Falling oxygen levels are causing ‘fish kills’ in the Leeds and Liverpool Canal

ANGLERS, being allowed back once again to fish along the Leeds and Liverpool Canal in Craven following a relaxing of Government guidance during the coronavirus lockdown, are being asked to report incidents of fish distress and fatalities.

Walkers and cyclists are also being asked by the Canal and River Trust to report sightings of fish in distress caused by what it says is decreased levels of oxygen in the water.

The trust, the largest owner of fishing rights in the UK, has welcomed back anglers to its waterways for the first time in seven weeks.

They are however, only permitted to visit the canal if they are either alone, with members of their household, or with one other non-household member and importantly they can only fish where strict social distancing can be maintained.

Meanwhile, the trust says it has seen a staggering 300 per cent increase in the number of fish distress callouts compared to this time last year due to decreased levels of oxygen in the water.

Peter Birch, national environment policy advisor at the Canal and River Trust explained:

“Fish are sometimes overlooked by visitors to our canals, but they are integral to the ecosystem and a vital part of the wider food chain on our waterways. The joy of spotting a kingfisher, otter or heron is very much down to what’s going on below the water level.

“Fish are a great indicator of good water quality – if the fish are thriving, so will other waterway wildlife. The canals are generally healthier than ever and we’re keeping a close eye on the particular circumstances that are causing problems right now and taking action to support the fish.”

Instances of fish distress and fatalities – known as fish kills – occur when oxygen levels in the water decrease. The trust says the key factors causing this at the moment are:

  • High levels of sunlight during April helped algae blooms to flourish much earlier in the year than usual. The naturally occurring organisms grow in nutrient rich waters and are encouraged by warm weather and increased sunlight. Algae can cause water quality issues by reducing the amount of oxygen in the water during the night which, if left to its own devices, can impact on fish and other aquatic creatures.
  • And, a rise in pollutants in the waterways, from accidental spills or even deliberate illegal disposal of pollutants.

Because the conditions could persist throughout the lockdown, and as we approach the summer, the trust is asking people to help support it’s frontline operational teams and report any instances of fish in distress or any other unsociable behaviour on their towpaths or waterways.

John Ellis, the trust’s national fisheries and angling manager said: “Thanks to the public getting in touch we’ve been able to prevent two major incidents from escalating any further.

“With oxygen levels in the water on the Leeds and Liverpool Canal and the Lancaster Canal close to zero before we intervened, around 50,000 fish were estimated to be at risk of dying on each waterway.

“Thankfully we lost only 200 fish in total because we were able to intervene in time and increase oxygen levels in the water with aerators and pumps.”

He added: “Our fisheries and angling experts, ecologists and environmental scientists are all working closely with operational teams to look after our precious canals and rivers during this difficult time. With reduced staffing on the canals at present, the Trust’s operational teams are helping to monitor oxygen levels in some locations as a precaution, but we need the public and the angling community to help.

“We know how much people enjoy spending time by water, it helps us to relax, unwind and boost our happiness levels. If you are taking a short walk to your local waterway as part of your daily exercise, please keep an eye out and, if you see something unusual, then please contact our customer service team on 0303 040 4040.

“Fish gulping for air at the surface and not moving away with great haste when you approach them is a classic sign of serious distress. This is occasionally confused with fish gasping at the surface or basking close to the surface on warm sunny days but scattering when you approach,” he added.

The charity is also asking people to limit their use of canal towpaths and stay local. Everyone should abide by the government guidelines, share the space along the narrow towpaths, respect social distancing and reduce speed if cycling.

Source:  Craven Herald and Pioneer, 23rd May 2020