THE DIURNAL ACTIVITY OF THE LARGER INVERTEBRATES AT THE SURFACE OF LAC LA RONGE, SASKATCHEWAN

1959 ◽  
Vol 37 (6) ◽  
pp. 945-956 ◽  
Author(s):  
J. H. Mundie
Keyword(s):  
Hyalella Azteca ◽  
Diurnal Activity ◽  
Large Lake ◽  
Mysis Relicta ◽  
Chironomid Larvae ◽  
The Hours ◽  
Chironomid Midges ◽  
Different Depths ◽  
Benthic Animals

Horizontal hauls were made with a pair of large plankton nets at the surface of a large lake to determine the 24-hour emergence cycle of chironomid midges rising from different depths and to investigate the occurrence of the larger invertebrates at the surface. Chironomid pupae ascend mainly in the hours of darkness and emergence may be immediate, as in Psilotanypus rufovittatus, or delayed for several hours, as in Procladius choreus. A migration to the surface at night is demonstrated for Mysis relicta and the amphipods Pontoporeia affinis and Hyalella azteca. Chironomid larvae and a variety of other invertebrates also occur at the surface. The findings show that many benthic animals are less static in their distribution than is commonly accepted.

Accumulation of Mercury by Plankton and Benthic Invertebrates in Riverine Lakes of Northern Manitoba (Canada): Importance of Regionally and Seasonally Varying Environmental Factors

1988 ◽  
Vol 45 (10) ◽  
pp. 1744-1757 ◽  
Author(s):  
Togwell A. Jackson
Keyword(s):  
Organic Matter ◽  
Environmental Factors ◽  
Benthic Invertebrates ◽  
Spring Flood ◽  
Chironomid Larvae ◽  
Decomposition Of Organic Matter ◽  
Preferential Uptake ◽  
Predominant Effect ◽  
Benthic Animals ◽  
Hg Accumulation

Mercury (Hg) concentrations in plankton and benthic invertebrates from riverine lakes of northern Manitoba were generally found to be unrelated, or inversely related, to inorganic and methyl mercury levels and Hg methylation rates in their habitats but were strongly dependent on environmental factors. The relationships suggest that the uptake of Hg by these organisms was controlled largely by suspended and sedimentary Hg-binding substances such as FeOOH, MnOOH, organic matter, sulfides, and clay. The sole exception was midsummer phytoplankton, whose Hg content was a function of Hg levels in local sediments, probably because interference by suspended detritus was minimal; during the spring flood, such interference had a predominant effect. Aeration of lake water by fluvial currents probably enhances the availability of Hg to plankton by promoting decomposition of organic matter and sulfides but decreases the availability of Hg to some benthic animals by causing MnOOH precipitation. FeOOH apparently limits Hg uptake by chironomid larvae but MnOOH limits Hg uptake by oligochaetes, nematodes, and pelecypods, suggesting preferential uptake of certain forms of Hg by particular biological and mineral species. Decreases in temperature may also retard Hg uptake by benthos. Biodilution has no significant effect on Hg accumulation by benthos or plankton.

scholarly journals Diurnal Variations in the Grazing of Planktonic Copepods

1953 ◽  
Vol 31 (3) ◽  
pp. 461-474 ◽  
Author(s):  
D. T. Gauld
Keyword(s):  
Vertical Migration ◽  
Diurnal Variations ◽  
Calanus Finmarchicus ◽  
Feeding Rhythm ◽  
The Hours ◽  
Different Depths ◽  
Planktonic Copepods ◽  
Diurnal Vertical Migrations

Records were made of the presence or absence of food in the guts of Calanus finmarchicus caught in three different depths, at intervals of 4 hr. through 24 hr. It was found that 80-100 % of the Calanus caught at the surface were full of food at all hours of the day.The number of Calanus containing food in deeper water was distinctly less. This may be correlated with the abundance of its food close to the surface. Diurnal vertical migrations took place on some occasions when samples were taken, but not on all.In the absence of vertical migration Calanus was abundant at the surface and feeding continuously at all hours of the 24 hr. Where vertical migration took place feeding was mostly at the surface and was restricted to the hours of darkness, i.e. in summer to a period distinctly less than 8 hr. round midnight. Laboratory observations confirm the absence of any feeding rhythm.

