu, and Kin-Chung Ho. "Zooplankton Population and Community Structure Changes in Response to a Harmful Algal Bloom Caused by Prorocentrum donghaiense in the East China Sea." Journal of Marine Science and Engineering 10, no. 2 (February 19, 2022): 291. http://dx.doi.org/10.3390/jmse10020291.
Full textAbstract:
Blooms of the dinoflagellate Prorocentrum donghaiense have had adverse impacts on marine ecosystems. However, ecological details, particularly the impacts and processes of the P. donghaiense bloom on the zooplankton community structure are poorly known. We investigated the changes of zooplankton communities in situ within the whole process of a P. donghaiense bloom in the coastal waters in southern Zhejiang Province, China, in May 2016. Results showed that ecological changes during the blooms of P. donghaiense could be divided into three major phases, namely the growth, maintenance, and dissipation phases with regard to the cell abundance of P. donghaiense by bottle sampling of plankton. A total of 42 species of zooplankton were identified. The average abundance and species number of zooplankton in the growth phase were significantly higher than those in the maintenance and dissipation phases. It is shown that the top-two highest proportions of zooplankton in the growth phase were small jellyfishes and copepods, while small jellyfishes and chaetognaths, and copepoda larvae and chaetognaths were the top-two highest in the maintenance and dissipation phases respectively. However, the values of biodiversity index have no statistically significant differences between the three phases. The present results suggested that P. donghaiense bloom produced significant negative impacts on the abundance and species composition of zooplankton with particular reference to copepods.
12
Havens, Karl E. "Complex Analyses of Plankton Structure and Function." Scientific World JOURNAL 1 (2001): 119–32. http://dx.doi.org/10.1100/tsw.2001.19.
Full textAbstract:
This paper critically evaluates some complex methods that have been used to characterize the structure and function of freshwater plankton communities. The focus is on methods related to plankton size structure and carbon transfer. The specific methods reviewed are 1) size spectrum analysis, 2) size-fractionated phytoplankton productivity, 3) size-fractionated zooplankton grazing, 4) plankton ecological transfer efficiency, and 5) grazer effects on phytoplankton community structure. Taken together, these methods can provide information on community ecological properties that are directly related to practical issues including water quality and fisheries productivity. However, caution is warranted since application without a complete understanding of assumptions and context of the manipulations could lead to erroneous conclusions. As an example, experimental studies involving the addition or removal of zooplankton, especially when coupled with nutrient addition treatments, could provide information on the degree of consumer vs. resource control of phytoplankton. Resource managers subsequently could use this information in developing effective measures for controlling nuisance algal biomass. However, the experiments must be done critically and with sufficient safeguards and other measurements to ensure that treatments (e.g., zooplankton exclosure by screening of water) actually are successful and do not introduce other changes in the community (e.g., removal of large algae). In all of the methods described here, the investigator must take care when generalizing results and, in particular, carry out a sufficient number of replications to encompass both the major seasonal and spatial variation that occurs in the ecosystem.
13
Hail, Donald J., and Timothy J. Ehlinger. "Perturbation Planktivory, and Pelagic Community Structure: The Consequence of Winterkill in a Small Lake." Canadian Journal of Fisheries and Aquatic Sciences 46, no. 12 (December 1, 1989): 2203–9. http://dx.doi.org/10.1139/f89-271.
Full textAbstract:
The top predator (largemouth bass, Micropterus salmoides) in eutrophic Wintergreen Lake, Michigan, was eliminated by successive winterkills in 1978 and 1979. Within 2 yr, the golden shiner (Notemigonus crysoleucas), a facultative planktivore, dominated the fish community. The zooplankton, previously consisting of large Daphnia pulex and D. galeata mendotae, concomitantly shifted to a community consisting of smaller species: Bosmina and small copepods. In situ fish enclosure experiments in 1981 and 1982 revealed that the large Daphnia species would grow in Wintergreen Lake in the absence of the golden shiner. Golden shiners exhibit both a particulate and filtering mode of planktivory on large and small zooplankton, respectively. This flexible feeding behavior suggests that golden shiners are able to prevent the reestablishment of Daphnia, while Bosmina and the other small zooplankton support a high and apparently stable golden shiner density.
14
Arias, María Julieta, Pablo Andrés Vaschetto, Mercedes Marchese, Luciana Regaldo, and Ana María Gagneten. "Benthic Macroinvertebrates and Zooplankton Communities as Ecological Indicators in Urban Wetlands of Argentina." Sustainability 14, no. 7 (March 29, 2022): 4045. http://dx.doi.org/10.3390/su14074045.
Full textAbstract:
Urban aquatic ecosystems are important sources of fresh water for multiple uses, but often receive a point or diffuse anthropic contamination. Benthic and zooplankton invertebrates are sensitive to water quality, being good indicators of ecosystem health. In this study, the composition and structure of benthic and zooplankton communities and environmental variables were analyzed seasonally in six urban wetlands of Santa Fe City (Argentina). We present the effect of water quality on both communities as bioindicators of ecological conditions, using different community attributes, functional feeding groups, and biotic indices. For the benthic community, the Macroinvertebrate Index for Pampean Rivers (IMRP) and the Benthic Community Index (BCI) were selected. For the zooplankton community, abundance of rotifers/abundance of total zooplankters, microcrustaceans/total zooplankters, cladocerans/total zooplankters, and macrozooplankton/microzooplankton ratios were applied. A functional feeding groups (FFGs) classification, adapted from the literature, is proposed for zooplankters. The urban wetlands showed a gradient from the most to the least disturbed sites. Some benthic and zooplankton species were identified as excellent bioindicators of pollution, and the FFGs and biotic indices revealed the ecological condition of each urban wetland. The present study contributes to the enhancement of management practices in urban landscapes aiming to maintain ecosystem services in sustainable cities.
15
Afonina, E. Yu, and N. A. Tashlykova. "Species diversity of phyto- and zooplankton in the water bodies of Kharanorskaya State District Power Plant, Transbaikalia (according to 2019 data)." IOP Conference Series: Earth and Environmental Science 908, no. 1 (November 1, 2021): 012037. http://dx.doi.org/10.1088/1755-1315/908/1/012037.
Full textAbstract:
Abstract We described the taxonomic structure of planktonic associations in the water bodies of Kharanor State District Power Plant (cooling pond, water supply, drainage, and water intake channels of Kharanor reservoir located in the arid zone of the south-eastern Transbaikalia in a highly continental climate). Hydrobiological researches were conducted in April, July, and October 2019. We identified 141 algal taxa ranked below the genus, representing the divisions of Cyanobacteria (15 taxa), Bacillariophyta (41), Chrysophyta (10), Cryptophyta (3), Dinophyta (4), Charophyta (8), Chlorophyta (56), and Euglenophyta (4), and 52 zooplankton taxa, including 28 species and subspecies of Rotifera, 15 species of Cladocera, and 9 species of Copepoda. In the cooling reservoir, the plankton community included 135 phytoplankton taxa and 38 zooplankton species; 58 algal taxa and 27 invertebrate species were sampled in the water supply channel, 50 taxa and 26 species were sampled in the drainage channel, and 94 taxa and 24 species were collected from water intake channel respectively. Six diatom species (Stephanodiscus hantzschii, Nitzschia sigmoidea, Fragilaria radians, Asterionella formosa, Ulnaria ulna) and four zooplankton species (rotifers Asplanchna priodonta and crustaceans Daphnia galeata, Bosmina longirostris, Thermocyclops crassus) occurred in all water bodies during the entire study period.
