A reminder to Wellington dog walkers - watch out for toxic algae

The deadly substance has been spreading wide across the whole region due to recent hot weather, including rivers in Otaki, Waikanae, and Wairarapa.

In the Hutt River, algae's been spotted from Birchville, all the way to Melling.

Greater Wellington scientist Mark Heath says it's incredibly deadly for children and animals.

He says it's important that people know what it is and what it looks like, and if you're not sure - avoid it and keep your dog on a leash.