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Abstract

The distribution of inorganic nutrient salts (ammonium, nitrite, nitrate, phosphate and silicate) and phytoplankton chlorophyll-a (Chl-a) were investigated in the Gulf of Aden and along the Arabian Sea coast, Yemen. Seventy two surface water samples were collected during cruises in August 2014 and January 2015. The sampled area extends from As Suqayyah in the west of the Gulf of Aden to Hawf in the east. The study showed that the average values of nutrient salts (μg/l) in waters collected in August 2014 and January 2015 were 0.83 and 0.60, 10.98 and 10.03, 16.41 and 14.73, 10.36 and 8.76, and 29.72 and 22.67 for ammonium, nitrite, nitrate, phosphate and silicate, respectively. The average values of Chl-a (mg/m3) in August 2014 and January 2015 were 0.26 and 0.21, respectively. The results showed that nitrate levels were very high but those of ammonium very low. This may reflect the oxidation of ammonia to nitrite and then nitrate, leading to a very favorable ratio of ammonia and nitrate values. The low levels of dissolved inorganic nitrogen (DIN)compounds, (ammonium, nitrite, and nitrate), phosphate, silicate and Chl-a indicated that the southern coast of Yemen is not in a eutrophic condition. The highest nutrient salt values were in the eastern part of the study area, and may have resulted from water originating from the Indian Ocean and upwelling. Statistical analysis to seek correlations between nutrient salts and Chl-a show very good to excellent correlation, which may be due toconstant coastal environment.

Keywords

Arabian Sea Gulf of Aden Nutrient salts Chlorophyll-a Yemen.

