摘要:

Two 10-month exposures of malathion and butoxyethanol ester of 2,4-D under continuous-flow conditions were made to determine the effect of these pesticides on reproduction and growth of fathead minnows, Pimephales promelas Rafinesque. Results show that 1/45 and 1/19 of the 96-hour median tolerance limit (TLm) concentrations of malathion and butoxyethanol ester, respectively, will not harm growth and reproduction of fathead minnows during continuous exposure. We suggest that these two fractions applied to TLmconcentrations determined for other species and other types of water should estimate accurately safe concentrations for other fishes to these pesticides.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1967)96[185:AMFEAT]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

Water temperature and dissolved oxygen content were measured vertically in Cultus Lake on 20 occasions and dissolved nitrogen eight times during 1961. The results showed the water in the region of the thermocline became supersaturated markedly as a consequence of warming during the spring and summer. The excess gas was below the extent of surface mixing and was held in solution by the hydrostatic pressure. In mid-July at a depth of 30 feet, oxygen was 126% and nitrogen 116% of air saturation. By mid-September at a depth of 50 feet, oxygen saturation was 94% and nitrogen 110% of air saturation. Oxygen was liberated by photosynthesis in the epilimnion and upper portion of the thermocline, and consumed in the lower part of the thermocline and the upper hypolimnion. Thus nitrogen supersaturation could not be diagnosed by measurement of dissolved oxygen alone. Nitrogen supersaturation is discussed in relation to the use of lake water for hatchery culture of fish.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1967)96[194:SOLWWA]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

A study was made of the effect of trout predation upon the crayfish population of a marl lake. The study provided a measurement of the efficiency of energy transfer between trophic levels in the lake and the assessment of the relative importance of fish predation as an interspecies interaction.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1967)96[202:EOBTPO]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

摘要:

The elimination from the Giant Grebe Refuge, Lake Atitlan, Guatemala, of fish especially largemouth bass (Micropterus salmoides) which is the predator of the rare Giant Pied-billed Grebe chick (Podilymbus gigas), using the new fish toxicant antimycin is described.

ISSN:0002-8487    

DOI:10.1577/1548-8659(1967)96[210:EOFITG]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/1548-8659(1967)96[214:TOOAKC]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/1548-8659(1967)96[216:EAEOIG]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/1548-8659(1967)96[218:FOTFDA]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/1548-8659(1967)96[220:IOCMOF]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/1548-8659(1967)96[222:WRAAMO]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor

ISSN:0002-8487    

DOI:10.1577/1548-8659(1967)96[223:AAGOPO]2.0.CO;2

出版商:Taylor & Francis Group    

年代:1967

数据来源: Taylor