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1

Digitale Medien

Effects on fisheries and waterbirds of raising water levels at Kerkini Reservoir, a Ramsar site in northern greece (1995)

Crivelli, A. J. ; Grillas, P. ; Jerrentrup, H. ; [weitere]

Springer

Environmental management 19 (1995), S. 431-443

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ISSN: 1432-1009

Schlagwort(e): Reservoir ; Fisheries ; Breeding and wintering waterbirds ; Raising water levels ; Habitat change

Quelle: Springer Online Journal Archives 1860-2000

Thema: Energietechnik

Notizen: Abstract A new, higher dam was installed at Kerkini Reservoir in 1982, causing habitat and landscape disruption. A decrease in the area of grassland and shallow water areas, the rapid disappearance of reedbeds, the appearance of beds ofNymphaea, and the disappearance of half the forest area were all observed between 1982 and 1991. With the new hydrological regime, a lacustrine system was created, with an extensive, rather deep (4–8 m), pelagic zone favorable for the development of coarse fish species throughout the year. After 1982, an increase in fishing effort and a change in the relative abundance of fish species in the catch, including the disappearance of eels and wels, were observed. The impact of the rise in the water level of breeding aquatic birds led to a general decline in species typical of marshy habitats in favor of species preferring deeper open water habitats. A decrease was recorded in bird species that feed largely on invertebrates and to a lesser extent fish (e.g., glossy ibis) and that require extensive shallow feeding areas. There was a decline in geese, whose nests were regularly flooded, and a major increase in piscivorous birds, particularly diving birds (e.g., cormorants), which prefer deeper open water and benefitted directly from the large increase in coarse fish biomass. The disappearance of birds breeding in flooded meadows (e.g., black-winged stilts) and of those restricted to reedbeds (e.g., marsh harrier) occurred from 1983. Over the same period, the changes in populations of wintering birds at Kerkini were different from those occurring in other wetlands in northern Greece. The changes recorded in the populations of wintering birds at Kerkini did not therefore result from overall regional trends but from the major habitat modifications that occurred to this wetland. As for breeding birds, strictly piscivorous species increased greatly as a result of the increased availability of fish, but also due to the appearance of many suitable night roosting sites (flooded trees) and to the great increase in the area of open water greater than 2 m deep. Today, Kerkini has become the most important breeding site in Greece for a majority of colonial waterbirds. In contrast, wintering shorebirds practically disappeared. The many changes recorded in the status of breeding and wintering birds at Kerkini can mostly be explained by the changes that occurred in the functioning of the ecosystem and in the habitat structure following the inauguration of the new hydrological regime. These changes did not all occur at the same time: some were immediate and others required a delay before they could be detected.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF02471984

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2

Digitale Medien

Impact of water control projects on fisheries resources in Bangladesh (1996)

Mirza, Monirul Qader ; Ericksen, Neil J.

Springer

Environmental management 20 (1996), S. 523-539

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ISSN: 1432-1009

Schlagwort(e): Water control ; Floodplain ; Fisheries ; Bangladesh ; Chandpur

Quelle: Springer Online Journal Archives 1860-2000

Thema: Energietechnik

Notizen: Abstract Bangladesh is a very flat delta built up by the Ganges—Brahmaputra—Meghna/Barak river systems. Because of its geographical location, floods cause huge destruction of lives and properties almost every year. Water control programs have been undertaken to enhance development through mitigating the threat of disasters. This structural approach to flood hazard has severely affected floodplain fisheries that supply the major share of protein to rural Bangladesh, as exemplified by the Chandpur Irrigation Project. Although the regulated environment of the Chandpur project has become favorable for closed-water cultured fish farming, the natural open-water fishery loss has been substantial. Results from research show that fish yields were better under preproject conditions. Under project conditions per capita fish consumption has dropped significantly, and the price of fish has risen beyond the means of the poor people, so that fish protein in the diet of poor people is gradually declining. Bangladesh is planning to expand water control facilities to the remaining flood-prone areas in the next 15–20 years. This will cause further loss of floodplain fisheries. If prices for closed-water fish remain beyond the buying power of the poor, alternative sources of cheap protein will be required.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF01474653

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3

Digitale Medien

Land loss in coastal Louisiana (U.S.A.) (1979)

Craig, N. J. ; Turner, R. E. ; Day, J. W.

