摘要:

Massive floating and benthic mats of the filamentous blue-green alga,Lyngbya wollei, occlude small lakes and shallow coves of large reservoirs, especially in the southeastern United States.In situstanding crops (up to 6.66 kg fresh weight m−2), seasonal vertical distribution (surface, benthic and mid-depth suspended) and metabolic characteristics ofL. wolleimats in Marten's Pond, S.C. are described and compared with midsummer infestations in three other southeastern impoundments. The dense floating mats which are the most visible manifestation of infestations limit irradiance available to subsurface filaments; less than 2% of incident irradiance penetrates surface mats. Surface filaments containing minimal chlorophyll a and abundant myxoxanthophyll are photosynthetically inactive, whereas subsurface filaments having greater concentrations of phycobilins and chlorophyll a are most active in photosynthesis.L. wolleiis perennial because virtually all of the summer biomass overwinters on the lake sediments. The bulk ofL. wolleibiomass (> 64%) in Marten's Pond remained subsurface throughout the year.L. wolleipersists and grows in this subsurface environment due to the abundant phycobilin pigments, adapted for interception of a broad spectrum of low intensity light and the low photosynthetic light compensation point (32 μ Einsteins m−2sec−1) of healthy filaments.

ISSN:1040-2381    

DOI:10.1080/07438149109354259

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The compilation of international handbooks on the management of eutrophication and nonpoint source pollution posed a number of conceptual problems, not the least of which was the determination of relevant and meaningful methods to span the spectrum of developed and developing world applications. Given that most of the lake management strategies currently being employed throughout the world are based in whole or in part on methods developed in Europe or North America, this problem is a significant one. Not only are there measurable limnological differences between waterbodies in the temperate zone versus waterbodies in the tropics/subtropics, but also differences in the levels of technical skills and “hardware” exist between these regions. Many developing countries suffer badly from loss of skills to the developed world and must buy goods and services in the field of lake management. Hence, to be successful, both the investigations and implementations must take cognizance of the climatic and techno-socio-economic rigors imposed by the developing world setting. This paper briefly reviews some of the distinguishing characteristics of society and waterbodies in the tropical developing countries, before examining a selection of appropriate strategies for managing eutrophication, using illustrative examples from southern Africa. Such strategies could also have application to small scale projects in the developed world where similar cost constraints often apply.

ISSN:1040-2381    

DOI:10.1080/07438149109354260

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

ISSN:1040-2381    

DOI:10.1080/07438149109354261

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Lake and reservoir managers, as well as affected citizen groups, have increasingly recognized the need for extensive watershed-level land use and water quality data in developing effective lake management strategies. Water quality data, in particular, from lake or reservoir tributaries is essential for identifying and quantifying point and nonpoint sources of pollutants. The realization of these informational needs, coupled with the personnel and financial resource constraints that limit most governmental agency monitoring programs, have helped to spawn a multitude of citizen-organized volunteer water quality monitoring programs. This paper describes a unique volunteer-based monitoring network, which in cooperation with a university laboratory, is developing laboratory monitoring data using EPA-certified methods at minimal cost. The program consists of 45 stream sites, each of which is staffed by two or more volunteers. The network is sampled monthly for 12 parameters including various nutrients and heavy metals. This program appears to have the unique capacity of providing STORET-acceptable data while simultaneously functioning as a highly visible quality education/awareness program within the local community.

ISSN:1040-2381    

DOI:10.1080/07438149109354262

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

High resolution, site specific tributary and lake water column data are required for the model calibration and verification phase of the Shipshewana Lake restoration project in north-central Indiana. The collection of these data would be prohibitively expensive without local commitment in the form of a lay monitoring program. Lay volunteers were trained in the operation of basic limnological instrumentation, sample collection, data recording, and sample shipping. Monitoring consisted of bi-monthly water quality monitoring and sampling at 11 stations in the lake and its tributaries, along with storm samples collected at 11 stations throughout the watershed. A total of 551 water samples were targeted for collection over a 12 month period. The results of the first six months of monitoring are presented along with a summary of cost-savings, difficulties encountered, and keys to the success of this program.

ISSN:1040-2381    

DOI:10.1080/07438149109354263

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Lakes in Dane County suffer from cultural eutrophication. Many attempts designed to solve water quality problems have failed. While technical solutions appear feasible, institutional arrangements have hampered progress in pushing back the clock on cultural eutrophication. The latest effort to address these institutional weaknesses produced the Dane County Lakes and Watershed Commission. At the same time, the County was also provided with new authority and financing tools for water resource problems. The effectiveness of the new Commission and the powers granted to the Dane County Board of Supervisors are evaluated in terms of seven lake management factors. The new arrangements appear to address six out of these seven factors fairly well. While the new institution offers much promise, the County faces the challenge of sustaining the political will to make long-term progress in reversing cultural eutrophication.

ISSN:1040-2381    

DOI:10.1080/07438149109354264

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor