National Status and Trends Bioeffects Program: field methods

Environmental quality indicators provide resource managers with information useful to assess coastal condition and scientifically defensible decisions. Since 1984, the National Oceanic and Atmospheric Administration (NOAA), through its National Status and Trends (NS&T) Program, has provided environmental monitoring data on chemical, physical, and biological indicators of coastal environments. The program has two major monitoring components to meet its goals. The Bioeffects Assessments Program evaluates the health of bays, estuaries, and the coastal zone around the nation using the Sediment Quality Triad technique that includes measuring sediment contaminant concentrations, sediment toxicity and benthic community structure. The Mussel Watch Program is responsible for temporal coastal monitoring of contaminant concentrations by quantifying chemicals in bivalve mollusks. The NS&T Program is committed to providing the highest quality data to meet its statutory and scientific responsibilities. Data, metadata and information products are managed within the guidance protocols and standards set forth by NOAA’s Integrated Ocean Observing System (IOOS) and the National Monitoring Network, as recommended by the 2004 Ocean Action Plan. Thus, to meet these data requirements, quality assurance protocols have been an integral part of the NS&T Program since its inception. Documentation of sampling and analytical methods is an essential part of quality assurance practices. A step-by–step summary of the Bioeffects Program’s field standard operation procedures (SOP) are presented in this manual.

Assessment of some physico-chemical parameters of River Ogun (Abeokuta, Ogun State, southwestern Nigeria) in comparison with national and international standards

This study assessed the physico-chemical quality of River Ogun, Abeokuta, Ogun state, Southwestern Nigeria. Four locations were chosen spatially along the water course to reflect a consideration of all possible human activities that are capable of changing the quality of river water. The water samples were collected monthly for seven consecutive months (December 2011 – June 2012) at the four sampling stations. pH, air temperature (℃), water temperature (℃), conductivity (µs/cm) and total dissolved solids (mg/L) were conducted in-situ with the use of HANNA Combo pH and EC multi meter Hi 98129 and Mercury-in-glass thermometer while dissolved oxygen (mg/L), nitrate (mg/L), phosphate (mg/L), alkalinity (mg/L) and hardness (mg/L) were determined ex-situ using standard methods. Results showed that dissolved oxygen, hydrogen ion concentration, total hardness and nitrate were above the maximum permissible limit of National Administration for Food, Drugs and Control (NAFDAC), Standard Organization of Nigeria (SON), Federal Environmental Protection Agency (FEPA), United States Environmental Protection Agency (USEPA), European Union (EU) and World Health Organization (WHO) for drinking water during certain months of the study period. Results also showed that water temperature and conductivity were within the permissible limits of all the standards excluding FEPA. However, total dissolved solids and alkalinity were within the permissible limits of all the standards. Adejuwon and Adelakun, (2012) also reported similar findings on Rivers Lala, Yobo and Agodo in Ewekoro local government area of Ogun state, Nigeria. Since most of the parameters measured were above the maximum permissible limits of the national and international standards, it can be concluded that the water is unfit for domestic uses, drinking and aquacultural purposes and therefore needs to be treated if it is to be used at all. The low dissolved oxygen values for the first four months was too low i.e. < 5 mg/L. This is most likely as a result of the amount of effluents discharged into the river. To prevent mass extinction of aquatic organisms due to anoxic conditions, proper regulations should be implemented to reduce the organic load the river receives.