Springer

Environmental management 3 (1979), S. 133-144

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ISSN: 1432-1009

Schlagwort(e): Coastal zone Management ; Fisheries ; Marshes ; Wetlands ; Louisiana

Quelle: Springer Online Journal Archives 1860-2000

Thema: Energietechnik

Notizen: Abstract This paper examines causes and consequences of wetland losses in coastal Louisiana. Land loss is a cumulative impact, the result of many impacts both natural and artificial. Natural losses are caused by subsidence, decay of abandoned river deltas, waves, and storms. Artificial losses result from flood-control practices, impoundments, and dredging and subsequent erosion of artificial channels. Wetland loss also results from spoil disposal upon wetlands and land reclamation projects. Total land loss in Louisiana's coastal zone is at least 4,300 ha/year. Some wetlands are converted to spoil banks and other eco-systems so that wetland losses are probably two to three times higher. Annual wetland losses in the Barataria Bay basin are 2.6% of the wetland area. Human activities are the principal determinants of land loss. The present total wetland area directly lost because of canals may be close to 10% if spoil area is included. The interrelationship between hydrology, land, vegetation, substrate, subsidence, and sediment supply are complicated; however, hydrologic units with high canal density are generally associated with higher rates of land loss and the rate may be accelerating. Some cumulative impacts of land loss are increased saltwater intrusion, loss of capacity to buffer the impact of storms, and large additions of nutrients. One measure of the impact is that roughly $8–17 × 106 (U.S.A.) of fisheries products and services are lost annually in Louisiana. Viewed at the level of the hydrologic unit, land loss transcends differences in local vegetation, substrate, geology, and hydrology. Land management should therefore focus at that level of organization. Proper guideline recommendations require an appreciation of the long-term interrelations of the wetland estuarine system.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF01867025

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4

Digitale Medien

Production of a fish taxocene in a Texas pond (1977)

Jones, Fredrick V. ; Pearson, William D. ; Fitzpatrick, Lloyd C.

Springer

Environmental biology of fishes 2 (1977), S. 241-259

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ISSN: 1573-5133

Schlagwort(e): Production ; Fisheries ; Population dynamics ; Energetics ; Fishes ; Competition

Quelle: Springer Online Journal Archives 1860-2000

Thema: Biologie

Notizen: Synopsis Production rates of seven species of fishes were determined for one year in a 0.95 ha pond. Total annual production of all fishes in the pond was 209 g m−2y−1 (after the subtraction of 16.2 g m−2y−1 of negative production). Over 90% of the production occurred in the months of June through September, with young-of-the-year fishes contributing 84% of the total. When Y of Y fishes shifted to benthic diets in the spring, the small biomass of benthos available could not sustain the large biomas of fish. Severe competition for the available food then resulted in decreased production rates for the entire fish taxocene.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00005993

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5

Digitale Medien

Fish communities in the African Great Lakes (1996)

Lowe-McConnell, Rosemary

Springer

Environmental biology of fishes 45 (1996), S. 219-235

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ISSN: 1573-5133

Schlagwort(e): Ecology ; Behaviour ; Evolution ; Cichlids ; Fisheries ; Conservation

Quelle: Springer Online Journal Archives 1860-2000

Thema: Biologie

Notizen: Synopsis Ecological conditions in tropical lacustrine systems are considered by focusing on the evolution, maintenance, exploitation and vulnerability of fish communities in the African Great Lakes. The exceptionally high biodiversities in the littoral/sublittoral zones of the very ancient, deep, clear, permanently stratified rift lakes Tanganyika and Malawi, are contrasted with the simpler systems in their pelagic zones, also with biodiversity in the much younger, shallower Victoria, the world's largest tropical lake.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00003090

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6

Digitale Medien

Ecology and fish catches in natural lakes of Benin, West Africa (1995)

Adite, Alphonse ; Thielen, Rudi

Springer

Environmental biology of fishes 43 (1995), S. 381-391

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ISSN: 1573-5133

Schlagwort(e): Fisheries ; Irrigation ; Reproductive seasonality ; Sarotherodon galilaeus ; Species richness ; Water quality

