Concern has been raised about the water levels of Loch Ness and the River Ness amid the protracted dry spell affecting Scotland and the UK.

Last month, the loch dropped to its lowest level since records began in 1990 and it is still categorised as being “low”.

Dry weather in recent weeks has led to the Scottish Environment Protection Agency (Sepa) issuing a water scarcity alert in parts of the country.

There are also claims that hyrdo-electric power schemes are affecting the water levels at Loch Ness, which by volume is the largest body of water in the UK.

Brian Shaw, director of Ness District Salmon Fishery Board, said there had been a “dramatic shrinkage in the size of the River Ness”.

He told the BBC: “These conditions are not normally good for angling.

“We’re so early in the year – we’re early summer – and already twice this year the River Ness has got to its lowest level at that particular time of year on record.”

He said there is a “huge amount of concern” about the health of the river.

Mr Shaw said pumped storage hydro near Foyers was also contributing to the low water levels.

Adrian Shine, the naturalist who has studied the loch for decades and designed the Loch Ness Exhibition, also noted the low levels.

He told the broadcaster: “I cannot remember the water levels in Loch Ness being so low as they are now, since 1989.

“I think it’s most notable in Urquhart Bay.

“There’s a smaller bay within that bay which is almost dry now and I don’t recall that even in ’89.”

On Friday, Sepa placed another area of the Highlands at “significant risk” of water scarcity due to the dry weather.

It said it is “extremely concerning” that levels around Loch Maree had dropped so early in the summer.

The environment watchdog also warned water scarcity in Scotland is “expected to escalate quickly” over the coming weeks due to the lack of rain and high temperatures.

Loch Ness, along with Loch Esk in Dumfriesshire, are currently facing “moderate scarcity”.

Nathan Critchlow-Watton, Sepa’s head of water and planning, said: “For the risk of water scarcity to have reached significant this early in the summer is extremely concerning and leaves no doubt that the next few months are going to be very challenging for all those who rely on the water environment to run their business.

“While water levels are critical in this part of the Highlands, we can see other areas of Scotland are on the same trajectory and it’s vital that businesses take steps now to maximise the resource available and prevent further environmental harm.”

The Scottish Government has previously said climate change is likely to affect the availability of water in some areas, but predicting exactly where can be difficult.