The Tennessee River had a long and colorful history of transporting Native Americans, settlers, armies, and cargo of all types in 1700s and 1800s. The headwaters of the Tennessee River, the largest tributary of the Oh...The Tennessee River had a long and colorful history of transporting Native Americans, settlers, armies, and cargo of all types in 1700s and 1800s. The headwaters of the Tennessee River, the largest tributary of the Ohio River, originates in the Appalachian Mountains of eastern United States. Created by the confluence of the Holston and French Broad rivers at Knoxville, the Tennessee River flows approximately 1049 km to Paducah, Kentucky where it drains into the Ohio River. This paper highlights how the landscape and geological resources of the Tennessee River and tributaries watershed contributed to the successful economic development of this historical region of North America. The Tennessee River is one of the most biologically diverse freshwater systems in the United States. Environmental challenges included an unsuccessful attempt to keep invasive species, such as the Asian carp, out of the Tennessee River and the Kentucky Lake. The 1049 river kilometer Tennessee River regional trail system with charter River Towns was designed to promote recreational tourism, increase the use of the Tennessee River and to create generations of people who care about the river and are willing to provide environmental stewardship of the watershed resources and protect the river.展开更多
Microcystis bloom, one of the most objectionable characteristics of eutrophication in tropical and subtropical waters, occurred in Donghu Lake (East Lake) of Wuhan every summer from the 1970s up to 1984, but from 1985...Microcystis bloom, one of the most objectionable characteristics of eutrophication in tropical and subtropical waters, occurred in Donghu Lake (East Lake) of Wuhan every summer from the 1970s up to 1984, but from 1985 up to now failed to occur there. The cause of its disappearance remained in obscurity until recently. In situ enclosure experiments in the lake for three years showed that the stocking of the filter-feeding silver carp (Hypophthalmichthys molitrix) and big-head carp (Aristichthys nobilis) played a decisive role in eliminating Microcystis bloom from the lake; but that recurrence of the bloom is possible under certain conditions. This paper presents the details and the results of enclosure experiments. The authors’ analysis of fish biomass data obtained by echo-sounding and the fishery production of the lake over the years, revealed that the recurrence of Microcystis bloom can be prevented so long as the combined biomass of silver carp and big-head carp remains at or exceeds 50 g per cubic meter of lakewater, as was the case in the lake’s 1985 fish yield of 1015 t.展开更多
文摘The Tennessee River had a long and colorful history of transporting Native Americans, settlers, armies, and cargo of all types in 1700s and 1800s. The headwaters of the Tennessee River, the largest tributary of the Ohio River, originates in the Appalachian Mountains of eastern United States. Created by the confluence of the Holston and French Broad rivers at Knoxville, the Tennessee River flows approximately 1049 km to Paducah, Kentucky where it drains into the Ohio River. This paper highlights how the landscape and geological resources of the Tennessee River and tributaries watershed contributed to the successful economic development of this historical region of North America. The Tennessee River is one of the most biologically diverse freshwater systems in the United States. Environmental challenges included an unsuccessful attempt to keep invasive species, such as the Asian carp, out of the Tennessee River and the Kentucky Lake. The 1049 river kilometer Tennessee River regional trail system with charter River Towns was designed to promote recreational tourism, increase the use of the Tennessee River and to create generations of people who care about the river and are willing to provide environmental stewardship of the watershed resources and protect the river.
文摘Microcystis bloom, one of the most objectionable characteristics of eutrophication in tropical and subtropical waters, occurred in Donghu Lake (East Lake) of Wuhan every summer from the 1970s up to 1984, but from 1985 up to now failed to occur there. The cause of its disappearance remained in obscurity until recently. In situ enclosure experiments in the lake for three years showed that the stocking of the filter-feeding silver carp (Hypophthalmichthys molitrix) and big-head carp (Aristichthys nobilis) played a decisive role in eliminating Microcystis bloom from the lake; but that recurrence of the bloom is possible under certain conditions. This paper presents the details and the results of enclosure experiments. The authors’ analysis of fish biomass data obtained by echo-sounding and the fishery production of the lake over the years, revealed that the recurrence of Microcystis bloom can be prevented so long as the combined biomass of silver carp and big-head carp remains at or exceeds 50 g per cubic meter of lakewater, as was the case in the lake’s 1985 fish yield of 1015 t.
