The effect of temperature on development and reproduction in Chorda filum and C. tomentosa (Phaeophyta, Laminariales) from Nova Scotia

1986 ◽  
Vol 64 (11) ◽  
pp. 2414-2420 ◽  
Author(s):  
I. Novaczek ◽  
C. J. Bird ◽  
J. McLachlan
Keyword(s):  
Nova Scotia ◽  
Water Temperature ◽  
Temperature Regime ◽  
Water Surface ◽  
Atlantic Coast ◽  
Effect Of Temperature ◽  
Late Winter ◽  
Field Temperature ◽  
Dim Light ◽  
Young Sporophytes

The occurrence of sporophytes of Chorda tomentosa and C. filum in the southern Gulf of St. Lawrence was correlated with the field temperature regime. Temperature tolerances of gametophytes and young sporophytes of both species were tested in culture, using isolates from both the gulf and the outer Atlantic coast of Nova Scotia. Chorda tomentosa sporophytes appeared in late winter when the water surface was frozen, were fertile from April to June, and died when water temperature approached 20 °C. In culture, sporophytes tolerated −1 to 15 but became moribund at 20 °C. Gametophytes in constant temperature reproduced readily at 5 °C, occasionally at 0 and 10 °C, but not at higher temperatures; they survived to 24 °C. After 6 months in dim light at 10 °C some gametophytes also released gametes at 15 °C. Sporophytes of C. filum appeared in the field in spring after the water temperature had risen above 1 °C and persisted through the warm months. New sporophytes appeared in the autumn after the water temperature dropped below 15 °C but did not survive the winter. In culture, sporophytes died at −1 and 28 °C and survived between 0 and 24 °C. Gametophytes reproduced readily from 5 to 12, rarely at 0 and 15 °C, and not at higher temperatures. Gametophytes of both species survived 5 months in 0 ± 2 °C, [Formula: see text].

Life History, Ecological Production, and an Empirical Mathematical Model of the Population of Sagitta elegans in St. Margaret's Bay, Nova Scotia

1971 ◽  
Vol 28 (7) ◽  
pp. 971-985 ◽  
Author(s):  
D. D. Sameoto
Keyword(s):  
Mathematical Model ◽  
Life History ◽  
Nova Scotia ◽  
Reproductive Potential ◽  
The Body ◽  
Effect Of Temperature ◽  
Late Winter ◽  
Turnover Rates ◽  
Flushing Rate ◽  
Effects Of Temperature

The population of Sagitta elegans Verrill in St. Margaret's Bay, Nova Scotia, was polymodal throughout the year. The modes were distinct enough to be considered as representing subpopulations. Four subpopulations were present in the Bay during the early winter and a fifth subpopulation entered the Bay during the late winter. The growth of the subpopulations was followed through the year and related to the mean water temperature. A mathematical model describing the effect of temperature on development, length of the life cycle, and reproductive potential is presented. The model simulates the effects of temperature on the body length at maturation, ovary length, generation time, and numbers surviving at various body lengths. Predictions are made on the changes in population size due to temperature, and mortality and flushing rate changes. The calorific content of the animals at different stages of the life history are given along with the carbon content of the animals. A yearly ecological production figure is given based on the turnover rates derived from the Allen curve for one of the subpopulations. The significance of the findings is discussed in relation to the geographic distribution of the species.

scholarly journals Ecological determinants of intertidal recruitment and metacommunity structure on the Atlantic coast of Nova Scotia

2018 ◽  
Author(s):  
Ricardo A. Scrosati ◽  
Julius A. Ellrich
Keyword(s):  
Nova Scotia ◽  
Atlantic Coast ◽  
Seawater Temperature ◽  
Rocky Intertidal ◽  
Late Winter ◽  
In Situ Data ◽  
Sessile Invertebrates ◽  
Filter Feeders ◽  
Metacommunity Structure ◽  
Rocky Habitats

