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Environ Monit Assess (2010) 165:399406 DOI 10.1007/s10661-009-0955-0
Interseasonal hydrological characteristics and variabilities in surface water of tropical estuarine ecosystemswithin Niger Delta, Nigeria
Akan B. Williams Nsikak U. Benson
Received: 2 January 2008 / Accepted: 18 April 2009 / Published online: 14 May 2009 Springer Science + Business Media B.V. 2009
Abstract We present a seasonal and baseline survey of selected physicochemical parameters in epipelagic samples from Qua Iboe (QIB) and Cross River (CRV) estuaries in Niger Delta region of Nigeria. The parameters analysed were temperature, pH, salinity, turbidity, total suspended solids (TSS), dissolved oxygen (DO), biochemical oxygen demand (BOD), total organic carbon (TOC), total nitrogen, available phosphorus, Ca2+, Mg2+, Na+, K+ (exchangeable cations)
and SO24, Cl, NH+4 and NO3. The results showed that the physicochemical parameters exhibited spatiotemporally explicit variabilities. The mean levels of the parameters were higher during the wet season (JuneSeptember) except salinity, DO, Cl and NH+4 in CRV, whilst QIB recorded higher mean levels for temperature, pH, salinity, BOD, TOC, SO24, Cl and NH+4 during the dry season (NovemberFebruary). Signicant sea-
A. B. Williams N. U. Benson
Department of Chemistry, Covenant University, Canaan Land, P.M.B, 1023, Ota, Nigeria
N. U. Benson (B)
Department of Atmospheric and Oceanic Sciences, McKinley Ocean Biogeochemistry Research Group, University of Wisconsin, Madison, WI 53706, USA e-mail: [email protected]
sonal variability was recorded for salinity, DO, turbidity, TSS, SO24 and NH+4 levels in CRV and for turbidity, DO, BOD, TSS, TOC, available
P, Na, Cl and NO3 levels in QIB. This study conrmed that the degree of variability of the various physicochemical surface water quality indicators is dependent on the prevalent environmental estuarine factors.
Keywords Water chemistry Estuary Pollution
Niger Delta Physicochemical compositions
Introduction
The growing concern in recent times over the uncontrolled pollution of aquatic environments by anthropogenic substances especially from crude oil spills and industrial efuents has resulted in a number of studies designed to provide information on the distribution of naturally occurring physical, chemical and biological characteristics within these systems and to gain some understanding of possible environmental effects of increasing human-driven inputs. It is well known that the functioning of pristine aquatic ecosystems is increasingly being inuenced by human-mediated activities. A number of eld reports on the monitoring and assessment of rivers, creeks and stream...