16
Zhang, Xia, Ping Xie, and Xiaoping Huang. "A Review of Nontraditional Biomanipulation." Scientific World JOURNAL 8 (2008): 1184–96. http://dx.doi.org/10.1100/tsw.2008.144.
Full textAbstract:
The aim of this review is to identify problems, find general patterns, and extract recommendations for successful management using nontraditional biomanipulation to improve water quality. There are many obstacles that prevent traditional biomanipulation from achieving expectations: expending largely to remove planktivorous fish, reduction of external and internal phosphorus, and macrophyte re-establishment. Grazing pressure from large zooplankton is decoupled in hypereutrophic waters where cyanobacterial blooms flourish. The original idea of biomanipulation (increased zooplankton grazing rate as a tool for controlling nuisance algae) is not the only means of controlling nuisance algae via biotic manipulations. Stocking phytoplanktivorous fish may be considered to be a nontraditional method; however, it can be an effective management tool to control nuisance algal blooms in tropical lakes that are highly productive and unmanageable to reduce nutrient concentrations to low levels.Although small enclosures increase spatial overlap between predators and prey, leading to overestimates of the impact of predation, microcosm and whole-lake experiments have revealed similar community responses to major factors that regulate lake communities, such as nutrients and planktivorous fish. Both enclosure experiments and large-scale observations revealed that the initial phytoplankton community composition greatly impacted the success of biomanipulation. Long-term observations in Lake Donghu and Lake Qiandaohu have documented that silver carp (Hypophthalmichthys molitrix) and bighead carp (H. nobilis) (two filter-feeding planktivorous species commonly used in management) can suppress Microcystis blooms efficiently. The introduction of silver and bighead carp could be an effective management technique in eutrophic systems that lack macrozooplankton. We confirmed that nontraditional biomanipulation is only appropriate if the primary aim is to reduce nuisance blooms of large algal species, which cannot be controlled effectively by large herbivorous zooplankton. Alternatively, this type of biomanipulation did not work efficiently in less eutrophic systems where nanophytoplankton dominated.
17
Rong, Yuqin, Yali Tang, Lijuan Ren, William D. Taylor, Vladimir Razlutskij, Luigi Naselli-Flores, Zhengwen Liu, and Xiufeng Zhang. "Effects of the Filter-Feeding Benthic Bivalve Corbicula fluminea on Plankton Community and Water Quality in Aquatic Ecosystems: A Mesocosm Study." Water 13, no. 13 (June 30, 2021): 1827. http://dx.doi.org/10.3390/w13131827.
Full textAbstract:
The influence of filter-feeding bivalves on plankton communities, nutrients, and water quality in a given aquatic ecosystem is so profound that they can be considered ecosystem engineers. In a 70-day mesocosm experiment, we tested the hypothesis that Corbicula fluminea would change plankton community structure by reducing small zooplankton and large phytoplankton and improve water quality by reducing nutrients. We monitored levels of nitrogen and phosphorus, organic suspended solids (OSS), and light at the sediment surface. Within the plankton, phytoplankton biomass (as Chl a, >0.45 μm), the biomass of microphytoplankton (>20 μm), nanophytoplankton (2–20 μm), picophytoplankton (0.2–2 μm), and zooplankton were determined. Compared with the controls, C. fluminea reduced the abundance of rotifers and the biomass of phytoplankton, and picophytoplankton, thereby modifying the plankton community structure. We did not observe reductions in TN and TP concentration, but OSS concentrations were reduced, and light intensity at the sediment surface was increased as a result of the improved water transparency. Our research shows that colonization by C. fluminea may modify plankton community structure and improve water quality of eutrophic shallow lakes, shedding further light on the ecological roles of filter-feeding bivalves in aquatic ecosystems.
18
Threlkeld, Stephen T. "Differential temperature sensitivity of two cladoceran species to resource variation during a blue-green algal bloom." Canadian Journal of Zoology 64, no. 8 (August 1, 1986): 1739–44. http://dx.doi.org/10.1139/z86-262.
Full textAbstract:
The sensitivity of life-table parameters of two cladoceran zooplankton to slight, natural variations in temperature was determined during the onset of a midsummer blue-green algal bloom in a large turbid reservoir (Lake Texoma, Oklahoma, Texas). Prior to the onset of blue-green algae, cohorts of Ceriodaphnia lacustris incubated at ambient epilimnion temperatures (27–30 °C) had higher individual somatic and population growth rates, an earlier age at first reproduction, and shorter life-spans than cohorts incubated at a constant 25 °C. As blue-green algae became abundant, Ceriodaphnia growth rates were reduced more dramatically at ambient temperatures than at 25 °C, suggesting that a temperature–resource interaction was important to determination of somatic growth rate, age of first reproduction, and population growth rate. Ceriodaphnia populations declined in Lake Texoma as blue-green algae became abundant. Diaphanosoma leuchtenbergianum, which was abundant throughout the period of blue-green algal dominance, did not show the temperature–resource interaction found for Ceriodaphnia. Temperature–resource interactions have been hypothesized to determine seasonal change in zooplankton community structure; this study provides experimental evidence of demographic consequences in natural populations of one kind of common temperature–resource interaction.
19
Balazy, Kaja, Emilia Trudnowska, and Katarzyna Błachowiak-Samołyk. "Dynamics of Calanus Copepodite Structure during Little Auks’ Breeding Seasons in Two Different Svalbard Locations." Water 11, no. 7 (July 9, 2019): 1405. http://dx.doi.org/10.3390/w11071405.
Full textAbstract:
Populations dynamics of key zooplankton species in the European Arctic, Calanus finmarchicus and Calanus glacialis (hereafter defined as Calanus) may be sensitive to climate changes, which in turn is of great importance for higher trophic levels. The aim of this study was to investigate the complete copepodite structure and dynamics of Calanus populations in terms of body size, phenology and their relative role in the zooplankton community over time in different hydrographic conditions (two fjords on the West Spitsbergen Shelf, cold Hornsund vs. warm Kongsfjorden), from the perspective of their planktivorous predator, the little auk. High-resolution zooplankton measurements (taken by nets and a laser optical plankton counter) were adapted to the timing of bird’s breeding in the 2015 and 2016 summer seasons, and to their maximal diving depth (≤50 m). In Hornsund, the share of the Calanus in zooplankton community was greater and the copepodite structure was progressively older over time, matching the little auks timing. The importance of Calanus was much lower in Kongsfjorden, as represented mainly by younger copepodites, presumably due to the Atlantic water advections, thus making this area a less favourable feeding ground. Our results highlight the need for further studies on the match/mismatch between Calanus and little auks, because the observed trend of altered age structure towards a domination of young copepodites and the body size reduction of Calanus associated with higher seawater temperatures may result in insufficient food availability for these seabirds in the future.
20
Gulati, R. D. "Structure and feeding activities of zooplankton community in Lake Zwemlust, in the two years after biomanipulation." Hydrobiological Bulletin 23, no. 1 (March 1989): 35–48. http://dx.doi.org/10.1007/bf02286425.
Full text
21
Winkler, Gesche, Pascal Sirois, Ladd E. Johnson, and Julian J. Dodson. "Invasion of an estuarine transition zone by Dreissena polymorpha veligers had no detectable effect on zooplankton community structure." Canadian Journal of Fisheries and Aquatic Sciences 62, no. 3 (March 1, 2005): 578–92. http://dx.doi.org/10.1139/f04-230.
