Distribution and Abundance of Planktonic Crustacea in Sturgeon Bay and Shawanaga Inlet, Georgian Bay, Ontario

1972 ◽  
Vol 29 (1) ◽  
pp. 79-83 ◽  
Author(s):  
John C. H. Carter
Keyword(s):  
Late Summer ◽  
Planktivorous Fish ◽  
Seasonal Fluctuations ◽  
Bosmina Longirostris ◽  
Georgian Bay ◽  
Maximum Abundance ◽  
Planktonic Crustaceans ◽  
Limnocalanus Macrurus

Distribution and abundance of 27 planktonic crustaceans in an inshore area of Georgian Bay characterized by horizontal differences in temperature and electrolyte concentrations are described on the basis of duplicate vertical hauls on eight dates at six stations during ice-free months of 1970 and on one date at four stations through the ice in 1971. Most species were found at all stations on at least some occasions in 1970, although some differences in periods of maximum abundance between stations, probably related to temperature, were noted. Daphnia ambigua and Diaptomus reighardi were confined to the inner stations. Limnocalanus macrurus and Diaptomus sicilis were absent during periods of highest water temperatures. Eubosmina coregoni, although found throughout the system in February 1971, was restricted to the outer stations in 1970. A marked late-summer drop in populations of all species except Bosmina longirostris and Tropocyclops prasinus mexicanus in 1970 might have been due to either normal seasonal fluctuations or heavy predation by planktivorous fish.

scholarly journals SEASONAL DYNAMICS OF CICADAS (HEMIPTERA: CICADINA) ON THE TERRITORY OF THE TIGIREKSKY NATURE RESERVE (ALTAI KRAI)

2020 ◽  
Author(s):  
E.Yu. Mayorova ◽  
Keyword(s):  
Seasonal Dynamics ◽  
Nature Reserve ◽  
Late Summer ◽  
Maximum Abundance

The seasonal dynamics of cicadas (Hemiptera: Cicadina) has been investigated at five model locations of Tigireksky Nature Reserve (Altai Krai). 65 cicada species of 43 genera and 5 families have been identified. Two association clusters have been built: aestival and late-summer/autumnal. The maximum abundance for the families Cicadellidae and Membracidae was observed during latesummer/ autumnal period (early September and late July, respectively).

Spatial patterns and seasonal fluctuations of intertidal macroalgal assemblages from Tarifa Island, southern Spain: relationship with associated Crustacea

2010 ◽  
Vol 91 (1) ◽  
pp. 107-116 ◽  
Author(s):  
José M. Guerra-García ◽  
M. Pilar Cabezas ◽  
Elena Baeza-Rojano ◽  
J. Carlos García-Gómez
Keyword(s):  
Protected Area ◽  
Algal Species ◽  
Late Summer ◽  
Weather Conditions ◽  
Ulva Rigida ◽  
Seasonal Fluctuations ◽  
Strait Of Gibraltar ◽  
Valonia Utricularis ◽  
Fucus Spiralis ◽  
Chaetomorpha Aerea

The dominant intertidal algal species from Tarifa Island, Strait of Gibraltar, together with the associated peracarid crustacean community, were studied over a two-year period (December 2005–December 2007). Gelidium corneum and Gymnogongrus patens were dominant at the lower levels, close to the subtidal. Valonia utricularis, Osmundea pinnatifida, a turf of Caulacanthus ustulatus and Gelidium spp., Corallina elongata and Jania rubens were distributed in intermediate levels, while Ulva rigida, Chaetomorpha aerea and Fucus spiralis were collected from upper levels. The main intertidal seaweeds of Tarifa Island showed a perennial behaviour, but maximum values of biomass were registered during late spring and beginning of summer for most of species while the highest seawater temperatures were measured in late summer and beginning of autumn. Corallina elongata and Jania rubens, the dominant species which shared a niche at platforms of intermediate levels, showed an opposite behaviour, probably to avoid competence: C. elongata showed higher biomass in April–June and lower values in August–October–December, while biomass of J. rubens was higher in December–February and lower in April–August. Associated crustaceans, including mainly amphipods (gammarids and caprellids) were also present throughout the whole year with similar seasonality to seaweeds. However, crustacean density in the intertidal was not only influenced by distribution of algae as substrate, but also by external factors, such as hydrodynamism, oxygen, weather conditions, competition or predation. The present study constitutes the first baseline study dealing with seasonal fluctuations of algae and associated crustaceans in a protected area of the Strait of Gibraltar, an important biogeographical zone between Europe and Africa and the Mediterranean and Atlantic.

