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Dynamics of the relative nitrogen and phosphorus concentrations in a reservoir situated in a semi-arid zone (Sahela, Morocco)

Abstract

Fluctuations in total nitrogen and phosphorus concentrations and in the N/P ratio (i.e. in terms of mass) were measured at the entry and exit of the Sahela Reservoir (Morocco) throughout an annual cycle. Particulate N and P concentrations in sedimenting particles in the reservoir itself were also measured. The results obtained showed that the spring floods were a major source of N and P inputs, this being especially pronounced for phosphorus that was present mainly in particulate form. In all the compartments of the reservoir analysed, the N/P ratios were high (means between 81 and 314), especially in summer (the only season when the reservoir was emptied) when the supply of P was apparently limited by the drought. However, the values of this ratio in the sedimenting particles remained lower (mean = 21), at levels characteristic of natural communities. This implies that the reservoir's biological communities preferentially store phosphorus, no doubt to maximise their activity in an environment where a large proportion of this element is not bioavailable. Furthermore, it appeared that the quantity of particulate N and P sequestrated by the sediments and the total quantities of N and P leaving the reservoir were greater than the inputs of these nutrients, underlining the importance of lateral and internal nutrient supplies. One spot measurement, made in a single month, showed that nutrient release activity from the sediments was in fact quite considerable.

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References

  1. Abouzaid H, Foutlane A (1986) L'eutrophisation de quelques lacs réservoirs au Maroc. Revue Marocaine de génie civil et des travaux Publics 9:4–58

  2. Alaoui Mhamdi B (2001) Eutrophisation du réservoir Sahela: Etude des bilans biogéochimiques de l'azote et du phosphore. Thèse de doctorat national, Université Sidi MohammedBenAbdellah, Fès

  3. Alaoui Mhamdi M, Aleya L, Restituito F, Devaux J (1993) Optimisation méthodologique de l'utilisation des chambres benthiques pour l'estimation des flux des divers éléments chimiques à l'interface eau-sédiment des écosystèmes limniques. Cahiers de l'INRA 30:47–54

  4. Alaoui Mhamdi M, Aleya L, Devaux J (1994) Phosphorus exchanges between sediment and water in trophically different reservoirs. Wat Res 28:1971–1980

  5. Alaoui Mhamdi M, Aleya L, Bahhou J (1996) Nitrogen compounds and phosphate of the Driss I Reservoir (Morocco): input, output and sedimentation. Hydrobiologia 335:75–82

  6. Arbuckle KE, Downing JA (2001) The influence of wathershed land use lake on N: P in a predominantly agricultural landscape. Lmnol Oceanogr 46:970–975

  7. Bahhou J (2001) Dynamique et métabolisme des populations phytoplanctoniques du réservoir Driss 1er. Thèse de doctorat d'état. Université Université Sidi MohammedBenAbdellah, Fès

  8. Bouhaddioui A (1997) Bilan biogéochimique de l'azote et du phosphore et dynamique des populations phytoplanctoniques de la retenue de barrage Allal El Fassi. Thèse 3ème cycle. Université F.S.T. Sais, Fès

  9. Billen G, and Garnier J (2000) Nitrogen transfert trought the seine drainage network: a budget based on the application of the “rivers trahler model”. Hydrobiologia 410:139–150

  10. Billen G, Lancelot C, Meybeck M (1991) N, P, and Si retention along the aquatic continuum from land to ocean, p 19–44. In R.F.C. Matoura J. M, and R. Wollast [eds], Ocean Margin process in global change, Wiley, NY

  11. Carpenter SR, Caraco NF, Correll DL, Howarth RW, Sharpley AN, Smith VH (1998) Non-point pollution of surface waters with phosphorus and nitrogen. Ecol Appl 8:559–568

  12. Cherifi O, Loudiki M (1999) Flood transport of dissolved and suspended matter in the El Abid river bassin (Morocco). Hydrobiologia 410:287–294

  13. Downing JA, Osenberg CW, Sarnelle O (1999) Meta-analysis of marine nutrient-enrichment experiments : variation in the magnitude of nutrient limitations. Ecology 80:1157–1167

  14. Gächter R, Meyer JS, Mares A (1988) Contribution of bacteria to release and fixation of phosphorus in lake sediments. Limnol. Oceanogr 33:1542–1558

  15. Hall P (1984) Chemical fluxes at the sediment-seawater interface: In situ investigations with benthic chambers. Ph. D. thesis. Kemihuset, Chalmers, Tekniska, Högskola göteborg. 138 p

  16. Hecky RE, Kilham (1988) Nitrient limitation of phytoplankton in freshwater and marine environments: A review of recent evidence on the effects of enrichments. Limnol. Oceanogr 33:796–822

  17. Hesselein RH (1980) In situ measurements of pore water diffusion coefficients using tritiated water. Can J Fish Aquat Sci 137:545–551

  18. Howarth RW, Jensen HS, Marino R, Postma H (1995) Transport to and processing of P in near-shore and oceanic waters, p. 232–346. In Thiessen H (ed), Phosphorus in the global environment. Transfers cycles and management, Wiley, NY

