Dead fish at Plymouth in June.

The Division of Infrastructure, Quarries and the Environment (DIQE) has concluded the investigation into fish kill in the village of Plymouth in June.

Fishermen in the area claimed the sewer system at the nearby Adventure Housing Estate as the cause.

Giving an update at the post-executive council news conference on Wednesday, secretary for the Division Kwesi Des Vignes said experts from the department of the Environment and the Division of Food Production and Fisheries walked the Courland River and all the tributaries collecting data.

He said necropsies were performed. He also debunked the Plymouth fishermen’s allegations that the poor-working sewer system at the Adventure Housing Estate was the cause.

“We have found that is not the case, as a matter of fact just to explain what happens with the Sewage Treatment Plants, the sewage goes to the treatment plant and it goes through a number of processes and then there is an emission from the plant.

“That emission, which is supposed to be water, it is supposed to meet certain quality and standards, as a matter of fact some companies boast that when their plants treat the water, you can then drink the water,” he said.

Des Vignes said the WASA Treatment Plant at Courland is part of their monitoring programme and additional recommendations were given for improvement of their treatment process.

He said prior to the fish kill the division had cleared the mouth of the river, which may have been a contributing factor. He said only two species of fish were affected.

“So it could have been that when the river mouth cleared, there were some rough seas and high tides that the salinity in that area of the river would have increased and that could have contributed to the fish kill.

“The other suggestion is that because of the heavy rains, that area has a lot more agriculture going on now, both livestock and fresh produce, so it could be that chemicals used tin agriculture could have contributed that,” he said.

Des Vignes said there were also low levels of dissolved oxygen in the water, but the situation is continuously being monitored.