Quantity Of Plankton Research Articles

Temperature-dependent metabolic consequences of food deprivation in the European sardine.

Aquatic ecosystems can exhibit seasonal variation in resource availability and animals have evolved to cope with the associated caloric restriction. During winter in the NW Mediterranean Sea, the European sardine Sardina pilchardus naturally experiences caloric restriction due to a decrease in diversity and quantity of plankton. Ongoing global warming has, however, had deleterious effects on plankton communities such that food shortages may occur throughout the year, especially under warm conditions in the summer. We investigated the interactive effects of temperature and food availability on sardine metabolism, by continuously monitoring whole-animal respiration of groups of control (fed) and food-deprived sardines over a 60-day experiment in winter (12°C) or summer (20°C) conditions under natural photoperiod. In addition, we measured mitochondrial respiration of red muscle fibres, biometric variables and energy reserves, of individuals sampled at 30 and 60 days. This revealed that winter food deprivation elicits energy saving mechanisms at whole animal and cellular levels by maintaining a low metabolism to preserve energy reserves, allowing high survival. By contrast, despite energy saving mechanisms at the mitochondrial level, whole animal metabolic rate was high during food deprivation in summer, causing increased consumption of energy reserves at the muscular level and high mortality after 60 days. Furthermore, a 5-day refeeding did not improve survival and mortalities actually continued, suggesting that long-term food deprivation at high temperatures caused profound stress in sardines that potentially impaired nutrient absorption.

Stability switch and Hopf bifurcations for a diffusive plankton system with nonlocal competition and toxic effect

<abstract><p>Since the distribution of plankton is always uneven, the nonlocal phytoplankton competition term indicates the spatial weighted mean of phytoplankton density, which is introduced into the plankton model with toxic substances effect to study the corresponding dynamic behavior. The stability of the positive equilibrium point and the existence of Hopf bifurcations are discussed by analysing the distribution of eigenvalues. The direction and stability of bifurcation periodic solution are researched based on an extended central manifold method and normal theory. Finally, spatially inhomogeneous oscillations are observed in the vicinity of the Hopf bifurcations. Through numerical simulation, we can observe that the system without nonlocal competition term only generates homogeneous periodic solution, and inhomogeneous periodic solution will produce only when both diffusion and nonlocal competition exist simultaneously. We can also see that when the toxin-producing rate of each phytoplankton is in an appropriate range, the system with nonlocal competition generates a stability switch with inhomogeneous periodic solution, when the value of time delay is in a certain interval, then Hopf bifurcations will appear, and with the increase of time delay, the quantity of plankton will eventually become stable.</p></abstract>

Ecological Potentiality of Plankton: A Perspective on Nutrition, Toxicity and Bio-Indication

The base of aquatic energy is initiated and concreted by plankton such as primary photosynthetic algae and consequently their immediate secondary grazers as zooplankton. The nutritional features of algae or phytoplankton are controlled by aquatic nutrients (e.g. nitrogen, phosphorus, silica and other essential minerals). Moreover, the biochemical content of zooplankton reflects their diet profiles (e.g. bacteria and algae). The promising and sustainable fisheries prospects are crucially subjective by nutritional quality and quantity of plankton (e.g. algal bloom). Additionally, both algae and zooplankton are efficient as auspicious biological tools for indicating the aquatic environments.

Latitudinal and Cross-Shelf Patterns of Size, Age, Growth, and Mortality of a Tropical Damselfish Acanthochromis polyacanthus on the Great Barrier Reef

