Tesis doctoral de María Del Mar Segura Noguera
Living organisms are composed by chemical elements, mainly c, h, o, n, p and s. The study of these essential elements is a powerful tool for comparing different levels of biological organization. For example, it is possible to compare elemental ratios (stoichiometry) or assess fluxes and mass balances within and between organelles, cells, whole ocean basins, or even the biosphere. The aim of this thesis is to establish the ratios between these chemical elements both within and outside phytoplankton cells from the catalan sea part of the nw mediterranean sea. oceanographic data from 28 cruises performed in the catalan sea between 1982 and 2003, amounting to 1361 stations, have been gathered. The quality of each of the key variables (inorganic nutrients, dissolved oxygen and chlorophyll a) was assessed and outlyers were examined for veracity. The most important difference in the analytical nutrient methodology was the occasional use of frozen samples. firstly, the ranges of nutrient concentrations, dissolved oxygen and chlorophyll a for the catalan sea, are described. Except for the phosphate and the dissolved oxygen, specific winter ranges for the other variables have to be defined, since the winter surface concentrations are particularly high due to deep water mixing. The mean concentration for the different water masses, and also the stoichiometry between nutrients and oxygen utilization (aou) have been calculated. At 500 m, where supposedly all the organic matter has been completely remineralized, the stoichiometry is: -o2:c:n:p:si=190:127:23:1:21. when comparing the average profiles of concentrations, obtained after the application of the quality controls, significant differences have been found between the continental shelf stations (less than 200 m of depth) and those of open sea (more than 200m): phosphate, nitrate + nitrite, silicate, and dissolved oxygen are lower in the shelf, whereas chlorophyll a and nitrite are higher. There are also seasonal variati
Datos académicos de la tesis doctoral «Relacio entre la distribucio de nutrients i oxigen dissolt i la composicio elemental del fitoplancton a la mar catalana (n-o mar mediterrania)«
- Título de la tesis: Relacio entre la distribucio de nutrients i oxigen dissolt i la composicio elemental del fitoplancton a la mar catalana (n-o mar mediterrania)
- Autor: María Del Mar Segura Noguera
- Universidad: Politécnica de catalunya
- Fecha de lectura de la tesis: 19/10/2007
Dirección y tribunal
- Director de la tesis
- Dolors Blasco Font De Rubinat
- Tribunal
- Presidente del tribunal: Antonio Cruzado alorda
- Alvarez salgado xose anton (vocal)
- Marrase i peña celia (vocal)
- fidel Echevarria navas (vocal)