Population Dynamics of Limnetic Cladocera in a Beaver Pond

1975 ◽  
Vol 32 (3) ◽  
pp. 341-346 ◽  
Author(s):  
Judith K. Kwik ◽  
John C. H. Carter
Keyword(s):  
Population Dynamics ◽  
Embryonic Development ◽  
Carrying Capacity ◽  
Sampling Errors ◽  
Beaver Pond ◽  
Bosmina Longirostris ◽  
Georgian Bay ◽  
Development Times ◽  
Different Temperatures ◽  
Ceriodaphnia Quadrangula

In a small, shallow, predation free beaver pond near Georgian Bay, Ontario Ceriodaphnia quadrangula was monacmic and Daphnia ambigua and Bosmina longirostris triacmic. Each species peaked and declined rapidly, presumably overshooting the carrying capacity of a food limited environment. Embryonic development times of each species at different temperatures was determined in the laboratory and fitted with Bĕlahrádek’s function. Calculated instantaneous rates of birth and death were normal for D. ambigua and C. quadrangula but too low to account for the rapid fluctuations in numbers of B. longirostris, suggesting occasional gross sampling errors. Bosmina longirostris may periodically abandon the limnoplankton for a benthic existence thus avoiding capture.

Lucerne survival in relation to grass management on a brigalow land in south-east Queensland

1979 ◽  
Vol 19 (97) ◽  
pp. 198 ◽  
Author(s):  
GJ Leach ◽  
D Ratcliff
Keyword(s):  
Clay Soil ◽  
Relative Size ◽  
Late Summer ◽  
Seasonal Fluctuations ◽  
Active Growth ◽  
Original Population ◽  
Tropical Environments ◽  
Mean Size ◽  
Grass Growth ◽  
Drought Effects

Lucerne, Medicago sativa cv. Hunter River, was planted on a 90 cm x 90 cm grid on a fertile brigalow clay soil in south-east Queensland in November 1971. The lucerne was either cut regularly or cut annually. Volunteer species, principally grasses, were either mown regularly, 2-3 times as often as the lucerne during periods of active growth, or were also cut annually in late summer. Changes in lucerne vigour and survival were recorded about four times a year through to 1977. A few lucerne plants died between most samplings in each treatment. More substantial losses due to individual treatments were superimposed on the continuing small losses in successive summers. The first two summers following establishment were wetter than average, and as many as 41% of the original population died when volunteer species were cut annually. Where volunteer species were mown regularly from between lucerne plants, survival was good until the very dry 1974-75 summer when 35% of the original plants died. Our results thus suggest that lucerne plants were lost through their incompatibility with vigorous tropical grass growth, through drought effects, and also through the continuous slow erosion of the population : they emphasise the importance of managing vigorous grass growth if lucerne survival is to be prolonged in fertile sub-tropical environments. Vigour declined markedly only where4wzerne was regularly cut from within the annually cut volunteer species, but there were large seasonal fluctuations. The relative size of plants decreased over some 4 to 9 months before death, although there was an indication that those dying in summer were more representative of the population mean size. This suggests that summer deaths rapidly follow the occurrence of predisposing factors. In summer, management should aim mainly to prevent plant deaths, whereas at other times there may be additional scope for alleviating losses in productivity.

Life Cycles of Limnocalanus macrurus and Senecella calanoides, and Seasonal Abundance and Vertical Distributions of Various Planktonic Copepods, in Parry Sound, Georgian Bay

1969 ◽  
Vol 26 (10) ◽  
pp. 2543-2560 ◽  
Author(s):  
John C. H. Carter
Keyword(s):  
Thermal Stratification ◽  
Calanoid Copepod ◽  
Life Cycles ◽  
Seasonal Abundance ◽  
Cyclopoid Copepod ◽  
Georgian Bay ◽  
Vertical Distributions ◽  
Planktonic Copepods ◽  
Limnocalanus Macrurus ◽  
Mesocyclops Edax