Full textAbstract:
Large numbers of the filter-feeding larval stage of zebra mussels (Dreissena polymorpha) (veligers) have been advected into the estuarine transition zone (ETZ) of the St. Lawrence River. In 1994, they became the dominant member of the tidal freshwater zooplankton assemblage of the ETZ (and subsequently the true estuarine assemblage) during summer months. These changes in community structure have not, however, been reflected in changes in the abundance of preinvasion taxa. Abundance of potential planktonic competitors such as rotifers and the cladoceran Bosmina longirostris fluctuated between years but did not decline following the invasion. Only densities of the copepod Eurytemora affinis declined in 2000 and 2001, but this could not be definitively associated with the invasion. Synchronous variation among different zooplankton groups suggests that environmental forcing related to or correlated with temperature anomalies is the major cause of interannual variation in the abundance of zooplankton taxa. The negative correlation between veliger abundance and salinity indicates that the ETZ acts as a sink for the larval stages of the zebra mussel. Their precise fate remains uncertain, but our study suggests that this invasion has had little or no impact on this pelagic community in spite of the numerical dominance of veligers.
22
Hejzlar, J., P. Dolejš, J. Komárková, J. Sed′a, K. Šimek, and V. Vyhnálek. "Effect of biomanipulation on the structuring of the planktonic food web and water treatability by coagulation." Water Science and Technology 37, no. 2 (January 1, 1998): 105–12. http://dx.doi.org/10.2166/wst.1998.0116.
Full textAbstract:
The impact of planktivorous fish on the plankton community structure and character of aquatic organic matter was studied by a meso-scale enclosure experiment in a stratified reservoir. Aims of the study were (i) to examine the response of the communities with and without herbivorous zooplankton to an increased input of phosphorus and (ii) to determine the composition and coagulation properties of the organic matter produced by these communities. The concentration and composition of organic matter were affected both in the enclosure with planktivorous fish (F), where high algal biomass developed, and in the enclosure without fish (Z), where algae were maintained at a low concentration by zooplankton grazing. Although differences between the enclosures in concentrations of total dissolved organic matter and its hydrophobic, hydrophilic and neutral/basic fractions were relatively small, coagulation properties of the organics differed substantially. Particulate and dissolved organic matter produced in enclosure F had a positive effect on the efficiency of alum coagulation in contrast to the less readily separable organics produced in enclosure Z. The results indicate that pelagic food web manipulations to maintainin low phytoplankton biomass by zooplankton grazing may not always have positive effects on the treatability of water by coagulation.
23
Titocci, Jessica, Melanie Bon, and Patrick Fink. "Morpho-Functional Traits Reveal Differences in Size Fractionated Phytoplankton Communities but Do Not Significantly Affect Zooplankton Grazing." Microorganisms 10, no. 1 (January 14, 2022): 182. http://dx.doi.org/10.3390/microorganisms10010182.
Full textAbstract:
The recent emergence of approaches based on functional traits allows a more comprehensive evaluation of the role of functions and interactions within communities. As phytoplankton size and shape are the major determinants of its edibility to herbivores, alteration or loss of some morpho-functional phytoplankton traits should affect zooplankton grazing, fitness and population dynamics. Here, we investigated the response of altered phytoplankton morpho-functional trait distribution to grazing by zooplankton with contrasting food size preferences and feeding behaviors. To test this, we performed feeding trials in laboratory microcosms with size-fractionated freshwater phytoplankton (3 size classes, >30 µm; 5–30 µm and <5 µm) and two different consumer types: the cladoceran Daphnia longispina, (generalist unselective filter feeder) and the calanoid copepod Eudiaptomus sp. (selective feeder). We observed no significant changes in traits and composition between the controls and grazed phytoplankton communities. However, community composition and structure varied widely between the small and large size fractions, demonstrating the key role of size in structuring natural phytoplankton communities. Our findings also highlight the necessity to combine taxonomy and trait-based morpho-functional approaches when studying ecological dynamics in phytoplankton-zooplankton interactions.
24
Ohman, Mark D. "A sea of tentacles: optically discernible traits resolved from planktonic organisms in situ." ICES Journal of Marine Science 76, no. 7 (August 3, 2019): 1959–72. http://dx.doi.org/10.1093/icesjms/fsz184.
Full textAbstract:
Abstract Trait-based simplifications of plankton community structure require accurate assessment of trait values as expressed in situ. Yet planktonic organisms live suspended in a fluid medium and often bear elongate appendages, delicate feeding structures, and mucous houses that are badly damaged upon capture or removal from the fluid environment. Fixatives further distort organisms. In situ imaging of zooplankton from a fully autonomous Zooglider reveals a suite of trait characteristics that often differ markedly from those inferred from conventionally sampled plankton. In situ images show fragile feeding appendages in natural hunting postures, including reticulate networks of rhizopods, feeding tentacles of cnidarians, and tentilla of ctenophores; defensive spines and setae of copepods; intact mucous houses of appendicularians; and other structures that are not discernible in conventionally collected zooplankton. Postures characteristic of dormant copepods can be identified and the presence of egg sacs detected. Intact, elongate diatom chains that are much longer than measured in sampled specimens are resolvable in situ. The ability to image marine snow, as well as small-scale fluid deformations, reveals micro-habitat structure that may alter organismal behaviour. Trait-based representations of planktonic organisms in biogeochemical cycles need to consider naturally occurring traits expressed by freely suspended planktonic organisms in situ.
25
Riegman, R. "Nutrient-related selection mechanisms in marine phytoplankton communities and the impact of eutrophication on the planktonic food web." Water Science and Technology 32, no. 4 (August 1, 1995): 63–75. http://dx.doi.org/10.2166/wst.1995.0167.
Full textAbstract:
A general increase in nutrient discharges during the last few decades has caused various changes in the algal community structure along the European continental coast. Coincidentally and maybe consequently, the foodweb structure and functioning has altered in local areas causing various phenomena like oxygen depletion, mortality of groups of organisms, foam on beaches, and an increase in the productivity of benthic communities and some commercial fish species. The observed increases in algal biomass and shifts in species composition are discussed in relation to the involved key mechanisms: resource competition and selective grazing. Along the Dutch coastal zone of the North Sea eutrophication has caused a doubling of the yearly averaged algal biomass during the past three decades. The sudden appearance of Phaeocystis summer blooms coincided with a shift from P-limitation towards N-limitation in the Dutch coastal area due to a stronger increase in P-discharge relative to the increase in N-discharge. Competition experiments in continuous cultures showed Phaeocystis to become dominant under N-limitation. Additionally, the large Phaeocystis colonies, which can reach a diameter up to one centimetre, escape from microzooplankton grazing. A computer model is presented which demonstrates a shift from bottom-up towards top-down control if the pelagic environment becomes eutrophicated. Implementation of this concept in a size-differential phytoplankton control model generates the prediction that algal blooms are dominated by species that escape from grazing by those zooplankton species which have a high potential numerical response. In marine environments these are microzooplankton species. These organisms mainly feed on cyanobacteria, prochlorophytes and some nano-algal species. One of the consequences for foodweb structure and the carbon fluxes in marine foodwebs is that eutrophication will lead to the dominance of poorly edible algal species. Eutrophication favours the downward transport of carbon and nutrients towards the sediments not only due to higher algal biomasses but also as a consequence of a shift towards larger algal species with higher sedimentation characteristics. An example is given how these new insights can be used for water quality management purposes.
