RT journal article
T1 Elevated ammonium concentrations and low light form a dangerous synergy for eelgrass Zostera marina
A1 Morten F., Pedersen
A1 Fernando G., Brun
A1 Villazan, Beatriz
A1 Vergara Oñate, Juan José
A2 Biología
K1 Dissolved inorganic nitrogen
K1 Light
K1 Nitrogen metabolism
K1 Carbon reserves
K1 Seagrass
K1 Eutrophication
AB We studied the effect of ecologically relevant ammonium concentrations and light onseveral morphological and physiological properties, nitrogen metabolism and carbon reserves ofeelgrass Zostera marina L. Eelgrass was grown under mesocosm conditions at 3 levels of ammoniumenrichment (target concentrations of 0, 10 and 25 μM) and 2 levels of light (low and highlight). High ammonium supply combined with low light had a negative effect on several morphologicaland physiological response parameters, while no such effects were found when ammoniumwas supplied under high light. N enrichment caused an increase in the content of total N,intracellular ammonium, free amino acids and residual N in the plants and this response was morepronounced under low-light conditions than under high light. The soluble proteins content de -crea sed, in contrast with external ammonium enrichment. The accumulation of free amino acidsand residual N in NH4+-enriched plants was followed by a substantial drop in carbohydratereserves (sucrose and starch), which was larger in plants grown under low-light conditions. Ourresults indicate that N enrichment increases the demand for C skeletons and energy, and that photosynthesiscannot supply enough C and energy to cover that demand under low-light conditions.Eelgrass plants exposed to reduced light conditions, for example close to their depth limit or whencovered by drift macroalgae, may thus be especially susceptible to enhanced ammonium concentrations.Our study demonstrates that ammonium toxicity may explain why eelgrass and other seagrassesdeteriorate under nutrient-rich, low-light conditions.
PB Inter Research
SN 0171-8630
YR 2013
FD 2013-11-20T00:00:00Z
LK http://hdl.handle.net/10498/16768
UL http://hdl.handle.net/10498/16768
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 13-nov-2026