نقش درختان حرا در کاهش آلودگی فلزات سنگین رسوبات خور بساتین

نوع مقاله: علمی- پژوهشی

نویسندگان

1 پژوهشگر، گروه مهندسی رودخانه و سواحل، پژوهشکده حفاظت خاک و آبخیزداری کشور، سازمان تحقیقات، آموزش و ترویج کشاورزی

2 دانشیار، گروه اکولوژی، دانشکده علوم و فنون دریایی، دانشگاه آزاد اسلامی واحد تهران شمال

3 استادیار پژوهش، گروه مهندسی رودخانه و سواحل، پژوهشکده حفاظت خاک و آبخیزداری کشور، سازمان تحقیقات، آموزش و ترویج کشاورزی

4 استادیار، سازمان زمین‌شناسی کشور

5 استادیار پژوهش، پژوهشکده اکولوژی خلیج فارس و دریای عمان، سازمان تحقیقات، آموزش و ترویج کشاورزی

چکیده

خور بساتین در سواحل شمالی خلیج فارس و شرق استان بوشهر از یک‌سو به خلیج نای‌بند و از سوی دیگر به رودخانه گاوبندی منتهی می‌شود. خور بساتین ازنظر دارا بودن شرایط ویژه اکولوژیکی، یکی از زیستگاه‌های جنگل‌های حرا در سواحل شمالی خلیج فارس به‌شمار می‌رود، اما در سال‌های اخیر جایگاه تمرکز انواع آلاینده‌های ‌محیط زیستی شده است. آشکارسازی نقش تعدیل‌کننده جنگل‌های حرا در کاهش آلودگی و شناخت وضعیت تمرکز عناصر فلزی و شبه‌فلزی و تطابق آنها با رویدادهای محیطی در خور بساتین از اهداف پژوهش پیش‌رو بود. روش تحقیق به‌گونه‌ای طراحی شد که نمونه‌برداری جامعی با توجه به وسعت خور بساتین از رسوبات سطحی و عمقی دست‌‌نخورده انجام شود و غلظت 50 عنصر فلزی، شبه‌فلزی و عناصر نفت- پیوند تعیین شود. 120 نمونه رسوب پس از آماده‌سازی، توسط دستگاه ICP-OES  تجزیه و تحلیل شدند. همچنین در تجزیه و تحلیل آماری از نرم‌افزار ماکرو XL Stat Pro 2015  به‌منظور بررسی ارتباط بین عناصر استفاده شد. نتایج پژوهش پیش‌رو نشان داد که با تغییر ریخت‌شناسی دهانه خور بساتین از سال 1379 و محدود شدن چرخه هیدرولیکی جریان‌های جزرومدی، نرخ رسوب‌گذاری در خور بساتین به‌اندازه‌ای افزایش یافته است که باعث خشک شدن درختان حرا شده‌ است. این فرآیند نقش مستقیمی در غنی‌شدن فلزات سنگین در خور بساتین و عدم پالایش آنها توسط گیاهان داشته است. نتایج نشان داد که نرخ متوسط رسوب‌گذاری در خور بساتین بین 1/8 تا دو سانتی‌متر در سال در تغییر بوده است.

کلیدواژه‌ها


عنوان مقاله [English]

The role of gray mangroves in reducing pollution of heavy metals in Basatin Estuaries sediments

نویسندگان [English]

  • Hamid Davoodi 1
  • Hoseyn Negarestan 2
  • Mohammad Reza Gharibreza 3
  • Razieh Lak 4
  • Mohammad Raza Mortazavi 5
1 Research Expert, Department of River and Coastal Engineering, Soil Conservation and Watershed Management Research Institute (AREOO)
2 Associate Prof., Department of Ecology, School of Marine Science and Technology, Islamic Azad University, North Tehran Branch
3 Assistant Prof., Department of River and Coastal Engineering, Soil Conservation and Watershed Management Research Institute (AREOO)
4 Assistant Prof., Geological Survay and Mineral Exploration Organization of Iran
5 Assistnt Prof., Persian Gulf and Oman Sea Ecology Research Center (AREOO)
چکیده [English]

Basatin Estuary is located in the north of the Persian Gulf and in the east of Boushehr province, which is opening into the Nayband Bay and is connected to the Gavbandi River. This estuary is considered as one of mangroves forests in the northern shores of the Persian Gulf because of its spectacular ecological condition. On the other hand, Basatin estuary is setting for enrichment of several kinds of pollutions during the recent years. Therefore, this research aimed at 1) highlighting the role of the mangrove forest in mitigation and reducing concentration of pollutions, 2) estimating the concentration of metallic and metalloid elements, in particular oil bonded and terrestrial bonded in surface and in the sediment columns of Basatin Estuary, and 3) identifying key horizons in the column sediments and their compatibility with the environment and man-made events. Therefore, a comprehensive sampling of the sedimentary faces and chemical analysis of wide range of elements (50 elements) were implemented. Totally 120 sediment samples were recorded and were analyzed using ICP-OES devices. In addition, statistical analysis was carried out to reveal relationships between similarity or dissimilarity elements. The results approved the research hypothesis, and e.g. showed that changing in the estuary mouth in 1991 has resulted in limitation of hydraulic circulation of tidal currents and caused a severe increase in sediment accumulation, followed by covering aerial roots by sediments and finally drying of mangrove trees. This process has a direct role in the enrichment of heavy metals in the environment. Furthermore, the uppermost layer of sediment column (0-25 cm) has experienced moderate to high degrees of pollution by petrochemical industries. This layer was significantly enriched by Zr, V, Ti, S, P, Ni, Mn, Li, Cr, Co, Ce, Cd, Bi, Ba, as elements. Finally, time correlation of key horizons and environmental events showed that the average rate of sedimentation in the estuary Basatin fluctuated between 1.8 and 2 cm per year.