26
Elser, James J., Monica M. Elser, and Stephen R. Carpenter. "Size fractionation of algal chlorophyll, carbon fixation and phosphatase activity: relationships with species-specific size distributions and zooplankton community structure." Journal of Plankton Research 8, no. 2 (1986): 365–83. http://dx.doi.org/10.1093/plankt/8.2.365.
Full text
27
Beisner, B. E., E. McCauley, and F. J. Wrona. "The influence of temperature and food chain length on plankton predatorprey dynamics." Canadian Journal of Fisheries and Aquatic Sciences 54, no. 3 (March 1, 1997): 586–95. http://dx.doi.org/10.1139/f96-312.
Full textAbstract:
With recent predictions for global climate warming, the question arises as to how changes in temperature influence the dynamics of populations in natural communities. We investigated the effect of temperature (18 and 25°C) on the stability of a common freshwater predator-prey system consisting ofDaphnia pulex and phytoplankton in different types of mesocosm communities. The plant-herbivore dynamics were examined in the presence and absence of the predator Mesostoma ehrenbergii to simulate food chains of two or three trophic levels, and in the presence or absence of competing zooplankton. The predator-prey system was destabilized at the higher temperature in all types of communities, and D. pulex extinction always occurred. This result was unaffected by simplification of the community but was enhanced by the addition of the carnivore. Mechanisms are proposed for the observed results including (i) the direct effect of temperature on vital rate parameters describing the D. pulex - algal interaction and (ii) a shift in algal community structure to less edible species following suppression by the herbivore at the higher temperature. Some implications of temperature increases expected under current global warming scenarios in pond systems are discussed.
28
Drira, Zaher, Malika Belhassen, Habib Ayadi, Asma Hamza, Rafik Zarrad, Abderrahmen Bouaïn, and Lotfi Aleya. "Copepod community structure related to environmental factors from a summer cruise in the Gulf of Gabès (Tunisia, eastern Mediterranean Sea)." Journal of the Marine Biological Association of the United Kingdom 90, no. 1 (July 9, 2009): 145–57. http://dx.doi.org/10.1017/s0025315409990403.
Full textAbstract:
We studied the summer spatial distribution of the copepod community in both the neritic and oceanic areas of the Gulf of Gabès (Tunisia, eastern Mediterranean Sea) coupled with environmental factors. Copepods were the most abundant zooplankton throughout the sampling period, contributing 78% of the total zooplankton. A total of 14 copepod families were identified in all stations, with an overwhelming abundance of Acartiidae and Oithonidae (39.05 and 39.09% of total abundance, respectively). Abundance of Acartia clausi and chlorophyll-a concentrations were negatively correlated with salinity, suggesting that this species probably escaped the high coastal salinity (38 psu). Significant correlation determined between A. clausi and tintinnids at 50 m isobaths indicates that these planktonic ciliates probably served as a substantial food link towards higher trophic levels of this area. Conversely, Oithona nana which was well adapted to high chlorophyll-a concentrations and high salinity along the coast, showed significant correlations with Dictyochophyceae, Dinophyceae, Bacillariophyceae and Euglenophyceae, suggesting that this small copepod was capable of feeding on a wide selection of phytoplankton preys.
29
Loria, Mark H., James S. Griffin, George F. Wells, and Kurt R. Rhoads. "Effects of feast-famine nutrient regimes on wastewater algal biofuel communities." PLOS ONE 18, no. 1 (January 4, 2023): e0279943. http://dx.doi.org/10.1371/journal.pone.0279943.
Full textAbstract:
Microalgae accumulate lipids in response to nutrient deprivation, and these lipids are a biodiesel fuel stock. Algal cultivation with secondary wastewater effluent is one proposed platform for biofuel production, which provides nutrients to algae while further polishing wastewater effluent. Algal bioreactors were tested using a feast-famine feeding regiment in simulated secondary wastewater effluent to evaluate the effects on lipid content and algal community structure. Algal polycultures were inoculated into reactors fed with synthetic secondary wastewater effluent at pH 7.5 and 9 and operated under a feast-famine nutrient (N, P, and BOD) supply regime in sequencing batch reactors. Fatty acid methyl ester contents of the reactors were assessed, which showed a decrease in lipid content after the feast-famine cycling (from 12.2% initially to 5.2% after four cycles at pH 9). This decrease in lipid content was not correlated with an increase in carbohydrate storage within biomass, nor an increase in bacterial biomass abundance relative to algal biomass in the reactors. The eukaryotic microbial communities from reactors operated at pH 9 diverged from reactors operated at pH 7.5 during cycling, with the pH 9 reactors becoming dominated by a single Operational Taxonomic Unit aligning to the Scenedesmus genus. These results suggest that high pH and feast-famine nutrient cycling may select for a less diverse algal community with a lower lipid content within a secondary wastewater polishing scheme.
30
Lira, Alex Souza, Flávia Lucena-Frédou, Frédéric Ménard, Thierry Frédou, Júlio Guazzelli Gonzalez, Valdimere Ferreira, José Souto Rosa Filho, Jean-Marie Munaron, and François Le Loc’h. "Trophic structure of a nektobenthic community exploited by a multispecific bottom trawling fishery in Northeastern Brazil." PLOS ONE 16, no. 2 (February 8, 2021): e0246491. http://dx.doi.org/10.1371/journal.pone.0246491.
Full textAbstract:
We used complementary stable isotope (SIA) and stomach content (SCA) analyses to investigate feeding relationships among species of the nektobenthic communities and the potential ecological effects of the bottom trawling of a coastal ecosystem in northeastern Brazil. Carbon (δ13C) and nitrogen (δ15N) compositions were determined for five basal sources and 28 consumers, from zooplankton to shrimp and fish species. Fishes and basal sources showed a broad range of δ15N (fishes: 6.49–14.94‰; sources: 2.58–6.79‰) and δ13C values (fishes: -23.86 to -13.71‰; sources: -24.32 to -13.53‰), while shrimps and crabs exhibited similar nitrogen and carbon ratios. Six trophic consumer groups were determined among zooplankton, crustaceans and fishes by SIA, with trophic pathways associated mostly with benthic sources. SCA results indicated a preference for benthic invertebrates, mainly worms, crabs and shrimps, as prey for the fish fauna, highlighting their importance in the food web. In overall, differences between SCA and the SIA approaches were observed, except for groups composed mainly for shrimps and some species of high δ15N values, mostly piscivorous and zoobenthivores. Given the absence of regulation for bottom trawling activities in the area, the cumulative effects of trawling on population parameters, species composition, potentially decreasing the abundance of benthic preys (e.g., shrimps, worms and crabs) may lead to changes in the trophic structure potentially affect the food web and the sustainability of the fishery.
31
Dvoretskiy, Vladimir, and Alexander Dvoretskiy. "Features of winter zooplankton assemblage in the Central Trough of the Barents Sea." Arctic Environmental Research 18, no. 1 (March 30, 2018): 28–36. http://dx.doi.org/10.17238/issn2541-8416.2018.18.1.28.