The life cycles and vertical distributions of Limnocalanus macrurus and Senecella calanoides and the seasonal abundance and vertical distributions of adults of other planktonic copepods in Parry Sound, Georgian Bay, were determined from diurnal vertical plankton hauls taken on 14 occasions from June 19, 1967, through November 11, 1968. The most abundant cyclopoid copepod on most occasions was Cyclops bicuspidatus thomasi. Tropocyclops prasinus was common, particularly in summer and autumn. Mesocyclops edax and Cyclops vernalis were scarce. Cyclops bicuspidatus thomasi and T. prasinus were usually concentrated in the upper strata, T. prasinus seldom being deeper than 3 m during summer.The most abundant calanoid copepod was Diaptomus ashlandi. Diaptomus minutus and D. oregonensis were also common, but D. sicilis was rare. Diaptomus ashlandi and D. oregonensis occupied much the same depths in the metalimnion during the periods of thermal stratification but were deeper in spring and fall. Diaptomus minutus was concentrated mainly in the epilimnion even when thermal stratification was slight. Epischura lacustris and Eurytemora affinis were scarce. Limnocalanus macrurus was abundant and monocyclic, becoming adult in late spring but not spawning until autumn; older copepodites inhabited somewhat deeper strata than younger stages. Senecella calanoides was less abundant than L. macrurus but was also monocyclic, becoming adult in autumn and spawning almost immediately; all instars were usually found in deeper water than L. macrurus. The possibility that S. calanoides, because of its longer period of development, is better adapted to life in Parry Sound than L. macrurus is discussed.

Detection of Indigenous Enteric Viruses in Raw Sewage Effluents of the City of Athens, Greece, During a Two Year Survey

1985 ◽  
Vol 17 (10) ◽  
pp. 159-164 ◽  
Author(s):  
V. Krikelis ◽  
P. Markoulatos ◽  
N. Spyrou ◽  
Ch Serie
Keyword(s):  
Enteric Viruses ◽  
Late Summer ◽  
Early Spring ◽  
Seasonal Fluctuations ◽  
Urban Sewage ◽  
Sewage Effluents ◽  
Concentration Step ◽  
Early Fall ◽  
The City ◽  
Coxsackie B

In a two year survey of enteric viruses in urban sewage effluents of Athens, Greece, during 1982–1983, indigenous Enteroviruses and Adenoviruses have been detected. Enteroviruses, (Polio, Coxsackie B and Echo) were recovered on Vero or BGM cells by inoculation of samples, after a pre-concentration step utilizing glass powder. Adenoviruses were recovered on Hep2 cells after being Precipitated with protamine sulfate. The viral content was in the order of 102 -103 cytopathogenic units (CPU) per litre of sample. Seasonal fluctuations of the various serotypes recovered were observed. The peak of Adenoviruses was found in early spring whereas Enteroviruses peaked in late summer-early fall. The most frequently recovered serotypes within each group were : Polio III (47%), Coxsackie B5 (56%), Echo 7 (61%) and Adeno 7 (43%). Similar isolation frequencies, except for Polio, were found in humans as well. As regards Polioviruses, all strains recovered from sewage were found to be vaccine-related by the intratypic serodifferentiation test.

Seasonal population changes in Rhabdias ranae Walton, 1929 (Nematoda: Rhabdiasidae) in Rana sylvatica of Ontario

1979 ◽  
Vol 57 (1) ◽  
pp. 179-183 ◽  
Author(s):  
M. R. Baker
Keyword(s):  
Late Summer ◽  
Rana Sylvatica ◽  
Body Cavity ◽  
The Body ◽  
Population Changes ◽  
Seasonal Fluctuations ◽  
Two Generations ◽  
Early Fall ◽  
Young Of The Year ◽  
Seasonal Population

Rana sylvatica collected monthly from April to October of 1976 and 1977 in a marsh near Guelph, Ontario, were examined for the presence of Rhabdias ranae. Prevalence and intensity of infections were lowest in summer and highest in spring and early fall of both years. Many nematodes collected in late summer and early fall were subadults found in the body cavity of frogs and, therefore, this period was important for transmission. No nematodes were recovered from the body cavity of frogs in spring and few were recovered from this location in late fall. Seasonal fluctuations in size of worms indicates there was a single annual cycle of growth of worms and that there was only one or possibly two generations in frogs each year. The data indicate transmission began later in the spring of 1976 than 1977 and ceased later in the fall of 1976 than 1977. Young-of-the-year frogs acquired infections in the same summer they transformed from tadpoles. Survival of the species in Ontario is dependent on adult nematodes overwintering in frogs.

