MEPS 365:67-75 (2008)  -  DOI: https://doi.org/10.3354/meps07512

Increased vulnerability of Zostera noltii to stress caused by low light and elevated ammonium levels under phosphate deficiency

Fernando G. Brun1,3,*, Irene Olivé1, Erik-jan Malta2, Juan J. Vergara1, Ignacio Hernández1, J. Lucas Pérez-Lloréns1

1Departamento de Biología, Area de Ecología, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz,
11510 Puerto Real, Cádiz, Spain
2ALGAE—Marine Plant Ecology Research Group, CCMAR, Universidade do Algarve, Gambelas, 8005-139 Faro, Portugal
3Present address: Netherlands Institute of Ecology (NIOO-KNAW), Centre for Estuarine and Marine Ecology, Korringaweg 7, 4401 NT Yerseke, The Netherlands

ABSTRACT: The effects of light and ammonium levels on net production, fluorescence parameters and non-structural carbohydrates of the seagrass Zostera noltii under different phosphate conditions were studied. A fully factorial design was used with light (low/high levels), ammonium supply and phosphate preculture conditions of the plants as the experimental variables. Both ammonium supply and low light caused negative and synergistic effects on net production, while ammonium toxicity was more severe at high light levels; in this case, it was independent of the non-structural carbohydrate (sucrose and starch) content. Preculturing of plant with added phosphate alleviated the ammonium toxicity, and also attenuated the negative production balance of plants grown at low light levels. The results indicated that phosphate preculture ameliorated the plant’s short-term response against the assayed stressors (low light, high ammonium) significantly. An overall consumption of non-structural carbohydrates in response to environmental stressors was recorded throughout the experiment, indicating the importance of carbon and phosphorus reserves to cope with adverse conditions. In addition, phosphate deficiency increased the vulnerability of plants, which could have negative ecological consequences for seagrass species thriving under phosphate deficiency conditions, or in developing seagrass transplantation programs.


KEY WORDS: Ammonium toxicity · Carbohydrates · Eutrophication · Fluorescence · Net production · Phosphate limitation · Seagrass


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Cite this article as: Brun FG, Olivé I, Malta E, Vergara JJ, Hernández I, Pérez-Lloréns JL (2008) Increased vulnerability of Zostera noltii to stress caused by low light and elevated ammonium levels under phosphate deficiency. Mar Ecol Prog Ser 365:67-75. https://doi.org/10.3354/meps07512

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