Full textAbstract:
The Barents Sea is a highly productive shelf region. Zooplankton assemblages are a key component of the carbon cycle in Arctic marine ecosystems; they transfer energy from lower trophic levels to higher levels, including larval and young commercial fish. The winter state of the zooplankton community in the Central Through and their slopes (Barents Sea) was investigated in late November 2010. Vertical structure of water layer was characterised by pycnocline located below 80 m. The upper strata were occupied by transformed Atlantic Water, while winter Barents Sea Water with negative temperatures was in the bottom strata. Total zooplankton abundance varied from 162 to 1214 individuals/m3. Biomass ranged from 88 to 799 mg wet mass/m3. Copepods dominated in terms of total zooplankton abundance (average 99%) and biomass (92%). Maximum densities of Calanusfinmarchicus and Calanusglacialis were registered in the frontal zone separating warm and cold water masses. Abundances of Metridialonga and O.similis were highest in cold waters. Three groups of stations differing in terms of the common copepod composition were delineated with cluster analysis. The age structure of Calanusfinmarchicus and Metridialonga was characterised by a prevalence of copepodites IV–V. Total zooplankton abundance and biomass were correlated to water temperature and salinity, suggesting that hydrological conditions were the key driver of spatial variations of the zooplankton communities. High biomass of large copepods suggests potential significance of the investigated region for feeding of young and adult fish.
32
Irvine, Kenneth. "Differential feeding behaviour of the dominant cladocera as an explanation of zooplankton community structure in the Loosdrecht Lakes." Hydrobiological Bulletin 20, no. 1-2 (November 1986): 121–34. http://dx.doi.org/10.1007/bf02291157.
Full text
33
HART, R. C. "Zooplankton feeding rates in relation to suspended sediment content: potential influences on community structure in a turbid reservoir." Freshwater Biology 19, no. 1 (February 1988): 123–39. http://dx.doi.org/10.1111/j.1365-2427.1988.tb00334.x.
Full text
34
Almeida, LR, IS Costa, and EM Eskinazi-Sant'Anna. "Composition and abundance of zooplankton community of an impacted estuarine lagoon in Northeast Brazil." Brazilian Journal of Biology 72, no. 1 (February 2012): 12–24. http://dx.doi.org/10.1590/s1519-69842012000100002.
Full textAbstract:
Guaraíras Lagoon is a shallow coastal lagoon subject to intense human impacts, including shrimp aquaculture, urban expansion and agricultural activities, and is therefore vulnerable to eutrophication. With the aim of detecting the effects of human-mediated disturbance and environmental change in the lagoon, a spatial-temporal study was conducted in order to assess the actual ecological status of the lagoon and the species composition and density of the mesozooplankton, highlighting copepod assemblages. Algal biomass (chlorophyll-a) and total phosphorus concentration indicated that the lagoon is a meso-eutrophic coastal system in the inner part, and is oligotrophic in the areas influenced by the marine waters. High salinities were recorded in the lagoon, characterizing the lagoon as a coastal-marine ecosystem, rather than true estuarine. Mesozooplankton abundance fluctuated widely and showed marked spatial heterogeneity. The copepod assemblage was characterized by a coastal/estuarine group dominated by Oithona spp., Acartia lilljeborgi and Parvocalanus crassirostris in the inner areas of the lagoon, and a marine group characterized by the copepods Paracalanus quasimodo, Calanopia americana, Corycaeus (C.) speciosus and Monstrilloida in the area of marine influence. Thus, the spatial variability in the distribution of mesozooplankton species can be ascribed to the presence of a horizontal gradient of salinity and trophic conditions. Overall, the results showed that spatial variation in the water physicochemical characteristics of Guarairas Lagoon have significant effects on the structure and repartition of the mesozooplankton assemblages, which may potentially affect the functioning and biodiversity of this coastal ecosystem.
35
Gu, Binhe, Donald M. Schell, and Vera Alexander. "Stable Carbon and Nitrogen Isotopic Analysis of the Plankton Food Web in a Subarctic Lake." Canadian Journal of Fisheries and Aquatic Sciences 51, no. 6 (June 1, 1994): 1338–44. http://dx.doi.org/10.1139/f94-133.
Full textAbstract:
Carbon and nitrogen stable isotopes (δ13C and δ15N) were used to track energy flow and nutrient cycling pathways in the plankton food web of a subarctic Alaskan lake. Results indicated that planktonic primary production was the major energy source fueling the zooplankton community. In spring, δ15N of Daphnia was strongly influenced by atmospheric nitrogen derived from a N2-fixing blue-green algal bloom. In winter, δ13C evidence suggested that phytoplankton comprised a small fraction (~15%) of particulate organic matter (POM) in the water column, largely due to low primary productivity. The disparity between δ13C of POM and Daphnia in winter may result from preferential assimilation of isotopically light algal carbon from POM. Nitrogen isotope values showed that Heterocope, a presumed carnivore, probably relied heavily on POM as a nutrient source. In common with some arctic lakes, the δ15N data showed less than three trophic levels in this plankton food web. The energy transfer pathways and trophic levels revealed a simple plankton trophic structure in this subarctic lacustrine system.
36
Pratap, Kunal, Marwan E. Majzoub, Aya C. Taki, Socorro Miranda Hernandez, Marie Magnusson, Christopher R. K. Glasson, Rocky de Nys, Torsten Thomas, Andreas L. Lopata, and Sandip D. Kamath. "The Algal Polysaccharide Ulvan and Carotenoid Astaxanthin Both Positively Modulate Gut Microbiota in Mice." Foods 11, no. 4 (February 16, 2022): 565. http://dx.doi.org/10.3390/foods11040565.
Full textAbstract:
The intestinal microbial community (microbiota) is dynamic and variable amongst individuals and plays an essential part in gut health and homeostasis. Dietary components can modulate the structure of the gut microbiota. In recent years, substantial efforts have been made to find novel dietary components with positive effects on the gut microbial community structure. Natural algal polysaccharides and carotenoids have been reported to possess various functions of biological relevance and their impact on the gut microbiota is currently a topic of interest. This study, therefore, reports the effect of the sulfated polysaccharide ulvan and the carotenoid astaxanthin extracted and purified from the aquacultured marine green macroalgae Ulva ohnoi and freshwater green microalgae Haematococcus pluvialis, respectively, on the temporal development of the murine gut microbiota. Significant changes with the increase in the bacterial classes Bacteroidia, Bacilli, Clostridia, and Verrucomicrobia were observed after feeding the mice with ulvan and astaxanthin. Duration of the treatments had a more substantial effect on the bacterial community structure than the type of treatment. Our findings highlight the potential of ulvan and astaxanthin to mediate aspects of host-microbe symbiosis in the gut, and if incorporated into the diet, these could assist positively in improving disease conditions associated with gut health.
37
Hart, R. C. "The effect of inorganic turbidity on zooplankton feeding rates and its related implications to community structure: an experimental analysis." SIL Proceedings, 1922-2010 23, no. 1 (January 1988): 579. http://dx.doi.org/10.1080/03680770.1987.11897983.
Full text
38
Gavrilko, D. E., G. V. Shurganova, I. A. Kudrin, and B. N. Yakimov. "Identification of Freshwater Zooplankton Functional Groups Based on the Functional Traits of Species." Povolzhskiy Journal of Ecology, no. 3 (November 19, 2020): 290–306. http://dx.doi.org/10.35885/1684-7318-2020-3-290-306.
