Experimental evidences for the use of two macroalgal species, Ascophyllum nodosum and Fucus vesiculosus as biomonitors of N sources

Stable isotope composition of brown macroalgae has been widely used to monitor N loading during the last decades but someof the required assumptionswhen using themto detect anthropogenic inputs remain untested. In this study several experiments were run with two key species, A. nodosum and F. vesicu...

ver descrição completa

Detalhes bibliográficos
Autores: González-Viana, Inés, Bode, Antonio, Bartolomew, Megan, Valiela, I.
Formato: artículo
Estado:Versión enviada para evaluación y publicación
Fecha de publicación:2015
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/316420
Acesso em linha:http://hdl.handle.net/10261/316420
Access Level:acceso abierto
Palavra-chave:stable isotopes
Medio Marino
Centro Oceanográfico de A Coruña
N
anthropogenic
experimental
macroalgae
fucaceae
DIN
Descrição
Resumo:Stable isotope composition of brown macroalgae has been widely used to monitor N loading during the last decades but someof the required assumptionswhen using themto detect anthropogenic inputs remain untested. In this study several experiments were run with two key species, A. nodosum and F. vesiculosus, to determine internal nitrogen isotope dynamics. First, the equilibration of the isotopic values of the different parts of the thallus of these species was tested by growing them under different water sources. Then, nitrate uptake capacity and N transport along the frond were tested by 15N enrichment experiments. The results indicate that although the growing tips had the highest uptake rates, older parts of the frond of both species have the capacity to incorporate N at low rates. No evidence of N transport along the thallus, from the tip to the basal segment of the frond or the conversewas found. These results showthat the growing tips of these macroalgae can be used to monitorN loadings at time scales from weeks (F. vesiculosus) to months (A. nodosum). The use of non-growing parts of the thallus to do retrospective studies cannot be recommended because of their measurable exchange of N with the surrounding water.