Differential temperature sensitivity of two cladoceran species to resource variation during a blue-green algal bloom

1986 ◽  
Vol 64 (8) ◽  
pp. 1739-1744 ◽  
Author(s):  
Stephen T. Threlkeld
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Green Algae ◽  
Growth Rates ◽  
Algal Bloom ◽  
Zooplankton Community Structure ◽  
Lake Texoma ◽  
Blue Green Algae ◽  
Green Algal ◽  
First Reproduction

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.

Influence of Water Temperature and Nitrogen to Phosphorus Ratios on the Dominance of Blue-Green Algae in Lake St. George, Ontario

1987 ◽  
Vol 44 (3) ◽  
pp. 598-604 ◽  
Author(s):  
D. J. McQueen ◽  
D. R. S. Lean
Keyword(s):  
Green Algae ◽  
Algal Bloom ◽  
Inorganic Nitrogen ◽  
Data Set ◽  
Blue Green Algae ◽  
Green Algal ◽  
Influence Of Water ◽  
Total Inorganic Nitrogen ◽  
Explained Variation ◽  
Algal Composition

Data collected at Lake St. George, Ontario, over five summers spanning a period of 13 yr showed that there was no correlation between percent blue-green algal composition and the ratio of total nitrogen (TN) to total phosphorus (TP), However, percent blue-green algae was positively correlated with temperature and negatively correlated with nitrate nitrogen (NO3-N), total inorganic nitrogen (TIN), and the ratio of NO3-N:TP. Multiple correlations involving percent blue-green algae (dependent variable) with respect to temperature, in combination with one of NO3-N, TIN, NO3-N:TP, or TIN:TP, were also significant. In all cases, temperature effects accounted for most of the explained variation. The strongest correlation was found for the multiple regression involving percent blue-green algae versus temperature and the NO3-N: TP ratio. The pattern that emerged from the Lake St. George data set was that when temperature exceeded 21 °C and the ratio of NO3-N:TP was below 5:1, the likelihood of a blue-green algal bloom was high. When temperature was below 21 °C and NO3-N:TP exceeded 5:1, blue-green blooms never occurred.

scholarly journals Interaction between simulated dense Scenedesmus dimorphus (Chlorophyta) bloom and freshwater meta-zooplankton community

2018 ◽  
Vol 77 (2) ◽  
Author(s):  
Zengling Ma ◽  
Hengguo Yu ◽  
Ronald Thring ◽  
Chuanjun Dai ◽  
Anglv Shen ◽  
...  
Keyword(s):  
Community Structure ◽  
Green Algae ◽  
Aquatic Ecosystems ◽  
Algal Blooms ◽  
Algal Bloom ◽  
Photochemical Efficiency ◽  
Zooplankton Community ◽  
Post Inoculation ◽  
Zooplankton Community Structure ◽  
Scenedesmus Dimorphus

Algal bloom has been a subject of much research, especially the occurrence of blue-green algae (cyanobacteria) blooms and their effects on aquatic ecosystems. However, the interaction between green algae blooms and zooplankton community was rarely investigated. In the present study, the effects exerted by Scenedesmus dimorphus (green alga) bloom on the community structure of zooplankton and the top-down control of the bloom process mediated by the zooplankton were evaluated using a series of laboratory cultures. The results showed that a dense S. dimorphus bloom could change the zooplankton community structure by decreasing its diversity indices, leading to the enrichment of a particular zooplankton species, Brachionus calyciflorus. In the presence of mixed species of zooplankton, the density of S. dimorphus in the culture was decreased as determined by a change in total chlorophyll a (Chl a) concentration, which was about 200 μg L-1 lower than that of the zooplankton-free culture. Furthermore, the number of species belonging to Cladocera, Copepoda and Rotifera all decreased, with all the cladocerans disappeared in the co-culture within 2 weeks of culturing, while the density of rotifers increased from 818 (±243) ind L-1 at the time of inoculation to 40733 (±2173) ind L-1 on the 14th day post-inoculation. Grazing of S. dimorphus by the rotifer B. calyciflorus neutralized its growth, and the gradual increase in B. calyciflorus density eventually led to the collapse of the bloom. Furthermore, grazing by B. calyciflorus also led to a decrease in the maximal photochemical efficiency (Fv/Fm) of photosystem II (PSII). The combined changes occurring in the zooplankton community structure during the process of S. dimorphus bloom and the negative effects of grazing on algal growth, morphology and photosynthetic activities confirmed the key role of zooplankton in the control of algal bloom. The results of the study therefore indicated that dense algal blooms caused by non-toxic algae could still remain a threat to aquatic ecosystems.