Full textAbstract:
Information on the functional traits of the most widespread species of freshwater zooplankton (Rotifera, Cladocera, and Copepoda) in European Russia was collected and analyzed. Our database includes 355 species described by 4 traits, namely: maximum body length, trophic group, feeding type, and movement type. Cluster analysis based on Gower's functional distances shows that freshwater zooplankton can be classified into 19 groups with different ecological roles. The characteristics of each identified functional group are presented. We believe it to be fundamentally important to build a unified classification using all available data and applicable characters for all three main taxonomic groups of zooplankton. Comparison with the existing ecological zooplankton classification proposed by Yu. S. Chuikov has demonstrated a number of advantages of our approach. Several ecological groups in Yu. S. Chuikov’s classification are represented by more fractional categories in our classification. Our system of functional groups can be used in studies of the structure of zooplanktocoenoses based on direct cluster analysis and ordination or based on functional distances between samples. To calculate the functional similarity between species, one can use our database of features, which is contained in the Appendix. Analysis based on functional groups gives a better unerstanding of the structure of a community than traditional ordination, which takes into account only the taxonomic affiliation of species. The approach used for functional group identification can be useful in assessing functional diversity and identifying patterns of freshwater zooplanktocoenoses dynamics. The database of functional signs of zooplankton can be used to check the relationship of functional signs with environmental factors.
39
González, H. E., R. Giesecke, C. A. Vargas, M. Pavez, J. Iriarte, P. Santibáñez, L. Castro, R. Escribano, and F. Pagès. "Carbon cycling through the pelagic foodweb in the northern Humboldt Current off Chile (23°S)." ICES Journal of Marine Science 61, no. 4 (January 1, 2004): 572–84. http://dx.doi.org/10.1016/j.icesjms.2004.03.021.
Full textAbstract:
Abstract The structure of the zooplankton foodweb and their dominant carbon fluxes were studied in the upwelling system off northern Chile (Mejillones Bay; 23°S) between October 2000 and December 2002. High primary production (PP) rates (1–8 gC m−2 d−1) were mostly due to the net-phytoplankton size fraction (>23 μm). High PP has been traditionally associated with the wind-driven upwelling fertilizing effect of equatorial subsurface waters, which favour development of a short food chain dominated by a few small clupeiform fish species. The objective of the present work was to study the trophic carbon flow through the first step of this “classical chain” (from phytoplankton to primary consumers such as copepods and euphausiids) and the carbon flow towards the gelatinous web composed of both filter-feeding and carnivorous zooplankton. To accomplish this objective, feeding experiments with copepods, appendicularians, ctenophores, and chaetognaths were conducted using naturally occurring plankton prey assemblages. Throughout the study, the total carbon ingestion rates showed that the dominant appendicularian species and small copepods consumed an average of 7 and 5 μgC ind−1 d−1, respectively. In addition, copepods ingested particles mainly in the size range of nano- and microplankton, whereas appendicularians ingested in the range of pico- and nanoplankton. Small copepods and appendicularians removed a small fraction of total daily PP (range 6–11%). However, when the pico- + nanoplankton fractions were the major contributors to total PP (oligotrophic conditions), grazing by small copepods increased markedly to 86% of total PP. Under these more oligotrophic conditions, the euphausiids grazing increased as well, but only reached values lower than 5% of total PP. During this study, chaetognaths and ctenophores ingested an average of 1 and 14 copepods ind−1 d−1, respectively. In terms of biomass consumed, the potential impact of carnivorous gelatinous zooplankton on the small-size copepod community (preferred prey) was important (2–12% of biomass removed daily). However, their impact produced more significant results on copepod abundance (up to 33%), which suggests that carnivorous gelatinous zooplankton may even modulate (control) the abundance of some species as well as the size structure of the copepod community.
40
Magnan, Pierre. "Interactions between Brook Charr, Salvelinus fontinalis, and Nonsalmonid Species: Ecological Shift, Morphological Shift, and Their Impact on Zooplankton Communities." Canadian Journal of Fisheries and Aquatic Sciences 45, no. 6 (June 1, 1988): 999–1009. http://dx.doi.org/10.1139/f88-123.
Full textAbstract:
A quantitative survey of 26 oligotrophic Quebec lakes indicated that the presence of creek chub (Semotilus atromaculatus) or white sucker (Catostomus commersoni) had an impact on brook charr (Salvelinus fontinalis) populations. Evidence for competitive interactions among these species was provided by the observation that (1) the mean annual yield (kilograms per hectare) of charr was significantly reduced when they lived sympatrically with these species, (2) charr shifted their food habits from benthic organisms to Zooplankton in the presence of creek chub and (or) white sucker, and (3) the length of the gill rakers of charr was significantly higher in lakes containing chubs and suckers. As the length of the gill rakers is reported to be correlated with the extent of plankton feeding, this latter result was interpreted as a morphological change associated with increased exploitation of Zooplankton in sympatry. When occurring with creek chub, the niche shift of brook charr resulted in a significant change in Zooplankton community structure. The proportion of large Zooplankton organisms (>1.1 mm) declined whereas that of the smaller ones (<0.6 mm) increased. Also, the mean length of Holopedium, the larger cladocerans, was significantly reduced in sympatric creek chub–charr lakes compared with lakes where charr lived allopatrically. A similar impact on Zooplankton was not as clear when charr occurred with white sucker. When living with white sucker, brook charr populations appeared to be sufficiently reduced as to have little or no effect on Zooplankton communities.
41
Zettler, Erik R., and John C. H. Carter. "Zooplankton Community and Species Responses to a Natural Turbidity Gradient in Lake Temiskaming, Ontario–Quebec." Canadian Journal of Fisheries and Aquatic Sciences 43, no. 3 (March 1, 1986): 665–73. http://dx.doi.org/10.1139/f86-080.
Full textAbstract:
Lake Temiskaming, a long, narrow lake between Ontario and Quebec, contains a permanent turbidity gradient, although seasonal turbidity values continually change throughout. Polar ordination indicated that the crustacean plankton community structure was closely related to the first (turbidity) axis. Mean body size was also positively related to turbidity, suggesting that reduced transparency in turbid waters might protect large zooplankters from visually seeking fish predators. Mysis relicta and Leptodora kindtii, the two largest species, were most abundant at the lake's turbid (northern) end with declining numbers toward the clear (southern) end. Many smaller copepods and cladocerans showed reduced numbers at the northern stations during the turbidity maximum in early June, possibly because of impaired feeding ability, after which they progressively increased through the season relative to numbers in the south. Daphnia galeata mendotae failed to show this seasonal increase at the turbid end, possibly because of selective cropping by Mysis and Leptodora. Many species displayed somewhat higher midday vertical distributions in turbid than in clear waters.
42
Stephan, Lígia R., Beatrix E. Beisner, Samuel G. M. Oliveira, and Maria Stela M. Castilho-Noll. "Influence of Eichhornia crassipes (Mart) Solms on a Tropical Microcrustacean Community Based on Taxonomic and Functional Trait Diversity." Water 11, no. 11 (November 19, 2019): 2423. http://dx.doi.org/10.3390/w11112423.