Patterns of age and growth of a sedentary damsel fish Acanthochromis polyacanthus were tested over a latitudinal range of approximately 10 degrees (1200 km) on the Great Barrier Reef (GBR), Australia. Within latitudes, these patterns were also compared on reefs in distance strata (inner, mid, and outer) across a continental shelf that ranged in width from 52 to 128 km. Although variation in length-max (SLMAX), growth, age-max (AMAX), and the von Bertalanffy metrics of Linf and K were found within and among latitudes, the greatest variation in some demographic characteristics was found among distance strata across the shelf regardless of latitude. Fish were always relatively smaller at inner shelf reefs and grew more slowly when compared to mid and outer shelf reefs; this was true regardless of the color morph of fish. The oldest fish collected was 11 years old, and there was no consistent variation in age-max among distances from shore. On outer reefs, there was a negative linear relationship with age-max and latitude. This “tropical gradient” of age only explained 34% of the variation; furthermore, this was not found when only the oldest group of fish was considered (top 10%). Fish only reached an age-max of six years on the southernmost reefs. There was a trend for a smaller Linf with latitude but it was not significant and Linf did not vary predictably with water temperature. The sampling of marine protected areas (MPAs) and fished zones did not confound the resultant patterns in that fish were not consistently larger or older in MPAs or fished zones. Instantaneous mortality rates were 0.245–0.685; they were highest at inner reefs and also showed no consistent MPA-related patterns. Our study suggested that the mid and outer shelf waters of the GBR appeared best suited for growth of A. polyacanthus. In conclusion, the position on continental shelves dominated other geographical patterns and needs to be considered in spatial models of growth. We suggest that local environmental conditions such as turbidity and the quality and quantity of plankton likely have a strong influence on distance across the shelf-based demographic patterns of planktivores.

Mercury concentration variability in the zooplankton of the southern Baltic coastal zone

Being a toxic element, mercury is introduced to the human organism through the consumption of fish and seafood, which in turn often feed on zooplankton. The bioaccumulation of Hg by zooplankton is an important factor influencing the magnitude of the mercury load introduced with food into the predator organism. Therefore the present article attempts to identify the processes and factors influencing Hg concentration in the zooplankton of the coastal zone, an area where marine organisms – an attractive food source for humans – thrive. This is particularly important in areas where climate changes influence the species composition and quantity of plankton. The studies were carried out on three test sites in the coastal zone of the southern Baltic Sea in the period from December 2011 to May 2013. The obtained results show that the shorting of the winter season is conducive to Hg increase in zooplankton and, consequently, in the trophic chain. High mercury concentrations were measured in genus Synchaeta and Keratella when Mesodinium rubrum were predominant in phytoplankton, while other sources of this metal in the plankton fauna were epilithon, epiphton and microbenthos. This is of particular importance when it comes to sheltered bays and estuaries with low water dynamics.

Effects of Biofloc on Plankton Abundance in the Water

This study was conducted to evaluate the effects of biofloc on the species and quantity of plankton in pond water. There were four treatments in the experiment: the control, no supplementation; treatment I, pond water supplemented with glucose; treatment II, pond water supplemented with both glucose and Bacillus subtilis; and treatment III, pond water supplemented with Bacillus subtilis only. Water quality, plankton, and biofloc formation were monitored every five days. Results showed that biofloc formation was enhanced by adding glucose to the pond water. The addition of glucose together with Bacillus subtilis shortened the formation time of mature bioflocs by about five days than the supplementation with glucose only. In ponds supplemented with glucose and those supplemented with glucose + bacillus, the ammonia nitrogen, and nitrite nitrogen content in the water column decreased, and the number of cyanobacteria and green algae were significantly inhibited, while the number of zooplankton such as Rotatoria increased during the experimental period.

Effects of Biofloc on Plankton Abundance in the Water

This study was conducted to evaluate the effects of biofloc on the species and quantity of plankton in pond water. There were four treatments in the experiment: the control, no supplementation; treatment I, pond water supplemented with glucose; treatment II, pond water supplemented with both glucose and Bacillus subtilis; and treatment III, pond water supplemented with Bacillus subtilis only. Water quality, plankton, and biofloc formation were monitored every five days. Results showed that biofloc formation was enhanced by adding glucose to the pond water. The addition of glucose together with Bacillus subtilis shortened the formation time of mature bioflocs by about five days than the supplementation with glucose only. In ponds supplemented with glucose and those supplemented with glucose + bacillus, the ammonia nitrogen, and nitrite nitrogen content in the water column decreased, and the number of cyanobacteria and green algae were significantly inhibited, while the number of zooplankton such as Rotatoria increased during the experimental period.

