Water temperature regime of selected lakes on James Ross Island during 2015 austral summer

2017 ◽  
Vol 7 (1) ◽  
pp. 83-93 ◽  
Author(s):  
Jan Kavan
Keyword(s):  
Water Temperature ◽  
Temperature Regime ◽  
Shallow Lake ◽  
Austral Summer ◽  
Morphological Properties ◽  
Terrestrial Environment ◽  
Ir Camera ◽  
Stable Conditions ◽  
James Ross Island ◽  
Atmospheric Factors

Five lakes on the northernmost tip of James Ross Island (JRI), Ulu Peninsula, were selected to study their water temperature regime and relationship to atmospheric factors. Different genetic types of lakes were selected to cover not only influence of atmospheric parameters but also the morphology of lakes. Water temperature of all lakes showed strong similarities in the reaction to atmospheric factors no matter its genetic type or morphological properties, which were only second order factors shaping the general trends into more individual temporal patterns. All lakes are characterised by strong diurnal regime with maximum temperatures in late afternoon and minimum early morning. Most stable conditions were found in Monolith Lake and Triangular Lake, the first one with the biggest volume and regular inflow and outflow of water, the second one with semi-permanent ice cover protecting the water column from larger fluctuations caused by atmospheric factors. The most unstable environment was found in Shallow Lake, small shallow temporary lake with variable water level. Spatio-temporal issues of temperature relationships between water body and the terrestrial environment were shown with IR camera timelapse shooting on the example of Shallow Lake.

scholarly journals The distribution, abundance and population trends of gentoo, rockhopper and king penguins in the Falkland Islands

Oryx ◽  
1998 ◽  
Vol 32 (3) ◽  
pp. 223-232 ◽  
Author(s):  
M. Bingham
Keyword(s):  
World Wide ◽  
Austral Summer ◽  
Population Trends ◽  
King Penguin ◽  
Falkland Islands ◽  
Terrestrial Environment ◽  
Breeding Populations ◽  
Breeding Location ◽  
Penguin Species

The Falkland Islands are a globally important breeding location for seabirds, including penguins. The total breeding populations of three of the four main penguin species present in the Falklands were censused in the austral summer of 1995/96. The results for gentoo and rockhopper penguins suggest declines of about 43 and 90 per cent, respectively, since a similar census in 1932/33. Recent monitoring studies suggest that these declines are still continuing; research to investigate causes (which is likely to reflect changes in the marine, rather than terrestrial environment) is a high priority. In contrast, king penguin populations, currently c. 400 pairs, have increased steadily, by 700 per cent since 1980/81, in line with world-wide trends for this species.

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.

scholarly journals The effects of water temperature on the juvenile performance of two tropical damselfishes expatriating to temperate reefs

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Lucas D. Djurichkovic ◽  
Jennifer M. Donelson ◽  
Ashley M. Fowler ◽  
David A. Feary ◽  
David J. Booth
Keyword(s):  
Water Temperature ◽  
Growth Rates ◽  
Global Climate ◽  
Austral Summer ◽  
Reef Fishes ◽  
Performance Parameters ◽  
Feeding Rates ◽  
Lower Growth ◽  
Temperate Reefs ◽  
Eastern Australia

Abstract Ocean warming associated with global climate change is already inducing geographic range shifts of marine species. Juvenile coral reef fishes transported into temperate latitudes (termed ‘vagrant’ fishes) can experience winter water temperatures below their normal thermal minimum. Such environmental extremes may increase energetic costs for such fishes, resulting in reduced performance, which may be the governing factor that limits the potential for poleward range expansion of such fishes. This study compared the juvenile physiological performance and behaviour of two congeneric tropical damselfishes which settle during austral summer months within temperate eastern Australia: Abudefduf vaigiensis have an extended southern range, and lower threshold survival temperature than the congeneric A. whitleyi. Physiological and behavioural performance parameters that may be affected by cooler temperature regimes at higher latitudes were measured in aquaria. Lower water temperature resulted in reduced growth rates, feeding rates, burst escape speed and metabolic rates of both species, with significantly reduced performance (up to six-fold reductions) for fishes reared at 18 °C relative to 22 °C and 26 °C. However, A. whitleyi exhibited lower growth rates than A. vaigiensis across all temperatures, and lower aerobic capacity at the lowest temperature (18 °C). This difference between species in growth and metabolic capacity suggests that the extended southern distribution and greater overwintering success of A. vaigiensis, in comparison to A. whitleyi is related to thermal performance parameters which are critical in maintaining individual health and survival. Our results support previous findings in the region that water temperature below 22 °C represents a critical physiological threshold for tropical Abudefduf species expatriating into temperate south-eastern Australia.

scholarly journals Satellite imagery, a base line for glacier variation study on James Ross Island, Antarctica

1995 ◽  
Vol 21 ◽  
pp. 291-296 ◽  
Author(s):  
Pedro Skvarca ◽  
Helmut Rott ◽  
Thomas Nagler
Keyword(s):  
Satellite Imagery ◽  
Antarctic Peninsula ◽  
Warming Trend ◽  
Morphological Properties ◽  
Time Interval ◽  
Base Line ◽  
Glacier Variation ◽  
James Ross Island ◽  
Radar Satellite ◽  
Definition Of

