An investigation is underway after hundreds of dead fish have been seen in the River Foss in York.
They are being carried downstream, creating an unpleasant smell of rotting flesh by the banks of the river.
The fish are floating on the surface of the river and can be seen in the city centre and next to Huntington Road.
Environmentalists have expressed fears that the deaths are linked to a possible pollution spill at the Foss Basin earlier in the week.
Mike Gray of the River Foss Society told YorkMix there were reports of foam on the surface of the water at the Foss Basin on Tuesday afternoon.
“At that stage we were not sure whether it was something natural or some form of pollution washed down by the heavy rain, but a report was made to the Environment Agency hotline,” he said.
“First thing Wednesday some photos arrived showing surface discoloration and dead fish floating on the river in the area around Sainsbury’s.
“Again it was reported to the EA as this is a category 1/2 incident and should be actionable.”
More reports of dead fish sightings came in over the last 48 hours, some as far up as the Sustrans bridge across the river and Huntington Road.
The society has taken a water sample from the Foss Basin in case it was required by the Environment Agency.
“The water was clear and clean looking in Huntington and New Earswick, so the problem seems to be lower down, though there was a report of dead fish in around Haxby, but nothing further came of this,” Mike said.
“It seems likely the two incidents are connected, and we are waiting for some accurate and hopefully timely feedback from either the Environment Agency or Yorkshire Water.”
Low oxygen theory
An Environment Agency spokesperson said: “We continue to investigate a number of fish deaths and fish in distress incidents across the country, including in Yorkshire.
“We believe that many of the problems we are seeing are as a result of low dissolved oxygen due to a combination of the high temperatures we have experienced recently, and the low atmospheric pressure caused by the thunderstorms.
“However, our officers are investigating at multiple locations to rule out any other causes such as pollution.
This Saturday, the River Foss Society is hosting an event with St Nicks to celebrate the Foss and promote the green corridors initiative.
There will be stall holders and activities, including pond dipping and scything.
- Willowbank Green, New Earswick
- Saturday, 24 June
- More here
“It is important that members of the public who spot fish in distress report it to our 24/7 incident hotline 0800 80 70 60 so that our officers can investigate.”
Mike said at this stage, the incident “seems to be less severe than the previous events some two or three years ago caused by a burst sewage pipes upstream around Earswick and West Nooks, but as fish stocks are thought to be lower now than then, that may not be correct.
“It does seem likely that the cause is lower down the river, towards the city, so it will hopefully affect less of the river.”
The society wants the water to be tested as soon as possible, with preliminary findings published “quickly and openly”.
“We are looking for facts at this stage rather than finger pointing. Once we know what the pollution is, it may be possible to locate its source.
“The River Foss Society has started to sample the macroinvertebrates living in and on the riverbed as a way of judging the river’s long term health.
“But as this is only just starting, it will not allow us to judge the severity of this incident, but it is precisely because of such incidents as this that we are looking at following the health of the river in this way.”
Yorkshire Water said they tested the Foss after reports of dead fish being seen and found nothing alarming.
A Yorkshire Water spokesperson said: “We did attend the area after the reports of the fish deaths and tested the water, which found no ammonia present, indicating no sewage discharges in the area.”
[tptn_list limit=3 daily=1 hour_range=1]