More tests confirm effluents as cause of marine disaster

The analysis of seawater and dead fish samples collected from Mussafah Creek show strong indications that the recent marine disaster in the creek was caused by illegal discharge of industrial waste.

According to another report released by the Environmental Research and Wildlife Development Agency (Erwda), its experts repeated their examination of the samples to compare the results to determine if conditions observed on the first day persisted.

Abu Dhabi's prime environmental agency selected five sampling stations along the five-kilometre affected stretch of the creek. The Erwda team, headed by Dr Anbiah Rajan, Associate Scientist, Primary Productivity, and Francis Franklin, Senior Technician, Fisheries, visited the five stations with the objective of finding out the cause of mass deaths, to identify the fish species affected and the impact of the incident on the immediate and adjacent environment.

According to the team, the dead fish was dominated by one pelagic species belonging to the family of sardines, Nematolosa nasus. At least two other species were found in small quantities such as Leiognathus Bindus and Platycephalus Indicus.

"It is evident from the analysis that station three and four, closest to the sewage discharge pipeline, consistently had the lowest levels of dissolved oxygen and the highest level of nutrients (Nitrate, Nitrite, Silicate, Ammonia and Phosphate)," the report said.

The results in the areas further away from the discharge pipeline on the other hand, were closer to the normal situation and the station closest to the open sea had relatively high level of Oxygen and low nutrient level, according to the report, released by Erwda yesterday.

It is also significant that oxygen levels in all stations taken on the day after sewage discharge from the pipeline had stopped showing normal conditions. The microbiological analysis reported high levels of total coliform (10CFU/ 100ml), faecal Coliform (10CFU/ 100ml) and faecal streptococcus (200CFU/100ml) for station three. The levels for these parameters in the other stations, however, were low.

The investigations also indicated that there was an algal bloom formation. The report concluded that the results suggest the fish-kill was caused by localised eutrophication of the area, most probably due to the discharges from the pipe-line. The eutrophic condition means rich in nutrients, which causes density in water that causes decline in oxygen in the water.