Rocky-intertidal species are often distributed as metacommunities along marine shores, as rocky habitats are patchy. Nearshore pelagic conditions often explain variation among the local communities, but most studies have been done on eastern ocean boundary coasts. We investigated potential drivers of intertidal metacommunity structure on the Atlantic coast of Nova Scotia. We studied the high intertidal zone of nine wave-exposed bedrock locations spanning 425 km of coastline. At each location in the spring, we measured the recruitment of barnacles and mussels, the two predominant sessile invertebrates. Satellite data on coastal phytoplankton abundance and particulate organic carbon (food supply for intertidal filter-feeders) and in-situ data on coastal seawater temperature explained to varying degrees the geographic structure of recruitment. In turn, the summer abundance of both filter-feeders was positively related to their spring recruitment. Ultimately, predator (dogwhelk) abundance increased with the recruitment and abundance of barnacles and mussels (the main prey of dogwhelks), suggesting that bottom-up forcing influences metacommunity structure on this coast. Sea ice constituted an overlapping source of variation. Drift ice leaving the Gulf of St. Lawrence in late winter disturbed intertidal communities in the northern locations, limiting local biodiversity compared with central and southern locations.

scholarly journals Ecological determinants of intertidal recruitment and metacommunity structure on the Atlantic coast of Nova Scotia

2018 ◽  
Author(s):  
Ricardo A. Scrosati ◽  
Julius A. Ellrich
Keyword(s):  
Nova Scotia ◽  
Atlantic Coast ◽  
Seawater Temperature ◽  
Rocky Intertidal ◽  
Late Winter ◽  
In Situ Data ◽  
Sessile Invertebrates ◽  
Filter Feeders ◽  
Metacommunity Structure ◽  
Rocky Habitats

Rocky-intertidal species are often distributed as metacommunities along marine shores, as rocky habitats are patchy. Nearshore pelagic conditions often explain variation among the local communities, but most studies have been done on eastern ocean boundary coasts. We investigated potential drivers of intertidal metacommunity structure on the Atlantic coast of Nova Scotia. We studied the high intertidal zone of nine wave-exposed bedrock locations spanning 425 km of coastline. At each location in the spring, we measured the recruitment of barnacles and mussels, the two predominant sessile invertebrates. Satellite data on coastal phytoplankton abundance and particulate organic carbon (food supply for intertidal filter-feeders) and in-situ data on coastal seawater temperature explained to varying degrees the geographic structure of recruitment. In turn, the summer abundance of both filter-feeders was positively related to their spring recruitment. Ultimately, predator (dogwhelk) abundance increased with the recruitment and abundance of barnacles and mussels (the main prey of dogwhelks), suggesting that bottom-up forcing influences metacommunity structure on this coast. Sea ice constituted an overlapping source of variation. Drift ice leaving the Gulf of St. Lawrence in late winter disturbed intertidal communities in the northern locations, limiting local biodiversity compared with central and southern locations.

scholarly journals Ecological determinants of intertidal recruitment and metacommunity structure on the Atlantic coast of Nova Scotia

2018 ◽  
Author(s):  
Ricardo A. Scrosati ◽  
Julius A. Ellrich
Keyword(s):  
Nova Scotia ◽  
Atlantic Coast ◽  
Seawater Temperature ◽  
Rocky Intertidal ◽  
Late Winter ◽  
In Situ Data ◽  
Sessile Invertebrates ◽  
Filter Feeders ◽  
Metacommunity Structure ◽  
Rocky Habitats

Rocky-intertidal species are often distributed as metacommunities along marine shores, as rocky habitats are patchy. Nearshore pelagic conditions often explain variation among the local communities, but most studies have been done on eastern ocean boundary coasts. We investigated potential drivers of intertidal metacommunity structure on the Atlantic coast of Nova Scotia. We studied the high intertidal zone of nine wave-exposed bedrock locations spanning 415 km of coastline. At each location in the spring, we measured the recruitment of barnacles and mussels, the two predominant sessile invertebrates. Satellite data on coastal phytoplankton abundance and particulate organic carbon (food supply for intertidal filter-feeders) and in-situ data on coastal seawater temperature explained to varying degrees the geographic structure of recruitment. In turn, the summer abundance of both filter-feeders was positively related to their spring recruitment. Ultimately, predator (dogwhelk) abundance increased with the recruitment and abundance of barnacles and mussels (the main prey of dogwhelks), suggesting that bottom-up forcing influences metacommunity structure on this coast. Sea ice constituted an overlapping source of variation. Drift ice leaving the Gulf of St. Lawrence in late winter disturbed intertidal communities in the northern locations, limiting local biodiversity compared with central and southern locations.

