Water transparency and health of coastal salt marshes: simple enclosure experiments on nutrient dynamics
Version of Record online: 24 JUL 2001
Copyright © 2001 John Wiley & Sons, Ltd.
Aquatic Conservation: Marine and Freshwater Ecosystems
Special Issue: Ecological Research and Conservation of Coastal Ecosystems
Volume 11, Issue 4, pages 273–279, July/August 2001
How to Cite
Basset, A., Carlucci, D., Fiocca, A. and Vignes, F. (2001), Water transparency and health of coastal salt marshes: simple enclosure experiments on nutrient dynamics. Aquatic Conserv: Mar. Freshw. Ecosyst., 11: 273–279. doi: 10.1002/aqc.455
- Issue online: 24 JUL 2001
- Version of Record online: 24 JUL 2001
- Manuscript Accepted: 27 JAN 2001
- Manuscript Received: 11 JUL 2000
- Ministero dell'Ambiente/Provincia di Lecce — project ‘Elaborazione del Master Plan per l'area degli Alimini (LE)’
- MURST, COFIN'99
- EEC. Grant Number: ENV4-CT97-0584
- enclosure experiments;
- Lake Alimini Grande;
- nutrient dynamics;
- phosphorus absorption processes;
- salt marsh ecosystem health;
1. In many coastal salt marshes, water transparency is decreased by the resuspension of sediments. We analyse the influence of suspended not-photosynthetic matter on the regulation of phosphorus (P) dynamics in the water column, compared with the role of phytoplankton and sediments.
2. Field surveys and manipulative experiments of P enrichment in light and dark enclosures, open and closed at their bottom, were performed in the brackish Lake Alimini Grande (Otranto, LE, Italy).
3. Water transparency in Alimini Grande was inversely related to seston organic mass, 98.8% of which was composed of dead organic matter and heterotrophic organisms.
4. P enrichment experiments showed an increase of the phytoplankton biomass with time from the beginning of the manipulation (4.9 times) in the light enclosures, but also an exponential decrease of P concentration in all the enclosures, even in the dark one closed at the bottom.
5. The rate of P removal from the water column was not significantly affected by phytoplankton activity, even though P concentration was always lower in light than in dark enclosures, or by the activity of sediments.
6. Dead suspended organic matter with associated micro-organisms seemed to remove nutrients very efficiently from the water column in Lake Alimini Grande, contributing significantly to control the potential risk of lake eutrophication. Copyright © 2001 John Wiley & Sons, Ltd.