scholarly journals PHARMACEUTICAL POTENTIAL OF LABORATORY GROWN CULTURES OF BLUE-GREEN ALGAE: A COMPREHENSIVE REVIEW AND FUTURE POSSIBILITIES

2021 ◽  
Vol 9 (5) ◽  
pp. 543-571
Author(s):  
Ritu Chauhan ◽  
◽  
Abhishek Chauhan ◽  
Ashutosh Tripathi ◽  
Anuj Ranjan ◽  
...  
Keyword(s):  
Green Algae ◽  
Bioactive Compounds ◽  
Current Knowledge ◽  
Biological Activities ◽  
Biologically Active ◽  
Primary And Secondary Metabolites ◽  
Blue Green Algae ◽  
Green Algal ◽  
Algal Group ◽  
Diverse Application

COVID-19 pandemic has taught the world researchers the urgent need for new sources and novel pharmaceuticals not only for existing diseases but also for both seasonal epidemics and future pandemics. Pharmaceutical drug discoveries for the past fifty years depended deeply on the procedure of empirical transmission of a huge number of pure bioactive compounds to provide new leads. The screening of extracts or isolating compounds is a common way to discover novel biologically active molecules. Most of the valuable Blue-Green algal metabolites are concentrated in their biomass. For existence in nature, Blue-Green algae (BGA) secrete and contain various organic substances like proteins, fatty acids, vitamins, pigments, primary and secondary metabolites, and these compounds are explored for potential biological activities such as antibacterial, antifungal, antiviral (including the anti-SARS-CoV-2 virus that causes COVID-19), anticancer, antioxidant, antidiabetic, protease inhibitory activity, anti-inflammatory activity, etc. Due to their diverse application, pharmaceutical companies have shown commercial interest in the Blue-green algal group for the discovery and development of novel molecules to combat deadly diseases for the benefit of society and mankind. The current review paper highlights and discusses the diverse pharmaceutical potential of laboratory-grown cultures of BGA along with comprehensive and current knowledge on bioactive compounds discovered by researchers globally.

An Evaluation of RNA–DNA Ratio as a Measure of Long-Term Growth in Fish Populations

1973 ◽  
Vol 30 (2) ◽  
pp. 195-199 ◽  
Author(s):  
Terry A. Haines
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Growth Rates ◽  
Population Growth Rate ◽  
Environmental Changes ◽  
Age Distribution ◽  
Smallmouth Bass ◽  
Fish Populations ◽  
Population Growth Rates

The value of RNA–DNA ratio as a measure of long-term growth of fish populations under semi-natural conditions and when subjected to environmental manipulations was determined. Populations of carp and smallmouth bass of known age distribution were established in artificial ponds maintained at two fertility levels. After 15 months, population growth rates (as percent increase in weight) and RNA–DNA ratios of muscle tissue from selected fish were measured. Each species exhibited a range of population growth rates. The relation between population growth rate and individual fish RNA–DNA ratio for each species was significant. When reproduction occurred, the relation was not significant unless young-of-the-year fish were excluded from population growth rate calculations. Age of fish was also found to have an important effect on RNA–DNA ratio, with the ratio being higher in younger fish.RNA–DNA ratio can be a reliable indicator of long-term population growth in fish when population age structure is known and recruitment is controlled. The method has potential for use in detecting response to environmental changes before growth rate changes become severe.

scholarly journals Breeding transients in capture–recapture modeling and their consequences for local population dynamics

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Daniel Oro ◽  
Daniel F. Doak
Keyword(s):  
Growth Rate ◽  
Population Dynamics ◽  
Population Growth ◽  
Population Growth Rate ◽  
Local Population ◽  
Environmental Stochasticity ◽  
Adult Survival ◽  
Local Survival ◽  
First Reproduction ◽  
Capture Recapture