The Crustcea and Rotifera in the pond near «Piramida» shopping mall (Samara) in 2013

The composition and population sizez of the Crustacea and Rorifera species were studied in an urban pond after its melioration. 30 Rotifera species (52 species before melioration) and 20 Crustacea species (33 species before melioration) were found in 2013. Brachionidae, Synchaetidae и Asplanchnidae remain dominant in the Rotifera community. Cyclopoidae were dominant in the Crustacea community (Daphniidae dominated before melioration). The quantity of Bosminidae и Chydoridae considerably increased. On the whole the quantity of animal plankton decreased by 15% in 2013. In 2010 rises of the quantity were observed twice, in June and in August; in 2013 there was only one rise of the quantity of the plankton in July. The number of female individuals with eggs increased. The pond refers to the -mesosaprobic zone, the level of contamination in terms of saprobity indicators decreased. The Shannon index of species diversity was calculated. Removal of macrophytes caused decrease of littoral species and growth of plankton invertebrates. The hydrochemical analysis revealed the excess of the maximum permissible concentration of BOC₅, АSАS, Cu, Fe and Zn.

PLANKTON WYBRANYCH OCZEK WODNYCH PUSZCZY BIAŁOWIESKIEJ

Bialowieza Forest is the natural habitat of many rare species of green plants, animals and fungi. For centuries, it has been a unique place for developing environmental processes. The water ponds are the wildlife habitat for many organisms, whose lives depend on aquatic environments. Protected species of green plants and animals also live in the water ponds. The aim of this research was to determine the species and quantity of plankton which are present in Bialowieza Forest’s water ponds. The presence of different species of plankton proved the presence of minimal organic pollution. It was noticed that the primary producers dominated over the other organisms, which confirmed high mineralisation. The water ponds should continue to be monitored, as they are responsible for biodiversity within the Bialowieza Forest area and they are the best place to settle for many species which are characteristic for swamps and small sources of water.

The changed ecosystem of the black sea and its impact on anchovy fisheries

As a result of eutrophication caused by increased nutrient input via major northwestern rivers during the last few decades, the Black Sea ecosystem has been subject to extreme changes in recent years. Abnormal changes due to altered nutrient balance were reflected in the qualitative and quantitative composition of phytoplankton and zooplankton. The increase observed in the quantity of plankton was probably responsible for the rise of Turkish anchovy catches observed over the last few decades. However since 1988, the Black Sea has been invaded by a voracious zooplankton predator, the ctenophore Mnemiopsis leidyi which was accidentally introduced into this sea from the northwest Atlantic. This mass occurrence of Mnemiopsis appears to be one of the most important reasons for the sharp decrease of anchovy and other pelagic fish stocks in the Black Sea. By October 1997, new ctenophore Beroe ovata has appeared in shallow waters of the Black. Species of genus Beroe almost exclusively feed on other ctenophores and feeding interaction within ctenophores form an ecological feed-back system which also affects other compartments of the planktonic community.

Ultrastructural Changes in Gill Epithelia of a Yellowtail, Seriola quinqueradiata, Exposed to Sea Bloom

Surface structures of the gill epithelia of a yellowtail, Seriola quinqueradiata were observed with a scanning electron microscope after ex-posure to sea bloom. The fish was on the verge of death 45 min after exposure in a circuit tank containing a quantity of plankton, including Gymnodinium. Morphological changes in the gill epithelia of the primary and secondary lamellae were observed on the afferent side. Pavement cells of the afferent side were swollen remarkably, but cells on the efferent side were intact. Chloride and mucous cells with many cellular extensions appeared in the epithelia of the afferent edge of the primary lamellae. Chloride cells were found on the interlamellar space of the secondary lamellae as well. These chloride and mucous cells, however, could not be seen clearly on gill filaments exposed to normal sea water.The significance of morphological changes due to lower salinity and their relation to the toxic effects of plankton are discussed.

The thermal springs of Bakreswar, India physico-chemical conditions, Flora and Fauna.

