Anglers and members of the public are being asked to be vigilant over the next couple of months in a bid to prevent fish deaths.

The recent high temperatures and humid conditions can prove to be a lethal combination to fish stocks.

The main threat to stocks comes from a lack of oxygen, which can have a devastating effect on a fishery and in extreme cases can completely wipe out stocks.

Venues particularly prone to de-oxygenation in the York area include the River Foss and Pocklington Canal.

Heavily stocked stillwaters are also at risk where the high density of fish places extra demands on the water's oxygen reserves.

Richard Jenkins, fisheries science team leader with the Environment Agency, said: "We are asking the public and anglers to be extra vigilant and look out for any fish in distress or gasping at the surface.

"If they spot anything, especially early in the morning, they should immediately notify the owner or angling club.

"If that is not possible they should contact us as soon as they can.

"A quick response can easily save the lives of fish."

The two main causes of lack of oxygen are organic pollution and algal blooms. Algae are a common feature of many lakes and ponds and generally do not cause a problem but during the summer and autumn their rapid growth can cause problems, especially in shallow stillwaters.

The density of the algae, despite giving off plenty of oxygen by photosynthesis during the day, stops producing life-giving oxygen at night leading to rapid declines in the oxygen content of the water during the hours of darkness.

If the following day is dull and oxygen levels are not replenished the downward cycle can prove deadly.

The Agency recommends that angling clubs and owners of fisheries have emergency procedures in place.

These should include the ability to provide emergency aeration equipment, such as a pump or similar, in order to improve oxygen levels as soon as possible.

Further information and advice can be obtained from Environment Agency fisheries' departments.

If people need to report a pollution incident or fish in distress, they should use the emergency 24-hour hotline number on 0800 807060.

Meanwhile, tickets for the York Amalgamation Veterans' match which will once again be fished at Oaktree Leisure, Huby are now on sale priced £3.

The event - open to the over 60s - will be held next Wednesday. Tickets can be purchased from local tackle shops or direct from Terry Pinder on 01904 629126.

Tickets for other Amalgamation matches should soon be available and it is hoped that more extensive advertising and a reduced number of contests at favoured venues will see a reverse in the dwindling attendances.

Weekend bookings

Saturday: Fulford - Local; Acaster - GPO. Sunday: Park View - Ben Johnson; Killingbeck and Poppleton - CIU; Beningbrough Park - Bishopthorpe and Acaster; Acaster - Acomb WMC; Tockwith - White Rose; Skip Bridge - Pudsey; Kirkham - Poppleton; Paradise Farm - Huntington; Stamford Below - Cygnet.

Updated: 12:03 Friday, August 02, 2002