scholarly journals Regression relations and long-term water-quality constituent concentrations, loads, yields, and trends in the North Fork Ninnescah River, south-central Kansas, 1999–2019

2021 ◽  
Author(s):  
Ariele R. Kramer ◽  
Brian J. Klager ◽  
Mandy L. Stone ◽  
Patrick J. Eslick-Huff
Keyword(s):  
Water Quality ◽  
The North ◽  
South Central ◽  
North Fork ◽  
Regression Relations

scholarly journals Long-term associations and insights on social structure of the Humpback whales in Prince William Sound, Alaska

2020 ◽  
Author(s):  
Olga von Ziegesar ◽  
Shelley Gill ◽  
Beth Goodwin
Keyword(s):  
Social Structure ◽  
Feeding Habits ◽  
North Pacific Ocean ◽  
Small Population ◽  
Population Characteristics ◽  
Humpback Whales ◽  
Prince William Sound ◽  
The North ◽  
South Central

AbstractHumpback whale (Megaptera novaeangliae) social structure is more complex than previously thought. Because of the fluid “fission-fusion” nature of their relationships: individuals foraging, traveling, and socializing with a number of animals, where associations form and are broken numerous times, little has been confirmed about their long-term associations. Humpback whales of the North Pacific Ocean migrate annually between tropical breeding areas to northern latitudes where they congregate and feed. The purpose of this study was to explore the social and feeding habits of the summer population of humpback whales returning to Prince William Sound (PWS) in the south central coast of Alaska. Fluke photographs of pigmentation patterns were used to document individual whales between the years 1983 and 2009 to determine, population characteristics, reproductive rates, long-term associations, feeding habits and spatial partitioning. During the 27 year study period there were 3,017 encounters with 405 unique whales. Forty of these whales (9.88%) had long sighting histories, showing strong site fidelity. Association indices for all pairs of whales were calculated. Long-lasting associations were found between thirty-two of the forty whales. Two distinct groups were determined by the highest association coefficients. Although the overall ranges of the two groups overlapped, they did not often mingle and offspring did not join their maternal group. All but two females had enduring bonds with at least one male. Associate males were sometimes found at a distance from others of their “clan” and would rejoin periodically. Two whales from one of these clans were found together in Hawaiian waters, a male escorting a female with a newborn calf, suggesting these long lasting associations endure through migration and into the southern breeding areas. Optimal observation conditions of a small population of humpback whales in sheltered waters allowed the discovery of two social groups enduring almost three decades.

Terrain Geochemistry Surveys, Permafrost Studies, and Arctic Limnology, District of Keewatin, N.W.T.: Implications for Water Quality Monitoring in the North

1987 ◽  
Vol 22 (4) ◽  
pp. 505-517
Author(s):  
Tom W.D. Edwards ◽  
R.A. Klassen ◽  
W.W. Shilts
Keyword(s):  
Water Quality ◽  
Lake Sediments ◽  
Mineral Exploration ◽  
Surface Water Quality ◽  
Water Quality Monitoring ◽  
Quality Monitoring ◽  
The North ◽  
South Central ◽  
Geochemical Variations ◽  
Arctic Limnology

Abstract Geochemical studies and surveys conducted by the Geological Survey of Canada have provided considerable information about the natural geochemical variations in glacial drift, lake sediments, and lake waters in south-central District of Keewatin. In addition to their intended contribution to mineral exploration, these activities yielded much basic background data that may be applied to the planning of water quality monitoring programs in the region. Studies of permafrost features, and arctic limnology have furnished knowledge about natural geomorphic and diagenetic processes that influence surface water quality. Cryoturbation, on land and in the shallow areas of lakes underlain by permafrost, plays a major role in the transfer of particulate and dissolved drift constituents to surface waters. In spite of the abundance of mineral detritus on shore, profundal lake sediments are typically highly diatomaceous and possess conspicuous oxic surface layers that likely have a strong capacity to sequester both nutrients and trace metals.

DROUGHT AND RANGELAND GRASSHOPPER SPECIES DIVERSITY

1994 ◽  
Vol 126 (4) ◽  
pp. 1075-1092 ◽  
Author(s):  
W.P. Kemp ◽  
M.M. Cigliano
Keyword(s):  
Species Richness ◽  
Central Region ◽  
Resource Limitation ◽  
Extreme Drought ◽  
Severe Drought ◽  
Grasshopper Species ◽  
Drought Intensity ◽  
The North ◽  
South Central

AbstractRangeland grasshopper species richness was monitored at 10 sites in Montana, U.S.A., during 1986 through 1992, which included an extreme drought year (1988). We observed significant post-1988 drought reductions in rangeland grasshopper species richness in the eastern and south-central region of Montana where drought intensity has been increasing during the past 20 years. In the north-central region, which also experienced the 1988 drought but showed no long-term drought trend, we did not observe a post-drought reduction in overall rangeland grasshopper species richness. Thus, in terms of rangeland grasshopper species richness, the potential impact of a severe drought in a given year may depend on the timing of such an event within longer-term climatic cycles. Our findings suggest that as regional drought intensity increases temporally, there may be an increased likelihood that a single extreme drought year will not only have a profound impact on abundance but may also result in significant long-term reduction of grasshopper species richness. Our results support the hypothesis that resource limitation is a very important factor in structuring rangeland grasshopper communities in space and time.

Sign in / Sign up

Export Citation Format

Share Document