The physico-chemical characteristics as well as floristic and faunistic life of the seven thermal springs and one cold spring of Bakreswar, West Bengal form the basis of this paper. A compendium pertaining to the origin, geology and morphometry of these springs has been incorporated in brief. The temperature of the thermal springs remained almost constant over the past two decades and the location of the fissures of the springs is unchanged. On the basis of temperature these thermal springs are grouped into “acrothermal” and “euthermal”. The water of all the springs was alkaline with a pH between 7.4 and 9.2 No carbon dioxide was detected during the period of study. Absence of nitrite and traces of nitrate are characteristic features of these springs. The variation of colour of the water may be related to the presence of algal mats at the bottom of the springs. The quantity of plankton was maximal and minimal in thermal springs having highest and lowest temperature respectively. Oscillatoria sp., Navicula sp., Cyclotella sp. and Tetraedron sp. were noted at temperatures between 26° C and 51° C. It is a new record from India that diatoms like Navicula sp. and Cyclotella sp. can survive in the temperature range of 43–51° C. The thermophilic nematode, Tobrilus sp., Cyclops sp., Nauplius larvae, and Lecane sp. were recorded from Swetganga with a maximum temperature of 44° C. The mechanism of thermophily of the organisms is discussed in brief.

Distribution and ecology of the pelagic hydromedusae, siphonophores and ctenophores of the Barents Sea, based on perennial plankton collections

The evaluation of more than 10,000 samples of plankton, taken at standard stations from 1953 to 1960 in the Barents Sea, made it possible to supplement considerably the species list of medusae, siphonophores, and ctenophores, and to revise some ecological and biogeographical characteristics of many of them. Quantitative data, assembled over many years, on the occurrence of the above-mentioned groups, demonstrated the impossibility of using the vast majority of representatives of this fauna as biological indicators. During the very warm year of 1960, reproductively and vegetatively cold-adapted forms produced the same population increase as the thermophilic forms. The change in thermal conditions influenced these animals indirectly via a favourable biotic situation due to a prolongation of the nutrition period. The capability to vary the number of eggs, timing, rates and types of reproduction, to withstand long periods of starvation, etc., facilitates a flexible synchronization of the population dynamics of these pelagic predators with the quantity of plankton used for nutrition. The same properties stipulate the possibility of seasonal and annual meandering in regard to the boundaries of the water areas occupied.

A quantitative and qualitative study of the plankton of Alexandria Waters

Monthly observations on composition and quantity of plankton together with hydrographical conditions showed the following: (1) An abrupt drop in salinity occurs in September, accompanied by a considerable increase in silicate as a result of mixing with Nile waters. Phosphate shows a winter maximum and becomes exhausted after the Nile bloom. (2) A massive increase in phytoplankton production of exceptional amplitude in the Mediterranean follows the Nile flood in September–October. It is due to Chaetoceros socialis, Skeletonema costatum, Hemiaulus sinensis. A smaller early spring rise also occurs. (3) Small copepods, tintinnids and larvae of bottom animals are the main zooplankton organisms. Their periodic increases are responsible for the great rises of spring and early summer associated with a fall in phytoplankton.

Indices of Productivity in British Columbia Lakes

The relation between physical and chemical indices of production and standard crops of plankton, bottom fauna and fish was examined in 100 British Columbia lakes. A significant increase in plankton and fish quantities with increase in total dissolved solid content of lake waters was demonstrated and a similar relationship suggested for bottom fauna. Although the general form of the relationship between mean depth and plankton, and between bottom fauna and fish quantity, suggested a hyperbolic curve with larger quantities in lakes of low mean depth, the only generalization which seemed justified was that quantities of fauna from lakes of great mean depth were never as high as those found in some lakes of low mean depth. No significant relation was found between intensity and length of growing season and quantities of plankton, bottom fauna or fish, although a significant relationship was demonstrated between summer epilimnion temperature and plankton.In a multiple regression analysis using all lakes the predominance of total dissolved solids over mean depth in affecting summed indices of lake fauna was shown. However for lakes in the southern interior plateau, one of the 9 regions distinguished in British Columbia, no significant relation could be demonstrated between mean depth or total dissolved solids and summed indices of fauna or plankton alone. Thus total dissolved solid content of the water appeared to be the most important factor in determining the general level of productivity in lakes studied throughout the province, although within a region neither total dissolved solids nor mean depth could be used either singly or together to predict plankton, bottom fauna or fish quantities.

