Learn More
In order to evaluate short-term and long-term effects of fish manipulation in shallow, eutrophic lakes, empirical studies on relationships between lake water concentration of total phosphorus (P) and the occurrence of phytoplankton, submerged macrophytes and fish in Danish lakes are combined with results from three whole-lake fish manipulation experiments.(More)
Analysis of Danish lakes showed that both mean winter and mean summer concentrations of lake water total phosphorus in the trophogenic zone correlated negatively with the total iron to total phosphorus ratio (Fe:P) in surface sediments. No correlation was found between the water total phosphorus concentration and either the sediment phosphorus concentration(More)
No recovery was recorded in the shallow and eutrophic Lake Væng, Denmark, after a sewage diversion in 1981, due to an internal phosphorus loading and a dominance of planktivorous fish. In order to improve lake water quality by means of biomanipulation, a total of 2.5 tons of bream (Abramis brama) and roach (Rutilus rutilus) was removed during 1986 and the(More)
Internet data traffic capacity is rapidly reaching limits imposed by optical fiber nonlinear effects. Having almost exhausted available degrees of freedom to orthogonally multiplex data, the possibility is now being explored of using spatial modes of fibers to enhance data capacity. We demonstrate the viability of using the orbital angular momentum (OAM) of(More)
Beams with polarization singularities have attracted immense recent attention in a wide array of scientific and technological disciplines. We demonstrate a class of optical fibers in which these beams can be generated and propagated over long lengths with unprecedented stability, even in the presence of strong bend perturbations. This opens the door to(More)
The use of fish manipulation as a tool for lake restoration in eutrophic lakes has been investigated since 1986 in three shallow, eutrophic Danish lakes. The lakes differ with respect to nutrient loading and nutrient levels (130–1000 µg P l−1, 1–6 mg N l−1). A 50% removal of planktivorous fish in the less eutrophic cyanobacteria-diatom dominated Lake Væng(More)
An international ring test involving 14 laboratories was organized on behalf of the Commission of the European Economic Communities (EEC) with the purpose of evaluating two proposed screening methods for assessment of biodegradability in seawater: (a) a shake flask die-away test based primarily on analysis of dissolved organic carbon and (b) a closed bottle(More)
  • P Crouzet ( Ifen, J Leonard, +9 authors J H Schultz Grafisk
Legal notice Neither the European Community, the European Environment Agency, nor any person or company acting on their behalf is responsible for the use which may be made of the information in this publication. The contents of this publication do not necessarily reflect the official opinions of the European Community, its institutions, or the international(More)
We propose a measurement protocol and parameter estimation algorithm to recover the powers and relative phases of each of the vector modes present at the output of an optical fiber that supports the HE₁₁, TE₀₁, HE₂₁, and TM₀₁ modes. The measurements consist of polarization filtered near-field intensity images that are easily implemented with standard(More)