scholarly journals Ecological determinants of intertidal recruitment and metacommunity structure on the Atlantic coast of Nova Scotia

2018 ◽  
Author(s):  
Ricardo A. Scrosati ◽  
Julius A. Ellrich
Keyword(s):  
Nova Scotia ◽  
Atlantic Coast ◽  
Seawater Temperature ◽  
Rocky Intertidal ◽  
Late Winter ◽  
In Situ Data ◽  
Sessile Invertebrates ◽  
Filter Feeders ◽  
Metacommunity Structure ◽  
Rocky Habitats

Rocky-intertidal species are often distributed as metacommunities along marine shores, as rocky habitats are patchy. Nearshore pelagic conditions often explain variation among the local communities, but most studies have been done on eastern ocean boundary coasts. We investigated potential drivers of intertidal metacommunity structure on the Atlantic coast of Nova Scotia. We studied the high intertidal zone of nine wave-exposed bedrock locations spanning 415 km of coastline. At each location in the spring, we measured the recruitment of barnacles and mussels, the two predominant sessile invertebrates. Satellite data on coastal phytoplankton abundance and particulate organic carbon (food supply for intertidal filter-feeders) and in-situ data on coastal seawater temperature explained to varying degrees the geographic structure of recruitment. In turn, the summer abundance of both filter-feeders was positively related to their spring recruitment. Ultimately, predator (dogwhelk) abundance increased with the recruitment and abundance of barnacles and mussels (the main prey of dogwhelks), suggesting that bottom-up forcing influences metacommunity structure on this coast. Sea ice constituted an overlapping source of variation. Drift ice leaving the Gulf of St. Lawrence in late winter disturbed intertidal communities in the northern locations, limiting local biodiversity compared with central and southern locations.

Effect of temperature on streambed vertical hydraulic conductivity

2013 ◽  
Vol 45 (1) ◽  
pp. 89-98 ◽  
Author(s):  
Weihong Dong ◽  
Gengxin Ou ◽  
Xunhong Chen ◽  
Zhaowei Wang
Keyword(s):  
Hydraulic Conductivity ◽  
Water Temperature ◽  
Sediment Cores ◽  
Effect Of Temperature ◽  
In Situ Tests ◽  
Effect Of Water ◽  
Vertical Hydraulic Conductivity ◽  
Increasing Trend ◽  
Streambed Vertical Hydraulic Conductivity

In this study, in situ and on-site permeameter tests were conducted in Clear Creek, Nebraska, USA to evaluate the effect of water temperature on streambed vertical hydraulic conductivity Kv. Fifty-two sediment cores were tested. Five of them were transferred to the laboratory for a series of experiments to evaluate the effect of water temperature on Kv. Compared with in situ tests, 42 out of the 52 tests have higher Kv values for on-site tests. The distribution of water temperature at the approximately 50 cm depth of streambed along the sand bar was investigated in the field. These temperatures had values in the range 14–19 °C with an average of 16 °C and had an increasing trend along the stream flow. On average, Kv values of the streambed sediments in the laboratory tests increase by 1.8% per 1 °C increase in water temperature. The coarser sandy sediments show a greater increase extent of the Kv value per 1 °C increase in water temperature. However, there is no distinct increasing trend of Kv value for sediment containing silt and clay layers.

scholarly journals Life histories and distribution of ostracods with depth in western Lake Geneva (Petit-Lac), Switzerland: a reconnaissance study

Crustaceana ◽  
2014 ◽  
Vol 87 (8-9) ◽  
pp. 1095-1123 ◽  
Author(s):  
Laurent Decrouy ◽  
Torsten W. Vennemann
Keyword(s):  
Life History ◽  
Water Temperature ◽  
Water Depth ◽  
Organic Matter Content ◽  
Environmental Parameters ◽  
Late Winter ◽  
Lake Geneva ◽  
Monthly Basis ◽  
Sampling Campaign ◽  
Western Lake

