6 resultados para Oratory--Students--17th century--Sources
em Aquatic Commons
Resumo:
The Arctic charr of the British Isles are all non-migratory and are near their most southernmost range. Windermere is one of the few lowland lakes at southerly latitudes to contain a substantial proportion of Arctic charr. The first recorded mention of charr in Windermere was made around 1540 but it was not till the 17th century that different "sons" of charr were recognized, based on differences in their breeding behaviour. In the 1960's, the presence of two distinct populations, autumn spawners and spring spawners were discovered. In the 1980's it was shown that there were at least four races of charr in Windermere, based on genetic characteristics. Recently, the lake has changed due to inputs of phosphorus from treated sewage released into the lake resulting in eutrophication particularly in the south basin. Since the mid-1980's the numbers of charr caught in the south basin have declined.
Resumo:
A distinct, 1- to 2-cm-thick flood deposit found in Santa Barbara Basin with a varve-date of 1605 AD ± 5 years testifies to an intensity of precipitation that remains unmatched for later periods when historical or instrumental records can be compared against the varve record. The 1605 AD ± 5 event correlates well with Enzel's (1992) finding of a Silver Lake playa perennial lake at the terminus of the Mojave River (carbon-14-dated 1560 AD ± 90 years), in relative proximity to the rainfall catchment area draining into Santa Barbara Basin. According to Enzel, such a persistent flooding of the Silver Lake playa occurred only once during the last 3,500 years and required a sequence of floods, each comparable in magnitude to the largest floods in the modern record. To gain confidence in dating of the 1605 AD ± 5 event, we compare Southern California's sedimentary evidence against historical reports and multi-proxy time-series that indicate unusual climatic events or are sensitive to changes in large-scale atmospheric circulation patterns. The emerging pattern supports previous suggestions that the first decade of the 17th century was marked by a rapid cooling of the Northern Hemisphere, with some indications for global coverage. A burst of volcanism and the occurrence of El Nino seem to have contributed to the severity of the events. The synopsis of the 1605 AD ± 5 years flood deposit in Santa Barbara Basin, the substantial freshwater body at Silver Lake playa, and much additional paleoclimatic, global evidence testifies for an equatorward shift of global wind patterns as the world experienced an interval of rapid, intense, and widespread cooling.
Resumo:
This presentation will describe the use of online forums in Moodle, a course management system, to teach students to evaluate both print and electronic reference sources. For two semesters I have created an online forum called the Fishing Hole Scouting Report for an in-class exercise. Students are given 2-3 background questions and told to find the answers using both a library-approved reference source and Wikipedia. Students then evaluate the reference source for effectiveness and ease of use, compared to Wikipedia, and post their comments in the forum to share with the class. I will highlight the educational benefits of using Moodle forums for this purpose and discuss best practices for selecting the most effective sources and questions.
Resumo:
The 19th century commercial ship-based fishery for gray whales, Eschrichtius robustus, in the eastern North Pacific began in 1846 and continued until the mid 1870’s in southern areas and the 1880’s in the north. Henderson identified three periods in the southern part of the fishery: Initial, 1846–1854; Bonanza, 1855–1865; and Declining, 1866–1874. The largest catches were made by “lagoon whaling” in or immediately outside the whale population’s main wintering areas in Mexico—Magdalena Bay, Scammon’s Lagoon, and San Ignacio Lagoon. Large catches were also made by “coastal” or “alongshore” whaling where the whalers attacked animals as they migrated along the coast. Gray whales were also hunted to a limited extent on their feeding grounds in the Bering and Chukchi Seas in summer. Using all available sources, we identified 657 visits by whaling vessels to the Mexican whaling grounds during the gray whale breeding and calving seasons between 1846 and 1874. We then estimated the total number of such visits in which the whalers engaged in gray whaling. We also read logbooks from a sample of known visits to estimate catch per visit and the rate at which struck animals were lost. This resulted in an overall estimate of 5,269 gray whales (SE = 223.4) landed by the ship-based fleet (including both American and foreign vessels) in the Mexican whaling grounds from 1846 to 1874. Our “best” estimate of the number of gray whales removed from the eastern North Pacific (i.e. catch plus hunting loss) lies somewhere between 6,124 and 8,021, depending on assumptions about survival of struck-but-lost whales. Our estimates can be compared to those by Henderson (1984), who estimated that 5,542–5,507 gray whales were secured and processed by ship-based whalers between 1846 and 1874; Scammon (1874), who believed the total kill over the same period (of eastern gray whales by all whalers in all areas) did not exceed 10,800; and Best (1987), who estimated the total landed catch of gray whales (eastern and western) by American ship-based whalers at 2,665 or 3,013 (method-dependent) from 1850 to 1879. Our new estimates are not high enough to resolve apparent inconsistencies between the catch history and estimates of historical abundance based on genetic variability. We suggest several lines of further research that may help resolve these inconsistencies.
Resumo:
William Francis Thompson (1888–1965) was a preeminent fishery scientist of the early to mid twentieth century. Educated at Stanford University in California (B.A. 1911, Ph.D. 1930), Thompson conducted pioneering research on the Pacific halibut, Hippoglossus stenolepis, from 1914 to 1917 for the British Columbia Provincial Fisheries Department. He then directed marine fisheries research for the State of California from 1917 to 1924, was Director of Investigations for the International Fisheries Commission from 1924 to 1939, and Director of the International Pacific Salmon Fisheries Commission from 1937 to 1942. He was also Director of the School of Fisheries, University of Washing-ton, Seattle, from 1930 to 1947. Thompson was the founding director in 1947 of the Fisheries Research Institute at the University of Washington and served in that capacity until his retirement in 1958. He was a dominant figure in fisheries research of the Pacific Northwest and influenced a succession of fishery scientists with his yield-based analysis of fishery stocks, as opposed to studying the fishes’environment. Will Thompson was also a major figure in education, and many of his former students attained leadership positions in fisheries research and administration.
Resumo:
The marine invertebrates of North America received little attention before the arrival of Louis Agassiz in 1846. Agassiz and his students, particularly Addison E. Verrill and Richard Rathbun, and Agassiz's colleague Spencer F. Baird, provided the concept and stimulus for expanded investigations. Baird's U.S. Commission of Fish and Fisheries (1871) provided a principal means, especially through the U.S. Fisheries Steamer Albatross (1882). Rathbun participated in the first and third Albatrossscientific cruises in 1883-84 and published the fist accounts of Albatross parasitic copepods. The first report of Albatross planktonic copepods was published in 1895 by Wilhelm Giesbrecht of the Naples Zoological Station. Other collections were sent to the Norwegian Georg Ossian Sars. The American Charles Branch Wilson eventually added planktonic copepods to his extensive published works on the parasitic copepods from the Albatross. The Albatross copepods from San Francisco Bay were reported upon by Calvin Olin Esterly in 1924. Henry Bryant Bigelow accompanied the last scientific cruise of the Albatross in 1920. Bigelow incorporated the 1920 copepods into his definitive study of the plankton of the Gulf of Maine. The late Otohiko Tanaka, in 1969, published two reviews of Albatross copepods. Albatross copepods will long be worked and reworked. This great ship and her shipmates were mutually inspiring, and they inspire us still.