کلیدواژه‌ها [English]

  • Biological filtration
  • heavy metals
  • horizonalkey
  • mangrove forests
  • Sedimentation rate

 

 

 

 

 

- Abu El-Regal, M.A. and Ibrahim, N., 2014. Role of mangroves as a nursery ground for juvenile reef fishes in the southern Egyptian Red Sea. The Egyptian Journal of Aquatic Research, 40(1): 71-78.

- Agormoorthy, G., Chen, F.A. and Hsu, J.M., 2008. Threat of heavy metal pollution in halophytic and mangrove plants of Tamil Nadu, India. Environmental Pollution, 155: 320-326.

- Alongi, D.M., Saskumar, A. and Chong, V., 2004. Sediment accumulation and organic material flux in a managed mangrove ecosystem: estimates of land-ocean-atmosphere exchange in peninsular Malaysia. Marine Geology, 208: 383-402.

- Andreetta, A., Fusi, M. and Cameldi, I., 2014. Mangrove carbon sink: Do burrowing crabs contribute to sediment carbon storage? Evidence from a Kenyan mangrove system. Journal of Sea Research, 85: 524-533.

- Anonymous, 2007. Evaluation of Nayband National Park, Booshehr. Published by Lar Consulting Engeeneers Company, Booshehr Province (In Persian).

- Ashraf, M.A., Sarfraz, M., Naureen, R. and Gharibreza, M., 2015. Environmental Impact of Metalic Elements. Springer, Singapore, 434p.

- Danehkar, A., Mashinchian, A., 2004. Selection of Reforestation Practice for Mangrove Forests of Iran Consequent to the Persian Gulf War. Directorate of Environmental Protection of Iran, Tehran, 101p.

- Chaudhuri, P., Nath, B. and Birch, G., 2014. Accumulation of trace metals in grey mangrove Avicennia marina fine nutritive roots: The role of rhizosphere processes. Marine Pollution Bulletin, 79: 248-292.

- Goudie, A., 1993. Human influnce in geomorphology. Geomorphology, 7: 37-59.

- Kingston, H.M. and Jassie, L.B., 1988. Introduction to Microwave Sample Prepration: Theory and Practice. American Chemical Society Press, Washigton, 263p.

- Lindsey, D.H., Mair, J.M. and Guzman, H.M., 2005. An assessment of metal contamination in mangrove sediments and leaves from Punta Mala Bay Pacific Panama. Marine Pollution Bulletin, 50: 547-552.

- Machado, W., Moscatelli, M., Rezende, L. and Laderda, L., 2002. Mercury, zinc, and copper accumulation in mangrove sediments surrounding a large landfill in southeast Brazil. Environmental Pollution, 120: 455-461.

- Meng-guo, L., 2010. The effect of reclamation in areas between islands in a complex tidal estuary on the hydrodynamic sediment environment. Journal of Hydrodynamics, 22(3): 338-350.

- Phung Ha, T.T., Dijk, H.V. and Visser, L., 2014. Impacts of changes in mangrove forest management practices on forest accessibility and livelihood: A case study in mangrove-shrimp farming system in Ca Mau Province, Mekong Delta, Vietnam. Land Use Policy, 36: 89-101.

- Prasad, B.K. and Ramanathan, A., 2009. Organic matter characterization in a tropical estuarine-mangrove ecosystem of India: Preliminary assessment by using stable isotopes and lignin phenols. Estuarinem Coatal and Shelf Science, 84: 617-624.

- Radtke, D.B., 2005. Bottom- Material Samples. Published by U.S. Department of the Interior. USGS, USA, 60p.

- UNEP, 2000. Overview on Land Based Sources and Activities Effecting the Marine Environment in the ROPME Sea Area. Regional Seas Reports and Studies, United Nations Environment Programme.

- Santin, C., De la Rosa, J.M., Knicker, H. and Gonzalez-Vila, F.J., 2009. Effects of reclamation and regeneration processes on organic matter from estuarine soils and sediments. Organic Geochemistry, 40(9): 931-941.

- Tampanya, U., Vermaat, J.E. and Terrados, J., 2002. The effect of increasing sediment accretion on the seedlings of three common Thai mangrove species. Aquatic Botany, 74: 315-325.

- Vaselali, A. and Azarmsa, S., 2009. Analysis of breakwater construction effects on sedimentation pattern. Journal of Applied Sciences, 19(9): 3522-3530.