Full textAbstract:
Macrophytes are important structural attributes of freshwater ponds and wetlands, affecting zooplankton community composition. One of the best-known macrophytes in the world is Eichhornia crassipes, which, due to its high reproductive rate, can quickly occupy large areas of aquatic environments. However, there have been few assessments of the direct effect of this macrophyte, in the absence of predators, for tropical zooplankton communities. The aim of this study was to evaluate the influence of E. crassipes on microcrustacean community structure using species and functional diversity, the latter providing an important tool to evaluate the response to changes in resource availability along an environment gradient. We also evaluated which functional traits were favored when the structural niche offered by submerged parts of the macrophytes was present. We conducted a 30 day mesocosm experiment (117 m3) with and without the presence of floating macrophytes (Eichhornia crassipes) inserted along one edge of the mesocosms. Treatment effects on microcrustacean density and community structure using taxonomic and functional classification approaches were assessed. There was a positive association between macrophyte presence and microcrustacean diversity for both diversity types, showing that the presence of macrophytes enhanced the niche availability for the microcrustacean community, likely through changes to resource diversity through habitat structure provision. In the presence of macrophytes, the abundance of species with the following feeding traits increased: burrowing, benthic habitat preference, and herbivore–detritivore and omnivore–carnivore trophic groups. Results showed that the species capable of using the niche offered by submerged macrophyte structures had benthic traits, enabling their co-existence with species possessing primarily pelagic traits. Using a functional approach, our study demonstrated that Eichhornia crassipes can structure microcrustacean communities and promote diversity, likely via increased habitat diversity, which enables the co-existence of species possessing different adaptations to acquiring resources available in the environment.
43
Vinyard, Gary L., Ray W. Drenner, Moshe Gophen, Utsa Pollingher, Dana L. Winkelman, and K. David Hambright. "An Experimental Study of the Plankton Community Impacts of Two Omnivorous Filter-Feeding Cichlids, Tilapia galilaea and Tilapia aurea." Canadian Journal of Fisheries and Aquatic Sciences 45, no. 4 (April 1, 1988): 685–90. http://dx.doi.org/10.1139/f88-082.
Full textAbstract:
We conducted laboratory selective grazing experiments and outdoor mesocosm experiments assessing impacts of two cichlids, Tilapia galilaea and Tilapia aurea, on plankton from Lake Kinneret, Israel. Laboratory feeding rates of both fish increased for larger particles, reaching maximum values for zooplankton and Peridinium cinctum. Tilapia galilaea had higher feeding rates on Peridinium elpatiewsky and on intermediate-sized nanoplankton. Outdoor mesocosm experiments examining fish impacts on plankton community structure included two 21-d spring and summer experiments of replicated 2 × 2 factorial design (T. galilaea × T. aurea). Both fish suppressed crustaceans and rotifers. In the spring, fish also suppressed chlorophyll concentration and the dominant phytoplankter P. cinctum. In the summer, when nanoplankton dominated the phytoplankton and the smaller P. elpatiewsky was the most abundant dinoflagellate, only T. galilaea suppressed Peridinium spp., while presence of T. aurea was associated with increased chlorophyll concentration. Overall, T. galilaea suppressed more and enhanced fewer nanoplankton taxa than did T. aurea. Production of each fish species was lowest when both species were together, suggesting potential competition for plankton resources.
44
Negreiros, Natalia Felix, Maria José dos Santos-Wisniewski, Renata Martins dos Santos, and Odete Rocha. "The influence of environmental factors on the seasonal dynamics and composition of Rotifera in the Sapucaí River arm of Furnas Reservoir, MG, Brazil." Biota Neotropica 10, no. 4 (December 2010): 173–82. http://dx.doi.org/10.1590/s1676-06032010000400023.
Full textAbstract:
Seasonal fluctuations in the dynamics of the plankton rotifer populations in an oligo-mesotrophic branch of a tropical reservoir were analyzed with respect to the possible influence of environmental conditions (physical, chemical and biological), with emphasis on biological interactions. Samples were taken monthly from August 2006 to July 2007. The well-defined climatic seasons were reflected in variations of the physical and chemical properties of the water. The zooplankton community consisted mainly of Rotifera, Cladocera and Copepoda, with occasional representatives of Chaoborus brasiliensis (Diptera), Ostracoda, Protozoa and Turbellaria. Rotifera was the dominant group in zooplankton community in 5 of the 12 months of the study and were represented by 35 taxa. Redundancy analysis between the rotifer population abundances and the set of environmental variables showed significant (p < 0.05) positive correlations with the chlorophyll a in the rainy season. In the dry period, predation was probably the environmental factor that had the strongest effect on rotifer populations; in particular, the density of the cyclopoid Thermocyclops decipiens showed significant (p < 0.05) negative correlations with many of the rotifer population abundances. In addition, analysis of the co-occurrence of different rotifer species indicated strong competitive interactions between populations, during the rainy period (p < 0.001). Among the biotic environmental factors analyzed, algal biomass had an important role during the rainy period and inter-rotifer competition was also significant in these months. It was probably that predation by the cyclopoid copepod Thermocyclops decipiens determined the structure and dynamics of the rotifer populations in the Sapucaí arm of the Furnas reservoir, during the dry period.
45
Doll, Jason C., and Stephen J. Jacquemin. "Incorporation of feeding functional group information informs explanatory patterns of long-term population changes in fish assemblages." PeerJ 9 (March 29, 2021): e11032. http://dx.doi.org/10.7717/peerj.11032.
Full textAbstract:
The objective of this study was to evaluate long term trends of fish taxa in southern Lake Michigan while incorporating their functional roles to improve our understanding of ecosystem level changes that have occurred in the system over time. The approach used here highlighted the ease of incorporating ecological mechanisms into population models so researchers can take full advantage of available long-term ecosystem information. Long term studies of fish assemblages can be used to inform changes in community structure resulting from perturbations to aquatic systems and understanding these changes in fish assemblages can be better contextualized by grouping species according to functional groups that are grounded in niche theory. We hypothesized that describing the biological process based on partial pooling of information across functional groups would identify shifts in fish assemblages that coincide with major changes in the ecosystem (e.g., for this study, shifts in zooplankton abundance over time). Herein, we analyzed a long-term Lake Michigan fisheries dataset using a multi-species state space modeling approach within a Bayesian framework. Our results suggested the population growth rates of planktivores and benthic invertivores have been more variable than general invertivores over time and that trends in planktivores can be partially explained by ecosystem changes in zooplankton abundance. Additional work incorporating more ecosystem parameters (e.g., primary production, etc.) should be incorporated into future iterations of this novel modeling concept.
46
Huss, Magnus, Jennifer G. Howeth, Julia I. Osterman, and David M. Post. "Intraspecific phenotypic variation among alewife populations drives parallel phenotypic shifts in bluegill." Proceedings of the Royal Society B: Biological Sciences 281, no. 1787 (July 22, 2014): 20140275. http://dx.doi.org/10.1098/rspb.2014.0275.
Full textAbstract:
Evolutionary diversification within consumer species may generate selection on local ecological communities, affecting prey community structure. However, the extent to which this niche construction can propagate across food webs and shape trait variation in competing species is unknown. Here, we tested whether niche construction by different life-history variants of the planktivorous fish alewife ( Alosa pseudoharengus ) can drive phenotypic divergence and resource use in the competing species bluegill ( Lepomis macrochirus ). Using a combination of common garden experiments and a comparative field study, we found that bluegill from landlocked alewife lakes grew relatively better when fed small than large zooplankton, had gill rakers better adapted for feeding on small-bodied prey and selected smaller zooplankton compared with bluegill from lakes with anadromous or no alewife. Observed shifts in bluegill foraging traits in lakes with landlocked alewife parallel those in alewife, suggesting interspecific competition leading to parallel phenotypic changes rather than to divergence (which is commonly predicted). Our findings suggest that species may be locally adapted to prey communities structured by different life-history variants of a competing dominant species.