Brand Marks on the Starfish,Asterina Pectinifera

1998 ◽  
Vol 78 (2) ◽  
pp. 677-680 ◽  
Author(s):  
Takeo Kurihara
Keyword(s):  
The Body ◽  
Diurnal Activity ◽  
Ecological Studies ◽  
Mark Recapture ◽  
Stichopus Japonicus ◽  
Movement Rates ◽  
Brand Marks ◽  
The Mean ◽  
Asterina Pectinifera ◽  
Benthic Animals

Various marking techniques have been used in ecological studies of starfish as well as other benthic animals (Nielsen, 1992). They include the attachment of tags (Feder, 1955), staining with dye (Hancock, 1958), inscription with sharp pencil (Scheibling, 1980), and branding (T.K, unpublished data). These methods have been used in mark-recapture surveys over durations of several days in order to study the diurnal activity rhythmn (Burla et al., 1972), movement after displacement (Pabst & Vicentini, 1978), and feeding and movement rates (Keesing & Lucas, 1992). However, these marking techniques on starfish have never been quantitatively evaluated for their durability and detrimental effects on the starfish.Accordingly, in the present study, brand marks onAsterina pectinifera(Müller & Troschel) were examined in the laboratory in terms of their durability and impact on mortality and growth. For Echinodermata, branding has been used mainly on Holothuroidea likeStichopus japonicus(Arakawa, 1990). However, it can also be used for starfish to identify individuals by marking patterns on the body (T.K., unpublished data). The present study tested the effects on the growth and mortality ofA. pectinifera. It also examined the durability of brands for distinguishing individuals of a branded group from individuals of an unbranded group, and the durability for identifying individuals with specific coded brand marks.Two hundred starfish were collected in Maizuru Bay (35°29′N 135°22′E) in September 1995, and the size was measured. The five arms of each individual were measured from the centre of the disc to the arm tip (mm) to determine the mean radius (R0).

Observations on the seaward migration of Atlantic salmon (Salmo salar L.) smolts through a large lake as determined by radiotelemetry and Carlin tagging studies

1988 ◽  
Vol 66 (3) ◽  
pp. 685-691 ◽  
Author(s):  
C. E. Bourgeois ◽  
M. F. O'Connell
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Swimming Speed ◽  
Large Lake ◽  
Atlantic Salmon Salmo Salar ◽  
Seaward Migration ◽  
The Hours

Seaward movements of Atlantic salmon (Salmo salar L.) smolts through Red Indian Lake were studied using radiotelemetry and Carlin tagging. Movements of smolts through the lake occurred between the hours of 20:00 and 04:30 as determined from radiotelemetry. Carlin tagging revealed a net swimming speed ranging from 1.8 to 15.6 km/day; radiotelemetry revealed a rate of <1.0 to 11.2 km/day. Smolt movement through Red Indian Lake and other large insular Newfoundland lakes might be achieved through active migration as opposed to passive displacement. This aspect is discussed in the context of insular Newfoundland stocks for which extensive use of lakes by juveniles for rearing has been demonstrated.

Seasonal Patterns in Lipid Content of Lake Michigan Macroinvertebrates

1985 ◽  
Vol 42 (11) ◽  
pp. 1827-1832 ◽  
Author(s):  
Wayne S. Gardner ◽  
Thomas F. Nalepa ◽  
William A. Frez ◽  
Elizabeth A. Cichocki ◽  
Peter F. Landrum
Keyword(s):  
Lipid Content ◽  
Seasonal Changes ◽  
Loss Rate ◽  
Lake Michigan ◽  
Dry Weight ◽  
Seasonal Patterns ◽  
Organic Detritus ◽  
Mysis Relicta ◽  
Chironomid Larvae