プラントクンの組成及量の時間的變化に就て

プラントクンの組成及量の時間的變化に就て

溜池に於けるPlanktonの出現に就て

1. I observed the seasonal variation in species and quantity of plankton appeared in 3 irrigation ponds, O-ike, Sin-ike and Asama-ike, from March to September 1947. 2. The numbers of species of phytoplankton and zooplankton are almost equal: about 67 species in O-ike, 60 in Sin-ike, 45 in Asama-ike. 3. Productivity of plankton is greatest in Sin-ike, and smallest in Asama-ike. The largest number observed was 4828/l in June in Sin-ile, 832/l in September in O-ike, 795/l in April in Asama-ike, 4. Phytoplankton appeared much in Spring and Autumnin Sin-ike and O-ike, but in Asama-ike in Spring only.

Quality and Quantity of Plankton in the South End of Lake Michigan in 1942

Quality and Quantity of Plankton in the South End of Lake Michigan in 1942

Observations on the Fatty Constituents of Marine Plankton

ABSTRACT Collections of phyto- and zooplankton made off the Isle of Man were examined for vitamin content, and for chemical and biological characteristics. The important species entering into the composition of the plankton are noted, and a new method of estimating plankton catches is described. Figures which represent the numbers of a species present in a given quantity of plankton are translated into figures representing the volume occupied by that species. Comparisons are drawn between the numerical and volumetric estimations of the various zooplankton species. The phytoplankton catches taken in May showed a fairly uniform composition throughout the collecting period, species of the genera Chaetoceros and Lauderia forming more than 90 per cent, of the material. The zooplankton taken in July consisted mainly of Copepoda. The catches were of two types : those having a higher percentage of Acartia, Calanus copepodid stages IV and III, and the Peridinian Ceratium ; and those containing less of these but rich in the adult and other stages of Calanus finmarchicus. By the use of curves correlating length and volume, measurements of important species are translated into factors representing numbers per c.c.; application of these factors converts the numerical estimation of a species into an estimation in terms of volume. The numerical and volumetric estimations of various species in four separate groups of plankton are compared and the yield of oil from each group is also recorded. The volumetric method conveys a significantly different picture of the plankton than is to be gained from the numerical method alone. Calanus finmarchicus is shown to constitute a relatively larger part of the plankton than other more numerous but smaller species and likewise its adult or sub-adult stages than its earliest copepodid stages. The correspondence of a good oil yield with those groups having a high Calanus content is held to be suggestive of a possible correlation between the two. Chemical and biochemical analyses of planktonic organisms by other investigators are reviewed and their results compared with those obtained during the present work. The rôle of plankton organisms in the nutrition of various other organisms is discussed.

Notes on the Plankton observed at Plymouth during June, July, August and September, 1892

The absence of systematic records showing the variations of the floating fauna and flora, or plankton, of the Plymouth waters is much to be regretted. My observations on the amount of animal and plant life suspended in the sea from the surface to the bottom would show that in comparison with similar observations made elsewhere, the quantity of plankton in this locality was during the past summer surprisingly small. The absence of data upon which comparisons could be based between the state of the water in this season and that obtaining in former years is all the more to be deplored because the present season has in many respects been a remarkable one. In the first place, the Plymouth mackerel fishery has so far been a complete failure; it has further been found that dog-fishes (both Scyllium and Acanthias) were not obtainable during June and July; and lastly, Aurelia aurita, which in summer is usually common, was extremely scarce in the Sound and tidal waters of Plymouth. If my Burmise that the amount of plankton was for the locality exceptionally small proves correct, then these three salient instances of scarcity of animals which are directly or indirectly dependent on the plankton for their food will suffice to show the importance of a series of more or less continuous observations on the physical and biological condition of the inshore and Channel waters. Were accurate information on these points available, it would in all probability enable us to explain, and we might even in time be able to foresee, the occurrence of so important an event as the exceptionally sporadic appearance of the mackerel in 1892.