Quelle: Springer Online Journal Archives 1860-2000

Thema: Biologie

Notizen: Synopsis A preliminary study of the ecology and commercial fish catches was carried out in the Toho-Todougba, Ahouangan and Dati lakes (1500 ha) in southern Benin (West Africa) over a period of 18 consecutive months. Water quality, species richness, and the reproductive biology of the dominant species, Sarotherodon galilaeus, were examined. Unlike Lagoon Toho-Todougba, lakes Ahouangan and Dati are less favourable for fish production because of their high total iron content and their relative low pH. The study revealed the existence of 19 species belonging to eleven (11) families: 16 species in Lagoon Toho-Todougba,12 in Lake Ahouangan, and 7 in Lake Dati. Lakes Ahouangan and Dati had a relatively high faunal similarity whereas Lagoon Toho-Todougba exhibited a relatively low faunal similarity with the former systems. In Lagoon Toho-Todougba, six cichlid species were the most important component of the fishery: Sarotherodon galilaeus, Tilapia guineensis, T. zillii, T. mariae, Chromidotilapia guntheri, Hemichromis fasciatus. Three catfish species Chrysichthys auratus, Clarias agboyiensis, and Clarias lazera were harvested in low abundances. Some other fish, such as Polypterus senegalus senegalus, Protopterus annectens and Heterotis niloticus were captured sporadically, with H. niloticus appearing more consistently in catches than the others. Although not abundant, Gymnarchus niloticus and the African pike, Hepsetus odoe, were almost always present in the catches. Ctenopoma kingsleyae appeared only in Ahouangan. Some predatory species, such as Notopterus afer and Xenomystus nigri, are encountered only in lakes Ahouangan and Dati. In Lagoon Toho-Todougba, Sarotherodon galilaeus had a sex ratio (♂: ♀) of 0.49:1, and size at maturation was estimated as 12.3 cm TL. The spawning period extended from May to September with the peak occurring in July. Fecundity was correlated to log-body length (r = 0.74) and log-body weight (r = 0.76). Fish catches were estimated at 389 kg ha−1 year−1; about 73% of which was Sarotherodon galilaeus. The overexploitation of juvenile fish and the use of this lagoon for the irrigation of palm tree plantations have reduced fish recruitment and mean size.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00001173

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7

Digitale Medien

The Synthesis of [4-Carboranylalanine, 5-Leucine]-Enkephalin (Including an Improved Preparation of t-Butoxycarbonyl-L-o-carboranylalnine, New Derivatives of L-Propargylglycine, and a Note on Melanotropic and Opiate Receptor Binding Characteristics)This work was supported by research grants of the Swiss National Science Foundation and the Swiss Federal Institute of Technology. Abbreviations are according to the IUPAC-IUB Commission on Biochemical Nomenclature [1] and Houben-Weyl [2]: Car represents L-propargylglycine is and Pra L-propargylglycine. A former statement in the summary of [3] that L-propargylglycine is a new amino acid is incorrect; only its derivatives with protecting groups suitable for peptide synthesis were new. The free amino acid had been described earlier as the racemate [4] and as the individual enantiomers [5]. (1979)

Fauchère, Jean-Luc ; Leukart, Othmar ; Eberle, Alex ; [weitere]

New York, NY : Wiley-Blackwell

Helvetica Chimica Acta 62 (1979), S. 1385-1395

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ISSN: 0018-019X

Schlagwort(e): Chemistry ; Organic Chemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie

Notizen: The title compound, an analogue of [Leu5]-enkephalin with L-o-carboranylalanine replacing L-phenylalanine in position 4, was prepared by fragment condensation. The analogue has a 3-fold higher affinity for rat brain opiate receptors in the [3H]naloxone competition assay than natural [Leu5]-enkephalin. Like [Leu5]-enkephalin and Na-acetyl-[Leu5]-enkephalin, the N-terminal tripeptide fragment, H · Tyr-Gly-Gly · OH, had no melanotropic activity in the Rana pipiens frog skin assay.A convenient, direct synthesis of methyl t-butoxycarbonyl-L-propargylglycinate is described, and the 13C-NMR. spectra of L-o-carboranylalanine recorded. The procedure was extended to the preparation of BOC · Car-Leu · OMe from BOC · Pra-Leu · OMe. A number of new propargylglycine derivatives are reported.