Lipids in several taxa of macroinvertebrates from Lake Michigan were determined seasonally to help define the role of these animals in transferring energy in the lake. Ranges of mean lipid content relative to ash-free dry weight (AFDW) throughout the year were as follows: amphipods (Pontoporeia hoyi), 21–54%; lumbriculid oligochaetes (Stylodrilus heringianus), 12–19%; tubificid oligochaetes, 9–22%; chironomid larvae, 9–39%; and Mysis relicta, 26–37%. A pattern of increasing lipid content during spring was observed for P. hoyi, chironomids, and M. relicta, but seasonal changes were not apparent for oligochaetes. Excluding M. relicta, P. hoyi accounted for about 65% of the biomass and 70% of the energy contained in southern Lake Michigan benthic macroinvertebrates and may assimilate up to 30% of the total bioavailable organic detritus settling into the offshore hypolimnion. Calculation of the predation loss rate (production rate minus nonpredatory death rate) of P. hoyi indicated that about 13 000 cal∙m−2 (2.1 g AFDW∙m−2) of this amphipod may be consumed annually by fish and other predators in southern Lake Michigan.

Drift of invertebrates in an intermittent stream draining marshy terrain of west-central Alberta

1972 ◽  
Vol 50 (7) ◽  
pp. 985-991 ◽  
Author(s):  
Hugh F. Clifford
Keyword(s):  
Pore Size ◽  
Detrimental Effect ◽  
Main Stream ◽  
Immature Stages ◽  
Intermittent Stream ◽  
Chironomid Larvae ◽  
West Central ◽  
Benthic Animals

Seven 24-h drift samples were taken with a plankton net (pore size: 76 μ) over a 1-year period from an intermittent stream that drains marshy, muskeg-type terrain of west-central Alberta, Canada. The drift was mainly composed of planktonic and benthic animals originating in the marsh. The only abundant lotic taxon in the drift was simuliid larvae. Rotifers and cyclopoid nauplii were numerically the most important taxa. Drift densities for the fauna as a whole tended to decrease as the ice-free season progressed, but there was no consistent correlation between drift densities and flow. However total daily drift across a point varied directly with flow. All the abundant taxa drifted more during the day than at night, and nematodes, harpacticoids, simuliid larvae, chironomid larvae, chydorids, and rotifers were found in significantly (P < 0.05) greater numbers in the daytime drift. Drift rates of taxa caught in the plankton net were compared with drift rates of the same taxa caught in a 320-μ drift net. Rotifers, entomostracans (especially the immature stages), and even small simuliid and chironomid larvae would have been seriously underestimated using only the 320-μ net. The marshy areas via drift through the intermittent tributaries contribute a very large number of small organisms to the main stream. Draining the wetlands might have a pronounced detrimental effect on the main stream's ecosystem.

scholarly journals Results of zoobentos research in river Sotka, PINEZHSKY STATE RESERVE (Arkhangelsk region, Russia)

2021 ◽  
pp. 16-30
Author(s):  
Сергей Николаевич Артемьев ◽  
Александр Павлович Новоселов ◽  
Николай Владимирович Климовский ◽  
Геннадий Александрович Дворянкин ◽  
Олег Станиславович Дурныкин
Keyword(s):  
Water Quality ◽  
Taxonomic Diversity ◽  
Bivalve Mollusks ◽  
Chironomid Larvae ◽  
Spatial Aspect ◽  
Species Similarity ◽  
Bristle Worms ◽  
Quantitative Indicators ◽  
Benthic Animals ◽  
Benthic Sampling

