Anthropogenic Impact on Benthic Foraminifera, Abu-Qir Bay, Alexandria, Egypt

Abstract

The present study examines the foraminiferal distribution in recent bottom sediments of Abu-Qir Bay located along the Mediterranean coast of Alexandria, Egypt. Abu-Qir Bay receives substantial amounts of heavy metals from the surrounding industrial area, as well as agricultural and domestic effluents, which makes it one of the most polluted areas along the Mediterranean coast. Information provided by the benthic foraminiferal associations was integrated with geochemical, sedimentological, and water data to characterize the environments. The benthic foraminifera are recognized as potential indicators of pollution in coastal marine environments. Surface sediment samples were collected in two seasons (May and November) from nine sites. Cluster analysis and Canonical Correspondances Analysis reveal a distinct boundary that separates two areas; the more-polluted stations nearshore, and the less-polluted stations offshore The first area is characterized by sediment with high silt and clay content and rich in total organic carbon, and bottom water with relatively high temperatures, but low in dissolved oxygen, salinity, transparency, and pH. Its foraminiferal fauna is dominated by Ammonia tepida, Quinqueloculina lata, and Porosononion spp., which are species considered as pollution opportunists. The second area is characterized by coarser sediment overlain by bottom waters high in dissolved oxygen, and transparent, saline, cold water, and is dominated mainly by Quinqueloculina vulgaris, Elphidium spp., Asterigerinata mamilla, Rosalina macropora, Ammonia beccarii, Triloculina trigonula, Peneroplis pertusus, and Quinqueloculina spp. Heavy-metal pollutants have a deleterious effect on benthic foraminifera that results in reduced population diversity, increased dominance, and deformed tests.

Developing Foram-AMBI for biomonitoring in the Mediterranean: Species assignments to ecological categories

“…Conversely, at polluted sites, organic supplies are usually accompanied by a more or less wide range of toxic chemical compounds, and the faunas potentially show a response to a multiple stressor context. In many cases of anthropogenic pollution there is a positive correlation between TOC and the concentrations of chemical pollutants (e.g., Romano et al, 2009Romano et al, , 2013 and by Elshanawany et al, 2011), and TOC values can be used as an integrative descriptor of pollution. However, in some studies, the correlation between TOC and other pollutants is much less evident (e.g., Samir and El-Din, 2001), and TOC may not be a good descriptor for ecosystem stress.…”

“…In some studies, only very few representatives of Groups III, IV and V were observed. This concerned the studies of Samir and El-Din (2001), Hyams-Kaphzan et al (2008), Romano et al (2009) and Elshanawany et al (2011). These studies apparently did not include heavily organic matter enriched sites.…”

Assessment of the impacts of trace metals on benthic foraminifera in surface sediments from the northwestern Taiwan Strait

“…Quinqueloculina lata and Quinqueloculina stelligera dominated an area in Naples that was heavily polluted with trace metals . However, other studies assert that the Quinqueloculina genus prefers well-oxygenated environments and is sensitive to heavy metal pollution (e.g., Ferraro et al (2006), Elshanawany et al (2011), Martins et al (2013)). …”

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“…Tekanan antropogenik ini menjadi semakin besar dengan meningkatnya aktivitas manusia di sepanjang pesisir dan atau di sepanjang aliran sungai. Alve (1995), Elshanawany et al (2011), dan Jayaraju et al (2008 menemukan rendahnya keragaman jenis dan adanya cangkang abnormal pada foraminifera bentik di perairan marjinal yang mendapatkan tekanan ekologis akibat aliran bahan antropogenik.…”