Loch Lomond National Park has issued a warning to visitors after reports of blue-green algae in the water.

The Park Authority says they have received reports of sightings of the organisms, which are known to produce harmful toxins, around Balloch Park Slipway.

Posting on social media, visitors are warned to be careful as the blue-green algae can kill dogs and other animals.

The park wrote: "We have received reports of sightings of blue-green algae around Balloch Park Slipway.

"Blue-green algae can produce toxins that can kill dogs and other animals. In humans, it can cause rashes after skin contact and illnesses if swallowed.

"If you believe you have spotted blue-green algae, you can contact the environmental health team at your Local Authority. SEPA can also be contacted, or you can record it on the citizen science app - Bloomin Algae."

West Dunbartonshire has announced that its Environmental Health team have put up signage in the affected areas and says they will continue to monitor the situation.

The algae blooms can make the water in the loch become green, blue-green or greenish brown as well as forming odours and foam on the shoreline.

In advice issued by the park, they say they aim to advise visitors when the warning is over but it can be difficult to predict as it could form and dissipate again within hours or days.

Anyone who spots the algae is encouraged to report it on an app called Bloomin' Algae which reports the presence of the substance.