В статье рассмотрен качественный состав (видовое и таксономическое разнообразие) и количественные показатели (встречаемость, численность и биомасса) зообентоса р. Сотка в пространственном аспекте. Выявлены участки реки с минимальной и максимальной численностью и биомассой. Определены доминирующие группы донных животных по численности (личинки хирономид и малощетинковые черви) и биомассе (двукрылые, олигохеты и двустворчатые моллюски). На основе кластерного анализа (по видовому сходству) станции отбора бентосных проб объединены в 2 группы. Качество вод оценено как условно чистое - слабо загрязненное. Проведенные исследования зообентоса в уникальной реке на территории заповедника Пинежский будут использованы при ведении комплексного мониторинга качества вод и биотической части ее экосистемы (фито- и зоопланктон, зообентос, ихтиофауна), включая и приточную систему. The article considers the qualitative composition (species and taxonomic diversity) and quantitative indicators (occurrence, number and biomass) of zoobenthos of river Sotka in the spatial aspect. The sections of the river with the minimum and maximum abundance and biomass were identified. The dominant groups of benthic animals were determined by their numbers (chironomid larvae and small-bristle worms) and biomass (dipterans, oligochaetes and bivalve mollusks). Comparison of quantitative indicators in the annual aspect revealed a significant increase in biomass and relative stability of abundance over a 20-year period at the Filippovskoye site, as well as a decrease in numbers and biomass at the Moiseev Nos site. Based on cluster analysis (by species similarity), benthic sampling stations are combined into 2 groups. Water quality is assessed as conditionally pure, slightly polluted. Studies of zoobenthos in a unique river on the territory of the Pinezhsky reserve will be used to conduct a comprehensive monitoring of water quality and the biotic part of its ecosystem (phyto- and zooplankton, zoobenthos, ichthyofauna), including the inflow system.

scholarly journals Alternative Use of Artificial Quarry Lakes as a Source of Thermal Energy for Greenhouses

Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3560
Author(s):  
Jessica Maria Chicco ◽  
Felix-Antoine Comeau ◽  
Alessandro Casasso ◽  
Cesare Comina ◽  
Nicolò Giordano ◽  
...  
Keyword(s):  
Thermal Energy ◽  
Operating Costs ◽  
Heat Extraction ◽  
Mixing Process ◽  
Large Lake ◽  
Qualitative Comparison ◽  
Groundwater Systems ◽  
Different Depths ◽  
Nw Italy ◽  
Definition Of

In northern Italy, most greenhouses rely on gas or oil heaters which are sometimes subject to high operating costs. Several greenhouses are nearby quarry lakes, which are the legacy of the expansion of cities in the last decades, including Turin (NW Italy). About 20 quarry lakes were excavated close to the Po riverbed in the southern part of this urban area, along a belt of more than 30 km in length, with an overall volume exceeding 10 million m3 water. The study addresses these artificial lakes as a low enthalpy thermal energy source, potentially providing heat to surrounding agri-business buildings. Detailed temperature monitoring of a large lake quarry was conducted over two years at different depths, measuring the surrounding groundwater level as well. Two different behaviors of the lake during the winter and summer seasons enabled the definition of a quite low water mixing process between the surrounding aquifers and the lake (in the range of 2–4 °C). An evaluation of the heat extraction potential using the lake as a heat source, depending on water temperature and its volume, and a qualitative comparison with groundwater systems are proposed. This study contributes to increasing knowledge on an overlooked resource for sustainable heating.

Multiple-fracturing and viewing of the same frozen sample at different depths using a low temperature FESEM

1996 ◽  
Vol 54 ◽  
pp. 820-821
Author(s):  
M.V. Parthasarathy ◽  
C. Daugherty
Keyword(s):  
Temperature Field ◽  
Low Temperature ◽  
Field Emission ◽  
Multiple Fracture ◽  
Precise Control ◽  
Cold Stage ◽  
Different Depths ◽  
Transfer Device

The versatility of Low Temperature Field Emission SEM (LTFESEM) for viewing frozen-hydrated biological specimens, and the high resolutions that can be obtained with such instruments have been well documented. Studies done with LTFESEM have been usually limited to the viewing of small organisms, organs, cells, and organelles, or viewing such specimens after fracturing them.We use a Hitachi 4500 FESEM equipped with a recently developed BAL-TEC SCE 020 cryopreparation/transfer device for our LTFESEM studies. The SCE 020 is similar in design to the older SCU 020 except that instead of having a dedicated stage, the SCE 020 has a detachable cold stage that mounts on to the FESEM stage when needed. Since the SCE 020 has a precisely controlled lock manipulator for transferring the specimen table from the cryopreparation chamber to the cold stage in the FESEM, and also has a motor driven microtome for precise control of specimen fracture, we have explored the feasibility of using the LTFESEM for multiple-fracture studies of the same sample.

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