Sequential visible and radar satellite imagery is used to document the fluctuations of 39 outlet glaciers on James Ross Island (JRI; 64° S, 58° W), Antarctic Peninsula. The monitoring time interval of 17.4 years extends from late 1975 until early 1993. The study is based on synergistic use of different sensors for monitoring glacier variations. The digitally enhanced Landsat TM images also allowed definition of boundaries between grounded and floating ice within Röhss Bay and detection of ice rumples, resulting in an improved measurement of the areal extent of JRI. In addition to glacier boundaries, the analyzed ERS-1 SAR images provide information on morphological properties of snow and ice. The satellite data show a general glacier retreat since 1975, resulting in clear decrease of overall glacier area on JRI. Of 39 glaciers measured, 33 glaciers retreated in the period 1975–93, 15 of which showed significant retreat in comparison to glacier size. This is in accordance with the pronounced atmospheric-warming trend recorded during the last two decades on the Antarctic Peninsula. The analysis of glacier areas on JRI thus provides a base line for detection of future changes.

Analysis of the water temperature regime of the Danube and its tributaries in Croatia

2008 ◽  
Vol 22 (7) ◽  
pp. 1014-1021 ◽  
Author(s):  
Ognjen Bonacci ◽  
Dušan Trninić ◽  
Tanja Roje-Bonacci
Keyword(s):  
Water Temperature ◽  
Temperature Regime

Inland diatoms from the McMurdo Dry Valleys and James Ross Island, Antarctica

Botany ◽  
2008 ◽  
Vol 86 (12) ◽  
pp. 1378-1392 ◽  
Author(s):  
R. M.M. Esposito ◽  
S. A. Spaulding ◽  
D. M. McKnight ◽  
B. Van de Vijver ◽  
K. Kopalová ◽  
...  
Keyword(s):  
Austral Summer ◽  
Mcmurdo Dry Valleys ◽  
Size Spectrum ◽  
Dry Valleys ◽  
Dominant Group ◽  
Lower Range ◽  
Glacial Ice ◽  
Dry Valley ◽  
James Ross Island ◽  
Harsh Conditions

Diatom taxa present in the inland streams and lakes of the McMurdo Dry Valleys and James Ross Island, Antarctica, are presented in this paper. A total of nine taxa are illustrated, with descriptions of four new species ( Luticola austroatlantica sp. nov., Luticola dolia sp. nov., Luticola laeta sp. nov., Muelleria supra sp. nov.). In the perennially ice-covered lakes of the McMurdo Dry Valleys, diatoms are confined to benthic mats within the photic zone. In streams, diatoms are attached to benthic surfaces and within the microbial mat matrix. One species, L. austroatlantica, is found on James Ross Island, of the southern Atlantic archipelago, and the McMurdo Dry Valleys. The McMurdo Dry Valley populations are at the lower range of the size spectrum for the species. Streams flow for 6–10 weeks during the austral summer, when temperatures and solar radiation allow glacial ice to melt. The diatom flora of the region is characterized by species assemblages favored under harsh conditions, with naviculoid taxa as the dominant group and several major diatom groups conspicuously absent.

Estuarine Ichthyoplankton Ecology in Relation to Hydrology and Zooplankton Dynamics in salt-wedge Estuary

1996 ◽  
Vol 47 (2) ◽  
pp. 99 ◽  
Author(s):  
GM Newton
Keyword(s):  
Water Temperature ◽  
Fish Larvae ◽  
River Estuary ◽  
Extended Period ◽  
Salt Wedge ◽  
Larval Stages ◽  
Black Bream ◽  
Stable Conditions ◽  
Maximum Water Temperature ◽  
High Concentrations

The ichthyoplankton assemblage of the Hopkins River estuary, Victoria, was dominated by estuarine taxa that included demersal (goby, gudgeon) and pelagic (black bream, estuary perch, anchovy) species. The two seasonal peaks in fish larvae abundance were related to (1) the spring/summer zooplankton increase that occurred after flooding of the estuary and was comprised predominantly of copepod nauplii, thereby providing a good prey field for very young fish larvae, and (2) the autumn zooplankton maxima, which would provide a wide selection of copepod stages and meroplankton and promote dietary partitioning and flexibility among older larval stages. The two peaks in fish larvae abundance occurred well before and well after the attainment of maximum water temperature in the estuary. Goby, gudgeon, estuary perch and anchovy larvae were in the plankton over an extended period coinciding with the more stable conditions of salt-wedge presence and maximum zooplankton densities. The spawning of black bream and anchovies in the estuary was clearly related to physical conditions, such as salinity and water temperature, and habitat-although spawning of both species also occurred at times of high concentrations of potential prey organisms for their larvae. Adults of all the above fish species appear to have evolved spawning strategies that are adapted to the average hydrological and biological conditions in the estuary that would lead to the enhanced survival of their larvae. With the exception of the black bream, it appears that a ubiquitous and prolonged rather than a synchronous and confined spawning strategy is more widely used by estuarine-spawning fishes in the Hopkins River estuary. This type of spawning strategy, combined with the generally high density of food available to fish larvae in estuaries, suggests that the match-mismatch hypothesis of Cushing may be less relevant in the estuarine than in the marine environment.

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