Trophic niche partitioning of five skate species of genus Bathyraja in northern and central Patagonia, Argentina.

Overexploitation of marine communities can lead to modifications in the structure of the food web and can force organisms like elasmobranchs to change their feeding habits. To evaluate the impact that fisheries have on food webs and on the interactions between species, it is necessary to describe and quantify the diet of the species involved and follow it through time. This study compares the diet of five skate species using the data obtained from the by-catch of the Argentine hake (Merluccius hubbsi) fishery in north and central Patagonia, Argentina.

Evaluation of a fibre optic device in solution equilibria studies. Application to 3-hydroxybenzoic acid ionization.

The use of a fibre optic device for spectrophotometric measurements in solution equilibria studies is presented. In particular the precision obtainable with such equipment is evaluated as a function of different experimental conditions, such as path length, averaging time and stirring of the solution. Analysis of 3-hydroxybenzoic acid ionization is presented to assess the results obtained in the study of an equilibrium system.