Because environmental conditions within a given basin are different for each season and at different water depth, knowledge of the life history and depth distribution of target species is important for environmental and palaeoenvironmental interpretations based on ostracod species assemblages and/or the geochemical compositions of their valves. In order to determine the distribution of species with depth as well as the life history of species from Lake Geneva, a one-year sampling campaign of living ostracods was conducted at five sites (2, 5, 13, 33 and 70 m water depth) on a monthly basis in the Petit-Lac (western basin of Lake Geneva, Switzerland). Based on the results, the different species can be classified into three groups. Littoral taxa are found at 2 and 5 m water depth and include, in decreasing numbers of individuals,Cypridopsis vidua(O. F. Müller, 1776),Pseudocandona compressa(Koch, 1838),Limnocythere inopinata(Baird, 1843),Herpetocypris reptans(Baird, 1835),Potamocypris smaragdina(Vávra, 1891),Potamocypris similis(G. W. Müller, 1912),Plesiocypridopsis newtoni(Brady & Robertson, 1870),Prionocypris zenkeri(Chyzer & Toth, 1858) andIlyocyprissp. Brady & Norman, 1889. Sublittoral species are found in a majority at 13 m water depth and to a lesser extend at 33 m water depth and include, in decreasing numbers of individuals,Fabaeformiscandona caudata(Kaufmann, 1900),Limnocytherina sanctipatricii,Candona candida(O. F. Müller, 1776) andIsocypris beauchampi(Paris, 1920). Profundal species are found equally at 13, 33 and 70 m water depth and includes, in decreasing numbers of individuals,Cytherissa lacustris(Sars, 1863),Candona neglectaSars, 1887 andCypria lacustrisLilljeborg, 1890. The occurrence ofLimnocytherina sanctipatricii(Brady & Robertson, 1869) is restricted from late winter to late spring when temperatures are low, whileC. vidua,L. inopinata,P. smaragdina,P. similis,P. newtoniandIlyocyprissp. occur predominantly from spring to early autumn when temperatures are high. Individuals ofC. neglecta,C. candida,F. caudata,P. compressa,C. lacustris,H. reptansandCp. lacustrisoccur throughout the year with juveniles and adults occurring during the same period (C. neglectaat 70 m,C. lacustrisat 13, 33 and 70 m, andH. reptansat 2, 5 and 13 m water depth) or with juveniles occurring during a different period of the year than adults (C. neglectaat 13 and 33 m andC. candida,F. caudataandP. compressaat their respective depth of occurrence). Among the environmental parameters investigated, an estimate of the relationship between ostracod autoecology and environmental parameters suggests that in the Petit-Lac: (i) water temperature and substrate characteristics are important factors controlling the distribution of species with depth, (ii) water temperature is also important for determining the timing of species development and, hence, its specific life history, and (iii) water oxygen and sedimentary organic matter content is less important compared to the other environmental parameter monitored.

scholarly journals Effect of water temperature and pH on the concentration and time of ozone saturation

2018 ◽  
Vol 21 (0) ◽  
Author(s):  
Melicia Cintia Galdeano ◽  
Allan Eduardo Wilhelm ◽  
Isabella Borges Goulart ◽  
Renata Valeriano Tonon ◽  
Otniel Freitas-Silva ◽  
...  
Keyword(s):  
Water Temperature ◽  
Molecular Oxygen ◽  
Half Life ◽  
Low Ph ◽  
Ozone Content ◽  
Effect Of Temperature ◽  
Saturation Time ◽  
Gas Concentration ◽  
Ph Values ◽  
Effect Of Water

