INTRODUCTION Environment Agency - Abu Dhabi publishes this quarterly Marine Water Quality (MWQ) report to present the MWQ status during the previous three months based on the results of MWQ monitoring along the Abu Dhabi Emirate coast. The MWQ monitoring stations are distributed throughout the territorial waters of the Emirate. This report summarizes data on six MWQ parameters (eutrophic and microbial) for which thresholds have been recommended to protect marine biota and human health.
1
Each quarterly report present MWQ data for that quarter period, in addition, the 2nd and 4th quarter reports include Marine Water Quality Index (MWQI), which provides decision makers and the public with meaningful summaries of overall water quality status at different sites. A WQI is calculated for the following eutrophic parameters (Eutrophication Index): Dissolved Oxygen (DO); Chlorophyll-a; Nitrate; Ammonia; Phosphate; and for the following bacterial parameters (Microbial Index): Enterococci and Fecal Coliforms (FC). The Eutrophication Index provides information on parameters such as nutrients and dissolved oxygen, which largely result from human activities. High levels of nutrients in marine water can result in enhanced growth of aquatic plants, especially phytoplankton (micro algae). As a result, phytoplankton populations increase rapidly and the excess, unconsumed plant material can cause problems such as diminished water clarity and DO depletion in waters. Severe eutrophic conditions may also contribute to the formation of harmful algal blooms (HABs), which may include species that can cause foul odours, skin rashes from water contact, fish kills, and shellfish poisoning, and can disrupt the normal operation of desalination plants by blocking their seawater filtration systems. Increasing eutrophication and higher frequencies of harmful algal blooms have been observed in Abu Dhabi waters in recent years. This quarterly report presents data on the eutrophic parameters: DO, Chlorophyll-a, Nitrate, Ammonia, and Phosphate. EAD has been and will continue to be alert to microbial levels in order to control public health risks from recreational exposure to marine water. This report presents data on enterococci – the best indicator of sewage contamination of marine water.
DISSOLVED OXYGEN (DO)
MEAN DISSOLVED OXYGEN (DO) CONCENTRATIONS (mg/L) IN ABU DHABI EMIRATE WATER MARINE WATER QUALITY SAMPLING STATIONS 4.7 4.5
20
During the third quarter of 2015, dissolved oxygen concentrations in waters did not meet the minimum recommended threshold level (>4 mg/L) at 4 out of 20 stations(20%) for which there were data. There are not bottom water data available for stations 5 and 6 because these are point sources and the samples are taken directly from the source.