47
Mills, Edward L., Robert O'Gorman, Joe DeGisi, Roy F. Heberger, and Robert A. House. "Food of the Alewife (Alosa pseudoharengus) in Lake Ontario before and after the Establishment of Bythotrephes cederstroemi." Canadian Journal of Fisheries and Aquatic Sciences 49, no. 10 (October 1, 1992): 2009–19. http://dx.doi.org/10.1139/f92-224.
Full textAbstract:
Diets and length–weight relationships of Lake Ontario alewife (Alosa pseudoharengus) in 1972 differed from those in 1988; the large cladoceran Bythotrephes cederstroemi colonized the lake during the mid-1980's. Micro-crustacean zooplankton were the dominant prey of alewife during April–October in 1972 and 1988. Although Bythotrephes was not found in 1988 net samples, it replaced other zooplankters in the alewife's diet. Typically, tailspines were the only part of Bythotrephes in alewife stomachs; their frequency was high in April–May, diminished rapidly in summer and was very low by fall. In spring 1988, alewife [Formula: see text] were in better condition than in spring 1972 and this may have been due to larger fish feeding more heavily on Bythotrephes. Variation in diet among widely separated sampling sites was due to differences in alewife abundance, stability of thermal structure, progress of zooplankton community development and distance to the mouth of the Niagara River (through which Bythotrephes probably enter the lake in summer and fall). In the Great Lakes, inter- and intralake differences in diet clearly exist, and these must be incorporated into models of alewife planktivory to gain an accurate understanding of energy flow between trophic levels.
48
Morley, N. J., and J. W. Lewis. "Consequences of an outbreak of columnaris disease (Flavobacterium columnare) to the helminth fauna of perch (Perca fluviatilis) in the Queen Mary reservoir, south-east England." Journal of Helminthology 84, no. 2 (September 8, 2009): 186–92. http://dx.doi.org/10.1017/s0022149x09990459.
Full textAbstract:
AbstractParasitism of fish in fully bunded storage reservoirs has rarely been studied, while the impact of a rapid decline in a fish population on its parasite fauna is poorly understood. The present paper investigates the helminth fauna of perch (Perca fluviatilis) over a 5-year period in the Queen Mary reservoir, a large (290 ha) completely artificial water storage impoundment, which forms a unique and challenging habitat for its resident fish population. After 3 years of study, the perch population suffered a significant reduction due to a disease outbreak caused by the pathogenic bacterium Flavobacterium columnare, ‘columnaris disease’, and the subsequent effects on the helminth fauna over the next 2 years are evaluated. Conditions in the reservoir favour the development of large populations of zooplankton, which act as intermediate hosts for the majority of helminths in the dominant perch community. The prevalence and intensity of helminth infections showed much variation over the period prior to the perch mortality. These were likely to be due to changes in the zooplankton biomass, which was exposed to biotoxins released from periodic algal blooms and the application of copper to control them. The outbreak of F. columnare resulted in a significant decrease in the size and condition coefficient of the perch population. Changes also occurred in the composition of helminth parasites, with many species demonstrating either an increase or decrease in infection levels. These changes may be partly associated with an increase in the zooplankton biomass and altered population structure, probably caused by a decrease in fish predation pressure, which would influence the parasite population dynamics, although other factors directly associated with changes in the perch population are also likely to be influential. The long-term affects on the levels of helminth infections in the fish and associated intermediate hosts in the Queen Mary reservoir are discussed.
49
Volkov, Anatoly F. "Elementary trophic ecology of pacific salmons in the Bering Sea. Species and regional differences. Provision with food in different environments." Izvestiya TINRO 187, no. 4 (December 30, 2016): 162–86. http://dx.doi.org/10.26428/1606-9919-2016-187-162-186.
Full textAbstract:
The final issue in the series of studies on trophic ecology of pacific salmons in the Bering Sea conducted by planktonologists of Pacific Fish. Res. Center (TINRO) for NPAFC. Salmons dwell in the upper epipelagic layer and feed mainly in the daytime by large-sized zooplankton that is more abundant in the upper pelagic layer as compared with the lower pelagic layer in summer-fall season. The zooplankton and nekton species dominant in the salmon diet are determined on the base of 8,000 plankton samples and 45,000 samples of salmon stomachs. Two periods with different environments are revealed in the Bering Sea in the early 21 century: the relatively warm period of 2000-2006 and the relatively cold period of 2007-2012. The regime shift between them affected the plankton community and trophic ecology of salmon, though not by means of water cooling directly but presumably because of the water circulation change. Food composition is determined for each size group of salmons in both periods, by biostatistical areas and bathymetric ranges. Zooplankton grazing by salmons increased significantly in all areas during the cold period, whereas the nekton grazing decreased, but their total consumption did not change much. Transition to the next warm period since 2013 does not affect negatively to the salmon food base; their diet changes significantly but within the list of preferable species. Feeding intensity of pink, chum, and sockeye salmons was similar in any period, as well as in the 2014-2015, food deficit was never observed. The salmons show a great plasticity in feeding: in general, their diet corresponds to the structure of plankton community, though the portion of nekton increases with the age. Large-sized salmons consume a large-sized prey and need more time for its complete digestion, so there is necessary to apply reduction coefficients in calculation of their daily food rations. Nutritional needs of all salmon stocks are estimated for summer-fall season and offered as a guideline for evaluation their load on the food base and their food security for certain spatial and temporal circumstances.
50
Décima, M., and MR Landry. "Resilience of plankton trophic structure to an eddy-stimulated diatom bloom in the North Pacific Subtropical Gyre." Marine Ecology Progress Series 643 (June 11, 2020): 33–48. http://dx.doi.org/10.3354/meps13333.
Full textAbstract:
We investigated the response of an open-ocean plankton food web to a major ecosystem perturbation event, the Hawaiian lee cyclonic eddy Opal, using compound-specific isotopic analyses of amino acids (CSIA-AA) of individual zooplankton taxa. We hypothesized that the massive diatom bloom that characterized Opal would lead to a shorter food chain. Using CSIA-AA, we differentiated trophic position (TP) changes that arose from altered transfers through protistan microzooplankton, versus metazoan carnivory, and assessed the variability at the base of the food web. Contrary to expectation, zooplankton TPs were higher in the eddy than in ambient control waters (up to 0.8 trophic level), particularly for suspension feeders close to the food-web base. Most of the effect was due to increased trophic transfers through protistan consumers, indicating a general shift up, not down, of grazing and remineralization in the microbial food web. Eucalanus sp., which was 15-fold more abundant inside compared to outside of the eddy, was the only taxon observed to be a true herbivore (TP = 2.0), consistent with a high phenylalanine (Phe) δ15N value indicating feeding on nitrate-fueled diatoms in the lower euphotic zone. Oncaea sp., an aggregate-associated copepod, had the largest (1.5) TP difference, and lowest Phe δ15N, suggesting that detrital particles were local hot spots of enhanced microbial activity. Rapid growth rates and trophic flexibility of protistan microzooplankton apparently allow the microbial community to reorganize to bloom perturbations, as microzooplankton remain the primary phytoplankton grazers—despite the dominance of large diatoms—and are heavily preyed on by the mesozooplankton.