Blue-Green Algae in Scotland: What Every Wild Swimmer and Dog Owner Should Know

I love swimming in summer, long evenings, warmer water and those days when you can finish work and be in a loch twenty minutes later.

Unfortunately, we're not the only ones enjoying the sunshine.

Warm, calm weather can also bring blue-green algae.

If you're new to wild swimming, it's something you really need to know about.

First things first...

Despite the name, blue-green algae isn't actually algae.

It's a type of bacteria called cyanobacteria, and some blooms produce toxins that can make both people and animals seriously ill.

It isn't worth taking chances with.

What does it look like?

That's the frustrating bit.

It doesn't always look the same.

Sometimes it looks like someone has spilled green paint across the surface.

Sometimes it's more like pea soup.

Other times you'll see green streaks collecting along the shoreline or floating in sheltered corners of a loch.

The problem is, it isn't always obvious.

Some blooms are easy to spot, others aren't. If the water looks unusual, trust your instincts.

I'd much rather miss one swim than spend the next week wishing I'd chosen differently.

Where are you most likely to find it?

Blue-green algae loves warm, still water.

It's much more common in smaller lochs and ponds than it is in larger bodies of water.

My local swimming spot gets it most summers after a spell of warm weather.

When that happens, I don't stop swimming.I change the plan, I'll head for a bigger loch, where there's more water movement, or I'll go to the coast and find a tidal pool instead.

One of the joys of swimming in Scotland is that we've got choices.

Sometimes the safest decision is to swim somewhere else.

Algae is one reason to get in the habit of checking water quality before every swim (https://wildchanger.com/blogs/news/wild-swimming-water-quality-why-you-should-check-before-every-swim), not the only one. 

Some local authorities and SEPA (https://bathingwaters.sepa.org.uk/ also publish water quality and bathing water updates for monitored sites.) Neither is a substitute for looking at the water in front of you, but they're a useful second check if you're planning a trip to a spot you don't know well.

What happens if you swim in it?

Blue-green algae can produce toxins that affect people in different ways.

Swallowing contaminated water can cause sickness, vomiting, diarrhoea and stomach cramps. Even if you don't swallow any, the toxins can cause skin rashes, sore eyes, ear irritation and, in some cases, breathing problems if you're exposed to spray or spend time close to the water.

Most people recover, but the effects can be more serious for children, older adults and people with underlying health conditions.

The good news is that it's easy to avoid.

If the water doesn't look right, don't get in.

There will always be another swim.

What about dogs?

I take my wee dog for a swim most weeks.

She loves the water almost as much as I do, and now she's getting older it really seems to help her arthritis. Watching her charging into a loch with the zoomies is one of my favourite parts of the week.

But blue-green algae is a firm no.

Dogs are much more vulnerable than we are. They'll happily swim through it, drink the water, chase a stick and then lick their fur afterwards. That means they can take in a much higher dose of the toxins than we ever would.

Sadly, blue-green algae poisoning can be fatal, and it can happen very quickly.

If you think your dog has been in contaminated water:

• Get them out of the water immediately.

• Rinse their coat thoroughly with clean, fresh water.

• Stop them licking their fur.

• Contact your vet straight away, even if they seem fine. The sooner they're treated, the better.

When in doubt, don't risk it.

She'd much rather miss one swim than never have another.

My rule

Wild swimming is supposed to make us feel better, not poorly.

I've never regretted turning round and finding another swim.

I have, however, heard plenty of stories from people who wished they'd trusted their gut.

Scotland has thousands of incredible places to swim,if one loch doesn't look right today, another one probably will.

That's one of the reasons I built the Scotland Wild Swimming Map. It isn't there to tell you where blue-green algae is, because nobody can do that in real time. It's there to give you options. If your usual spot isn't suitable, you can quickly find somewhere else and still enjoy your swim.

https://wildchanger.com/pages/scotland-wild-swimming-map

 

If your favourite swim spot isn't on the map yet, let me know. I'll happily add it. The map has been built by the wild swimming community from day one, and every new suggestion makes it more useful for all of us.

Stay safe, trust your instincts, and remember, the water will still be there tomorrow.