Abstract Standard procedures for capture–mark–recapture modelling (CMR) for the study of animal demography include running goodness-of-fit tests on a general starting model. A frequent reason for poor model fit is heterogeneity in local survival among individuals captured for the first time and those already captured or seen on previous occasions. This deviation is technically termed a transience effect. In specific cases, simple, uni-state CMR modeling showing transients may allow researchers to assess the role of these transients on population dynamics. Transient individuals nearly always have a lower local survival probability, which may appear for a number of reasons. In most cases, transients arise due to permanent dispersal, higher mortality, or a combination of both. In the case of higher mortality, transients may be symptomatic of a cost of first reproduction. A few studies working at large spatial scales actually show that transients more often correspond to survival costs of first reproduction rather than to permanent dispersal, bolstering the interpretation of transience as a measure of costs of reproduction, since initial detections are often associated with first breeding attempts. Regardless of their cause, the loss of transients from a local population should lower population growth rate. We review almost 1000 papers using CMR modeling and find that almost 40% of studies fitting the searching criteria (N = 115) detected transients. Nevertheless, few researchers have considered the ecological or evolutionary meaning of the transient phenomenon. Only three studies from the reviewed papers considered transients to be a cost of first reproduction. We also analyze a long-term individual monitoring dataset (1988–2012) on a long-lived bird to quantify transients, and we use a life table response experiment (LTRE) to measure the consequences of transients at a population level. As expected, population growth rate decreased when the environment became harsher while the proportion of transients increased. LTRE analysis showed that population growth can be substantially affected by changes in traits that are variable under environmental stochasticity and deterministic perturbations, such as recruitment, fecundity of experienced individuals, and transient probabilities. This occurred even though sensitivities and elasticities of these parameters were much lower than those for adult survival. The proportion of transients also increased with the strength of density-dependence. These results have implications for ecological and evolutionary studies and may stimulate other researchers to explore the ecological processes behind the occurrence of transients in capture–recapture studies. In population models, the inclusion of a specific state for transients may help to make more reliable predictions for endangered and harvested species.

Volatile Compounds of the Cyanophyceae – A Review

1983 ◽  
Vol 15 (6-7) ◽  
pp. 181-190 ◽  
Author(s):  
George P Slater ◽  
Vivian C Blok
Keyword(s):  
Fatty Acids ◽  
Volatile Compounds ◽  
Organic Compounds ◽  
Green Algae ◽  
Aquatic Organisms ◽  
Blue Green Algae ◽  
Green Algal

A relationship between blue-green algae and off-flavours in water was reported as early as 1883. Continuing research has shown that two metabolites, geosmin and methylisoborneol are major contributors to unpalatable flavours in water and aquatic organisms. Many instances of the co-occurrence of these two compounds and dense blooms of blue-green algae have been recorded. Cultures of Anabaena, Lyngbya, Osciiiatoria, and Sympioca species have been shown to produce geosmin or methylisoborneol while blooms of Aphanizomenon, Anabaena, Microcystis, Oscillatoria, and Gomphosphaeria have been found in water containing geosmin or the odour of this compound. Actinomycetes have also been shown to produce these two compounds. In addition to geosmin and methylisoborneol, there is evidence that several other blue-green algal metabolites contribute to aquatic taste and odour problems. Among them is β-cyclocitral which has a distinctive tobacco flavour. Blue-green algae produce a variety of organic compounds including hydrocarbons, fatty acids, aromatics, ketones, terpenoids, amines and Sulfides which could contribute to the over-all flavour of water and aquatic organisms.

Phosphate uptake by blue-green algae during an algal bloom

1984 ◽  
Vol 22 (1) ◽  
pp. 195-199
Author(s):  
Gernot Falkner ◽  
Peter Strasser ◽  
Dietmar Graffius
Keyword(s):  
Green Algae ◽  
Algal Bloom ◽  
Phosphate Uptake ◽  
Blue Green Algae

Growth rate observation from the moss-built Checa travertine terrace, central Spain

1986 ◽  
Vol 123 (3) ◽  
pp. 279-286 ◽  
Author(s):  
Ruud Weijermars ◽  
Carla W. Mulder-Blanken ◽  
Jaap Wiegers
Keyword(s):  
Growth Rate ◽  
Surface Area ◽  
Green Algae ◽  
Central Spain ◽  
Blue Green Algae ◽  
Artificial Surfaces ◽  
Depositional Rate ◽  
Bryum Pseudotriquetrum ◽  
Time Required

AbstractIn situ observations of fossil and living specimens of the calcicolous mosses Bryum pseudotriquetrum, Cratoneuron commutatum and Catoscopium nigritum revealed very fast calcite depositional rates. Rhythmic layering in the fossil mosses corresponding with the seasonal climatic cycle suggests that the moss curtain occupied by these three mosses maintains the deposition of spongeous travertine layers at a mean rate of 4 cm a−1. A mean depositional rate of 4.2 cm a−1 may be calculated from measurements of the loss of bicarbonate from the springwater after it percolated through the moss curtain. These rates suggest that the 8 m high travertine terrace of Checa with a surface area of 800 m2 did not exist two millennia ago.Mosses could be put to man's use for creating natural overgrowths on artificial surfaces, an idea based on an allusion by Wallner. He observed that the thread-forming, blue-green algae Vaucheria builds travertine deposits at an annual rate of 0.7–1.4 cm. We observed that the mosses Cratoneuron commutatum and Bryum pseudotriquetrum may form spongeous travertine layers at respective maximum rates of 11 and 14 cm a−1. This would reduce the time required to build natural overgrowths on artificial objects to a practical period of months.

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