Zusätzliches Material: 3 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/hlca.19790620502

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8

Digitale Medien

Phenylselenoacetaldehyde, a Useful Reagent for the Homologative Conversion of Halides to Phenylselenomethyl KetonesDedicated to Professor Edgardo Giovannini on his 70th anniversary (1979)

Baudat, Roger ; Petrzilka, Martin

New York, NY : Wiley-Blackwell

Helvetica Chimica Acta 62 (1979), S. 1406-1410

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ISSN: 0018-019X

Schlagwort(e): Chemistry ; Organic Chemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie

Notizen: The conversion of primary, secondary and vinylic halides to the two C-atoms homologated phenylselenomethyl ketones 8 is described. The method involves addition of the readily available phenylselenoacetaldehyde 5 to the Grignard reagents 9 and oxidation of the resulting β-hydroxy-selenides 10 (Scheme 3).

Zusätzliches Material: 1 Tab.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/hlca.19790620505

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9

Digitale Medien

Anil-Synthese. 20. Mitteilung19. Mitt. siehe [1].. Über die Herstellung von Stilbenyl-Derivaten des 1,2,4,-OxadiazolsHerrn Professor Dr. Dr. h.c. Edgardo Giovannini zum 70. Geburtstag gewidmet (1979)

Berger, Hanny ; Siegrist, Adolf Emil

New York, NY : Wiley-Blackwell

Helvetica Chimica Acta 62 (1979), S. 1411-1428

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ISSN: 0018-019X

Schlagwort(e): Chemistry ; Organic Chemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie

Notizen: Preparation of Stilbenyl Derivatives of 1,2,4-OxadiazolesSchiffs bases derived from 3- and 5-(p-formylphenyl)-phenyl-1,2,4-oxadiazoles and chloroanilines are reacted with various p-tolyl substituted aromatic heterocycles in the presence of dimethylformamide and potassium hydroxide to yield the corresponding heterocyclic substituted stilbenes (‘Anil synthesis’). The reactivity of 5-[4-(chlorophenylimino-methyl)phenyl]-3-phenyl-1,2,4-oxadiazoles is very low and side reactions will predominate.

Zusätzliches Material: 1 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/hlca.19790620506

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10

Digitale Medien

(Perhalogenmethylthio)heterocyclen. XIX. Mitt.: s. [1].. Säurekatalysierte Substitutionen an (Perchlorfluormethylthio)pyrrolen und deren agrobiologische Wirkung (1979)

Dorn, Silvia ; Eggenberg, Peter ; Gerstenberger, Michael R. C. ; [weitere]

New York, NY : Wiley-Blackwell

Helvetica Chimica Acta 62 (1979), S. 1442-1450

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ISSN: 0018-019X

Schlagwort(e): Chemistry ; Organic Chemistry

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie

Notizen: (Perhalomethylthio)heterocycles. XIX. Mitt.: s. [1]. . Acid-catalyzed substitutions on (perchlorofluoromethylthio)pyrroles and their agro-biological activitiesIn the presence of C4F9SO3H the (perhalomethylthio)pyrroles 1a-c react with Cl3-nFnCSCl (n = 1-3) to give mixtures of the 2,5- and 2,4-disubstituted pyrroles 2a-f and 3a-h. 2a and 3a react with CF3SCl (catalyst CF3SO3H) yielding 2,3,5-tris (trifloromethylthio)pyrrole (4a), which under similar conditions reacts further to give 2,3,4,5-tetrakis (trifluoromethylthio)pyrrole (5). As a by-product during the conversion of 3a to 4a 2,3,4-tris (trifluoromethylthio)pyrrole (4b) is formed. The pyrroles 2a, 4a and 5 form the mercury salts 6a-c; compound 5 yields also a silver salt 7. The 1H- and 19F-NMR. spectra are discussed and the agro-biological properties of the compounds investigated.

Zusätzliches Material: 4 Tab.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/hlca.19790620508

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