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References

  1. Ba-Sumaid, A.A. Effects of Masila oil Terminal on coastal Fauna M.Sc. Thesis, Dep. Biology, Fac. Sci, Sana’a University, 1997, 133p.
  2. Naval Oceanography Command Detachment. Climate study of the near coastal zone, Red Sea south and Gulf of Aden. U.S. Naval Oceanographic Command Detachment, Asheville, NC, 1982- USA.
  3. Howe, G.H., Reed, L.J., Ball, J.J., Fisher, G.E. and Lasso, W.G. Classification of world desert areas. Report 69-38ES, Earth Science laboratory, United States Army Natick Laborites, Natick, MA, 1968.
  4. Al-Shwafi, N.A and Ahmed, A.M. A Systematic Evolution of Selected Nutrient and Chlorophyll - A Along of Hadramout Coast, Yemen. Academic Notes, 2009, No. 9.
  5. Cederwall, H. and Elmgren, R. Biomass incase of Benthic macrofauna Demonstrates Eutrophication of the Baltic Sea. Ophelia Supplement, 1980, 1, 287-304.
  6. Rosenberg, R. Eutrophication the future Marine Coastal Nuisance. Marine Pollution Bulletin, 1985, 16, 227-231.
  7. Degobbis, D. Increase Eutrophication of the Northern Adriatic. Sea: Secona Act. Marine Pollution Bulletin, 1989, 20, 452-457.
  8. Ferreira, J.G., Andersen, J.H., Borja, A., Bricker, S.B., Camp, J., Cardoso da Silva, M., Garcés, E., Heiskanen, A.S., Humborg, C., Ignatiades, L., Lancelot, C., Menesguen, A., Tett, P., Hoepffner, N., Claussen, U. Marine Strategy Framework Directive e Task Group 5 Report Eutrophication. EUR 24338 EN Joint Research Centre. Office for Official Publications of the European Communities, Luxembourg, 2010, 49 p.
  9. Malagó, A., Bouraoui,F., Grizzetti, B., and Roo., A.D. Modelling nutrient fluxes into the Mediterranean Sea. Journal of Hydrology: Regional Studies, 2019, 22.
  10. Friligos, N. Nutrient Conditions in the Euboilkos Gulf (West Aegean). Marine Pollution Bulletin, 1985, 16, 435-439.
  11. Zoffmann, C.F. Rodriguez-Valera, M. Perez_fillol, F. Ruia-Bevia, M. Torreblance and F. Colom, Microbial and Nutrient Pollution Along the Coasts of Alicante, Spain Marine Pollution Bulletin, 1989, 20, 74-81.
  12. Hassan, E.S. Banat, I.M., El-Shahawi, S. and Abu-Hilal, A.H. Asystematic Evolution of Selected Nutrients, Heavy Metals and Microbial pollution Along the east Coast of the United Arab Emirate University Journal of Faculty of Science., UAE University, 1995, 17, 203-226.
  13. Riley, J.P. Nutrient Chemicals (including those derived detergents and agricultural chemicals). In: A Guide to Marine Pollution. (Goldberg, E.D., ed). Gordon and Beach Science Publishers, New-York, London, Paris, 1978.
  14. Rahav, E., Raveh, O., Hazan, O., Gordon, N., Kress, N., Silverman, J., Herut, B. Impact of nutrient enrichment on productivity of coastal water along the SE Mediterranean shore - a bioassay approach. Marine Pollution Bulletin, 2018, 127, 559-567.
  15. Raveh, O., David, N., Rilov, G., Rahav, E. The temporal dynamics of coastal phytoplankton and bacterioplankton in the eastern Mediterranean Sea. PLOS One 10, e0140690, 2015.
  16. McDonald, R.W., McLaughlin, F.A. The effect of storage by freezing of dissolved inorganic phosphate, nitrate and reactive silicate for samples from coastal and estuarine waters. Water Respiratory., 1982, 16:95-104.
  17. Strickland, J. and Parsons, T. A practical handbook of sea water analysis. Bulletin of the Fisheries Research Board of Canada, 1972, 167, 310p.
  18. Alsayed, A. and Ghaddaf, M. Upwelling and fish mortality, in the northern Gulf of Aden, Indian Journal of Marine Science, 1993, 22, 305-307.
  19. UNDP/GEF. Biodiversity conservation and sustainable development programme, Socotra Archipelago, Republic of Yemen. Mac Alister Elliott and partners Ltd. United Kingdom, 1996.
  20. Gittings J.A., Raitsos D.E., Racault M., Brewin R.J., Pradhan Y., Sathyendranath S., and Platt T. Seasonal phytoplankton blooms in the Gulf of Aden revealed by remote sensing, Remote Sensing of Environment, 2017, 189, 56-66.
  21. Alkawri, A. and Gamoyo, M. Remote sensing of phytoplankton distribution in the Red Sea and Gulf of Aden, Acta Oceanologica Sinica, 2014, 33(9), 93-99.
  22. Kandil, M.M. Hydrological and chemical studies on the Red Sea waters infront of Hurgada. M.Sc. Thesis, Alex. University, 1982.
  23. Fahmy, M.A., Beltagi, A.I. and Abbas, M.M. Nutrient salts and Chlorophyll-a in the Egyptian Mediterranean coastal waters. MEDCAST 99- EMECS99 Joint conferences, Land-Ocean. Interactions: Managing costal Ecosystems, 9-13 November, Antalya, Turkey, 1999.
  24. Boze, R. and Tomczak, M. Upwelling ecosystems. Springer Verlag, Berlin.,1978, 303 p.
  25. Anglès, S., Jordi, A., Henrichs, D.W. and Campbell, L. Influence of coastal upwelling and river discharge on the phytoplankton community composition in the northwestern Gulf of Mexico. Progress in Oceanography, 2019, 173, 26-36.
  26. Carlson, R. A trophic state index for lakes. Limnology and Oceanography,1977,22(2), 361-369.
  27. UNESCO, 1990. Review of potentially harmful substances. Nutrients, Reports and Studies, No.34. 40p.
  28. Kucuksezgin, F., Balci, A., Kontas, A., and Alta Y, O. Distribution of nutrients and chlorophyll-a in the Aegean Sea, Oceanologica Acta.,1995, 18, 343-352.
  29. Khomayis, H.S. The Annual Cycle of Nutrient Salts and Chlorophyll-a in the Coastal Waters of Jeddah, Red Sea. Journal of King Abdulaziz University: Marine Science., 2002, 13,135-141.
  30. Ignatiades, L., Karydis, M., Vounatsou, P. A possible method for evaluating oligotrophy and eutrophication based on nutrient concentration scales. Marine Pollution Bulletin, 1992, 24(5), 238-43.