Ecological studies on the epipelic algal community in five prairie–parkland lakes in central Alberta

1978 ◽  
Vol 56 (8) ◽  
pp. 991-1009 ◽  
Author(s):  
Michael Hickman
Keyword(s):  
Standing Crop ◽  
Biotic Interactions ◽  
Late Summer ◽  
Nutrient Status ◽  
Algal Community ◽  
Seasonal Fluctuations ◽  
Physical Disturbance ◽  
Overlying Water ◽  
Light Levels ◽  
The Mean

Seasonal fluctuations of the epipelon in five eutrophic, prairie–parkland lakes were characterized by spring and late summer – autumn maxima, although midsummer peaks, dominated by chlorococcalean algae, occurred at the shallow stations in three lakes. Winter peaks were invariably dominated by algae of planktonic origin. The epipelon was light limited at the deep stations under ice cover during the winter. More correspondence than in previous studies was found between the standing crop and the nutrient status of the overlying water but no one single factor could account for seasonal fluctuations of the epipelon. Instead, a combination of light levels, nutrients, temperature, physical disturbance, and biotic interactions affected these fluctuations. The mean standing crop size of the epipelon was closely related to the mean bicarbonate levels.

Responses of Lake Pyhäjärvi (southwestern Finland) to variable recruitment of the major planktivorous fish, vendace (Coregonus albula)

1997 ◽  
Vol 54 (1) ◽  
pp. 32-40 ◽  
Author(s):  
H Helminen ◽  
J Sarvala
Keyword(s):  
Water Quality ◽  
Chlorophyll A ◽  
Late Summer ◽  
Planktivorous Fish ◽  
Total Biomass ◽  
Coregonus Albula ◽  
Functional Relationships ◽  
P Concentration ◽  
Class Strength ◽  
Lake Pyhäjärvi

We studied the functional relationships between water quality, phytoplankton, zooplankton, and planktivorous fish (vendace, Coregonus albula) in Lake Pyhäjärvi (southwestern Finland) in 1979-1992. The observed average values of water quality were typical of a mesoeutrophic system: total phosphorus (P) concentration, 16 mg · m-3; chlorophyll a, 5 mg · m-3; and Secchi depth, 3.3 m. The average total biomass of crustacean zooplankton in August was 62 mg carbon (C) · m-3, and large Daphnia spp. (>1.2 mm) were totally missing. The correlation between the late summer (August-September) chlorophyll a concentration and the total P concentration in the lake water was weak. The year-class strength of the vendace in autumn correlated significantly with late summer values of chlorophyll a. The August mean zooplankton biomass was negatively correlated both with the year-class strength of the vendace in autumn and with the August-September values of chlorophyll a, indicating the role of zooplankton as an intermediary in the trophic cascade of vendace feeding through the food web. We suggest that the reduced grazing pressure by zooplankton enabled the observed increase in phytoplankton biomass in years with a strong vendace stock.

Fluctuations in the inorganic constituents of inner bark of loblolly pine with season and soil series

1972 ◽  
Vol 50 (6) ◽  
pp. 1287-1293 ◽  
Author(s):  
Jerry D. White ◽  
L. T. Alexander ◽  
E. W. Clark
Keyword(s):  
Loblolly Pine ◽  
Late Summer ◽  
Soil Types ◽  
Soil Series ◽  
Seasonal Fluctuations ◽  
Inner Bark ◽  
Stable Period ◽  
Loblolly Pines ◽  
Inorganic Constituents

The concentrations of K, Ca, N, Mg, P, Al, Mn, Na, Zn, Fe, Cu, ash, and H2O in the inner bark of mature loblolly pines growing on three soil series were determined over a 1-year period. Concentrations of ash, H2O, Ca, Al, Mn, and Fe differed significantly among the trees on the three soil types. Most elements reached maximum concentrations in the fall and minimum concentrations in the spring. Ash, H2O, Mg, Mn, Zn, and Fe showed significant seasonal fluctuations. Because spring is a period of rapid transitions, late summer seems the most stable period in which to sample tissues from inner bark.

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