  19. Krovang B, Aertbjerg G, Grant R, Kristensen R, Hovmand M, Kirkegaard J (1993) Nationwide monitoring of nutrients and their ecological effects: state of the Danish aquatic environment. Ambio. 22:176–187

  20. Knauer GA, Martin JH, Bruland KW (1979) Fluxes of particulate carbon and phosphorus in the upper water column of the northeast Pacific. Deep Sea Res 26:97–108

  21. Landner L, Wahlgren U (1986) L'eutrophisation des lacs et réservoirs en climat chaud. O. M. S., P. N. U. D., Paris, 170p

  22. Lathrop RC (1988) Evaluation of whole-lake nitrogen fertilization for controlling blue-green algal blooms in a hypertrophic lake. Can J Fish Aquat Sci 45:2061–2075

  23. Loehr RC (1974) Characteristics and comparative magnitude of non-point sources. J Water Pollut Control Fed 46:1849–1872

  24. McCauley E, Doming JA (1991) Different effects of phosphorus and nitrogen on chlorophyll concentration in oligotrophic and eutrophic lakes. Can J Fish Aquat Sci 48:2552–2553

  25. McQueen DJ, Post JR, Mills EL (1986) Trophic relationships in freshwater pelagic ecosystems. Can J Fish Aquat Sc 43:1571–1581

  26. Molot LA, Dillon PJ (1991) Nitrogen/phosphorus ratios and prediction of chlorophyll in phosphorus-limited lakes in central Ontario. Can J Fish Aquat Sci 48:140–145

  27. Murphy J, Riley JP (1962) A modified single solution method for the determination of phosphate in natural waters. Annal Chim Acta 27:31–36

  28. Nalewajko C, Lean DRS (1980) The physiological ecology of phytoplankton. Nutrients dynamics. Phosphorus. In: The physiological ecology plankton, Morris (ed.) Blackwell Sci. Publ., London, p 235–258

  29. Philippe L (1989) Bilans biogeochimiques du fer et du phosphore dans un écosystème eutrophe: le lac Aydat (Puy de Dôme). Thesis, University of Paris VI, Paris

  30. Prepas E, Trew DO (1983) Evaluation of the phosphorus-chlorophyll relationship for lakes off the Precambrian shield in western Canada. Can J Fish Aquat Sc 40:27–35

  31. Rodier J (1984) Analyse de l'eau. Edition Dunod, Paris, 1135 pp

  32. Schindler DW, Kalff J, Welch HE, Kning H, Brunskill GJ, Kritsch N (1974) Eutrophication in the high arctic-Meretta Lake, Cornwallis Island (75° in lat.). J Fish Res Board Can 31:647–662

  33. St-Hilaire A, Caissie D, El Jabi N, Morin G (1998) Evaluation de l'application d'une méthode statistique aux variations saisonnières des relations concentration-débit sur un petit cours d'eau. Rev Sci Eau 11:175–190

  34. Smith VH, Shapiro J (1981) Chlorophyll phosphorus relations in individual lakes. Their importance to lake restauration strategie. Envir Sci Technol 15:444–451

  35. Smith VH (1983) Low nitrogen to phosphorus ratios favour dominance by blue-green algae in lake phytoplankton. Science 221:669–671

  36. Smith VH, Bennett SJ (1999) Nitrogen: phosphorus supply ratios and phytoplankton community structure in lakes. Archiv Hydrobiol 146:37–53

  37. Squalli Houssaini T (1995) Etude de la qualité des eaux de la retenue du barrage Sahela, C.E.A, Université Sidi MohammedBenAbdellah, Fès

  38. Stocker JG, Northcote TG (1974) Recent limnological studies of Okanagan basin lakes and their contribution to comprehensive water resource planning. J Fish Res Bd Can 31:955–976

  39. Suttle CA, and Harrison PJ (1988) Ammonium and phosphate uptake rates, N:P supply ratios, and evidence for N and P limitation in some oligotrophic lakes. Limnol Oceanogr 33:186–202

  40. Tilman D, Kilham SS, Kilham P (1982) Phytoplankton community ecology: the role of limiting nutrients. Annu Rev Eco Syst 13:349–372

  41. EPA (U.S. Environmental Protection Agency) (1995) National water quality inventory: 1994 report to congress. EPA Publication 841p.

  42. Vollenweider RA (1968) Les bases scientifiques de l'eutrophisation des lacs et des eaux courantes sous l'aspect particulier du phosphore et de l'azote comme facteurs d'eutrophisation. O. C. D. E., Paris. 182 p

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Correspondence to T. Sime-Ngando.

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Mhamdi, B.A., Azzouzi, A., Mhamdi, M.A. et al. Dynamics of the relative nitrogen and phosphorus concentrations in a reservoir situated in a semi-arid zone (Sahela, Morocco). Water Resour Manage 21, 983–995 (2007). https://doi.org/10.1007/s11269-006-9068-5

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Keywords

  • Reservoirs
  • Nutrient dynamics
  • Nutrient flows
  • Nitrogen
  • Phosphorus
  • N/P ratio