40 resultados para CABRERA, LYDIA, 1899-1991

em Aquatic Commons


Relevância:

20.00% 20.00%

Publicador:

Resumo:

(PDF contains 120 pages.)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

[pdf has 107 pages]

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study owes its inception to the wisdom and experience of the staff of the Northeast Fisheries Science Center who, after several decades of surveys in the New York Bight, recognized a unique opportunity to capitalize on the decision to stop ocean dumping of sewage sludge and designed an innovative field study to evaluate effects on living marine resources and their habitats. For decades ocean dumping was viewed as a cheap and effective means for disposal of wastes generated by urbanized coastal areas. Even after the 12-mile site was closed, sewage sludge continued to be dumped at Deepwater Dumpsite 106. The 6-mile site off the NewJersey coast is still used as a dumpsite for dredged material from New York Harbor areas. Discussions continue on the propriety of using the deep ocean spaces for disposal of a variety of material including low level radioactive wastes. Consequently, managers are still faced with critical decisions in this area. It is to be hoped that the results from the 12-mile study will provide the necessary information on which these managers can evaluate future risks associated with ocean waste disposal. (PDF file contains 270 pages.)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Silver King Creek, Alpine County, is the native range of the Federally-threatened Paiute cutthroat trout, Oncorhynchus clarki seleniris. Paiute cutthroat currently inhabit Coyote Valley and Corral Valley creeks, which are tributaries to Silver King Creek below Llewellyn Falls, and also Silver King Creek and tributaries aboye Llewellyn Falls. Rainbow trout, O. mykiss, were introduced into the basin during 1949 and became hybridized with Paiute cutthroat. Chemical treatments attempted by the California Department of Fish and Game (CDFG) in 1964 and 1976 failed to eliminate hybrid trout. A chemical treatment project was again conducted by the CDFG from 1991 through 1993 to eliminate hybrid trout from within the range of Paiute cutthroat. This report presents a summary of events for the first two years of the Silver King Paiute Cutthroat Trout Restoration Project; a more thorough analysis is made of the third and final year of the project. (PDF contains 39 pages.)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This report covers the 39th annual inventory of chinook salman, Oncorhynchus tshawytscha, spawner populations in the Sacramento-San Joaquin River system." It is a compilation of reports estimating the fall-, winter-, late-fall-, and spring-run salman spawner populatiens fer streams which were surveyed. Estimates were made from counts of fish entering hatcheries and migrating past dams, from surveys of dead and live fish and redds on spawning areas, and from aerial counts. The estimated 1991 total escapement of chinook salmon in the Central Valley was 147,080 fish. This total consisted of 132,571 fall-, 5,921 spring-, 190 winter-, and 8,398 late-fall-run spawners. All of the spring-, late-fall-, and winter-run salmon were estimated to be in the Sacramento River system, while 1,176 fish of the fall run were in the San Joaquin River system. Spawner populations in all individual tributaries (except the American River) and the Sacramento River mainstem were lower than in 1990; but it should be noted that fall run populations in the Feather and Yuba rivers, two of the larger tributaries, were not surveyed that year. The winter run in the mainstem Sacramento River was at a record low level. (PDF contains 42 pages.)

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The California Department of Fish and Game's Natural Stocks Assessment Project (NSAP) collected water quality data at high tides on a monthly basis from February 1991 to October 1994, and during low tides from March 1992 to June 1994 in the Klamath River estuary to describe water quality conditions. NSAP collected data on water temperature, dissolved oxygen, salinity, depth of saltwedge, and Klamath River flow. Klamath River flows ranged from 44.5 cubic meters per second (1570 cfs) in August 1994 to 3832.2 cubic meters per second (135,315 cfs) in March 1993. Saltwater was present in the estuary primarily in the summer and early fall and generally extended 2 to 3 miles upstream. Surface water temperatures ranged from 6-8° C in the winter to 20-24° C in the summer. Summer water temperatures within the saltwedge were generally 5 to 8° C cooler than the surface water temperature. Dissolved oxygen in the estuary was generally greater than 6 to 7 ppm year-round. A sand berm formed at the mouth of the river each year in the late summer or early fall which raised the water level in the estuary and reduced tidal fluctuation so that the Klamath estuary became essentially a lagoon. I hypothesize the formation of the sand berm may increase the production of the estuary and help provide favorable conditions for rearing juvenile chinook salmon.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Das bereits vom ehemaligen Institut für Hochseefischerei, Rostock, routinemäßig durchgeführte Heringslarvenprogramm im Greifswalder Bodden wird als Beitrag zur Bestandsschätzung des Rügenschen Frühjahrsherings (RFH) zunehmend unter ökologischen Gesichtspunkten im Institut für Ostseefischerei (IOR) in Kooperation mit der Universität Rostock (Fachbereich Biologie) weitergeführt. Die quantitative Larvenanalyse ermöglicht über den Anteil des aus dem Greifswalder Bodden stammenden Nachwuchses eine Voraussage über den Erfolg der in einem weitaus größeren Seegebiet (ICES SD 22+24) produzierten Nachwuchsjahresklassen. Vorliegende Publikation dokumentiert erste Ergebnisse hinsichtlich der Heringslarvenverteilung im Saisonverlauf 1991 und 1992.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Seit den vierziger Jahren ist bekannt, dass in der Irminger See und nordwestlich vom Reykjanes-Rücken (ICES-Gebiet XIV b und teilweise XII) ein Rotbarschbestand anzutreffen ist, der wegen seiner pelagischen Lebensweise auch als "ozeanischer Bestand" bezeichnet wird.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

An obituary of the limnologist G.E. Hutchinson is given.