Abstract Ozone has been used for many years to disinfect water due to its oxidizing potential. Since it decomposes quickly into molecular oxygen, leaving no residue, it has important advantages for use. The decomposition of ozone is affected by the temperature and pH of the medium, low pH values and temperatures increasing its half-life, which can result in more efficient disinfection. With the objective of increasing the effectiveness of ozonation, this study investigated the effect of temperature (8 ºC and 25 °C) and pH (3.0 and 6.0) of the water on the saturation time and gas concentration, employing two initial gas concentrations (13.3 and 22.3 mg L-1). The concentration of ozone saturation increased as the temperature and pH of the medium decreased, as also with the higher initial gas concentration ( C0). The highest saturation concentrations were obtained at pH 3.0 and 8 °C (4.50 and 8.03 mg L-1 with C0 of 13.3 and 22.3 mg L-1, respectively). This higher ozone content could result in greater decontamination efficiency of the food products washed with this water.

scholarly journals Establishing patterns in the effect of temperature regime when manufacturing nanocomposites on their heat-conducting properties

2021 ◽  
Vol 4 (5(112)) ◽  
pp. 21-26
Author(s):  
Nataliia Fialko ◽  
Roman Dinzhos ◽  
Julii Sherenkovskii ◽  
Nataliia Meranova ◽  
Diana Izvorska ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Temperature Regime ◽  
Main Parameter ◽  
Polymer Melt ◽  
Effect Of Temperature ◽  
Heat Conducting ◽  
Composite Manufacturing ◽  
Energy Saving Technology ◽  
Percolation Thresholds ◽  
The Impact

This paper reports the experimental study carried out to establish the dependence of the thermal conductivity of polypropylene-based nanocomposites filled with carbon nanotubes on the main parameter of the temperature regime of their manufacturing ‒ the level of overheating a polymer melt relative to its melting point. The study has been conducted for nanocomposites that were manufactured by applying a method based on the mixing of components in the polymer melt applying a special disk extruder. During the composite manufacturing process, the level of melt overheating varied from 10 to 75 K, with the mass share of filler ranging from 0.3 to 10.0 %. It is shown that increasing the overheating of a polymer melt causes an increase in the thermal conductivity of the composites. However, when the overheating has reached a certain value, its further growth does not increase the thermal conductivity of nanocomposites. Based on the established pattern, the rational level of this overheating has been determined. That resolves the tasks of manufacturing highly heat-conducting nanocomposites and implementing appropriate energy-saving technology. Data have been acquired on the effects of the impact of the amount of polymer melt overheating on the values of the first and second percolation thresholds for the examined nanocomposites. It is established that the value of the first percolation threshold is more sensitive to the specified amount of overheating. The dependences of the density of the examined composites on the level of polymer melt overheating have been derived. The correlation between a given dependence and the nature of a corresponding change in the thermal conductivity of the composites has been established. Applying the proposed highly heat-conducting nanocomposites is promising for micro and nanoelectronics, energy, etc.

scholarly journals Influence of beech forests fragmentation of Stilsky Hillside on their microclimatic parameters

2020 ◽  
pp. 81-88
Author(s):  
Oleg Оrlov ◽  
Maryna Ragulina
Keyword(s):  
Water Temperature ◽  
Edge Effect ◽  
Temperature Regime ◽  
Biodiversity Loss ◽  
Beech Forests ◽  
Small Areas ◽  
Regime Changes ◽  
Interior Forest ◽  
Floristic Structure ◽  
Sensitive Marker

Estimation of changes in the microclimatic parameters of beech forests of the Stilsky Hillside, by measuring the water-temperature indicators of the soil regime and bryoindication, were performed. Fragmentation of forest causes significant changes in microclimatic parameters in bondary habitats areas, which leads to both biodiversity loss and a decrease of the unchanged forest areas. In fragmented beech forests, the influence of the edge effect on the water-temperature regime of soils is observed within a distance of 20-40 meters, but the eco-floristic structure of nemoral moss vegetation is stabilized only at a distance from 160 m. Thus, bryobiontes are a shown to be a sensitive marker of the microclimatic regime changes in a fragmented ecosystem. In the studied beeches Metzgeria furcata, Radula complanata, Anomodon attenuatus, A. viticulosus, Cirriphyllum crassinervium are indicators of the "interior forest". The determined amplitude of the edge effect indicates the fragmentation as a crucial factor on the small areas of forest and its role in the loss of climate-sensitive groups of biota, primarily mosses.

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