Tag Archives: rivers

Vole patrol part 2

Surrey Wildlife Trust’s quest to find out if water voles are functionally extinct in the county continues. Which means I spent some of my bank holiday wading through a brook, looking for burrows, feeding signs, droppings and pawprints.

It was a beautiful day, and a beautiful site to survey. A small brook running through farmland, with earth cliff banks covered in brambles dripping with ripe blackberries. The stream itself didn’t have any vegetation in it, but the water was clear, the banks easily burrowable, and there was plenty of vegetation along the banks. So not entirely unlikely habitat for a water vole. In fact, we know there used to be voles here, hence we were surveying this site.

Tanners Brook
Tanners Brook

Charlotte (a fellow volunteer and my partner in crime for this survey) and I donned our waders, buoyancy aids and set off, stick and clipboard in hand. The survey involves one person wading in the river, looking for water vole signs (or mink, rat or otter for that matter), while the other keeps pace along the bank, drawing a map as she goes. We took it in turns to do the fun bit (the heat of the day made the cool water appealing, even though my waders were slightly leaky).

Disappointingly (but not surprisingly), we didn’t find any signs of water voles. There were a few holes too small for a water vole, and a few much to big. But not pringle tube sized holes, no vole droppings, no feeding lawns… I guess the good news is that we didn’t find any mink pawprints or droppings either.

Water vole populations have disappeared from 94% of their previous sites, the fastest decline of any British species. The last confirmed sighting of a water vole in Surrey was eight years ago. Surrey Wildlife Trust aim to survey around 200 sites where water voles have previously been reported. They’re also asking members of the public to report any water voles they spot in Surrey. There’s a handy ID guide on their website (which is useful as it’s easy to mistake a swimming rat for a water vole – in fact, the wonderful Ratty from The Wind in the Willows is actually a water vole).

The intrepid vole patrollers have so far surveyed 84 sites. But we haven’t found a single water vole sign. Plenty of mink. And rats. But no water voles.

The information from all these surveys will help Surrey Wildlife Trust work out how best to help water voles in the county. This may include predator (mink) control and possibly re-introductions, if there’s still enough  suitable habitat in our crowded county. Our neighbours, Hampshire, still have water voles. I hope one day we can see them in Surrey again.


Alien invaders: the Quagga mussel

News hot off the press: a new non-native invasive species has been discovered in Britain. This time it’s a small mussel, called the quagga mussel. It was spotted in Britain for the first time in Staines earlier this month.

The quagga mussel looks innocuous enough. They are much smaller than the type you get served in a moules mariniere. But they can cause lots of damage to the river biodiversity. They filter out lots of nutrients used by algae that compete with the notorious blue-green algae, allowing the toxic blue-green algae to flourish. The mussels can also cause damage to pipes and boat propellers by attaching themselves in great number (up to 10,000 per square metre) to them, causing blockages. They can alter the whole ecosystem.

There is no effective way of controlling or eliminating them once they are established, and they spread very quickly. This makes tackling the problem now, and preventing further spread vital.

So what can we do? Firstly, we need to look out for them, and report them if we find them. You can find details of how to identify and report them on the Non-native Species Secretariat website. The small army of river wardens in Surrey are on alert, and will be watching out for them when we do our next walkovers along the rivers Wey and Mole. We’re not that far from where they were found, so vigilance is important.

Secondly, everyone who makes use of our rivers, lakes, ponds, reservoirs and seas needs to be careful they’re not going to spread the mussels (or any other invasive species) accidentally. This includes anglers, kayakers, people who like messing about in boats, dog walkers and others. We can do this by following the Check – Clean – Dry routine:

1) Checking our clothes and equipment for live organisms hiding in the hard to see bits

2) Cleaning clothes and equipment thoroughly, leaving any live organisms at the waterbody you found them

3) Dry all equipment, and make sure you don’t transport any water.

You can read more advice about stopping the spread of the quagga mussel here.

I’ll let you know if I spot any on the River Mole next time I am Riversearching.

Beavers back in the wild

Last autumn, while staying on the banks of the River Otter, I was surprised to read a sign at the local mill listing beavers as well as otters and kingfishers as local wildlife highlights. In fact, I didn’t believe it.

I knew there were projects to reintroduce beavers into carefully enclosed areas of Scotland. But it turns out that the first beavers breeding in the wild for centuries in England are actually to be found in Devon. Camera trap footage has now recorded three individuals, including a young beaver, on the River Otter.

No one is quite sure where they’ve come from. It’s illegal to introduce beavers into the wild in England. While Devon Wildlife Trust are carrying out a pilot beaver reintroduction into an enclosed area, that’s at the opposite side of the county, and all their beavers are accounted for.

Personally speaking, I’m quite excited by the thought of beavers roaming free in England once more. But it is quite controversial. Beavers are by nature engineers – they shape the landscape they live in. Their dams can create pools where once there were woods and fields. If I were a landowner, I’d be concerned about the effects beavers may have.

The Mammal Society have recently suggested that beavers should be reintroduced to help reduce flooding. They are also thought to be beneficial to plant diversity, creating wetland areas. Their river engineering also creates good habitats for fish, invertebrates, amphibians, and some mammals and birds.

It’s going to be interesting to see what effect the beavers have on the River Otter, whether they breed and spread, and whether we can live peacefully with a wild creature that can dictate the course of rivers…

Making the most of the floods: gathering data to help prevent future flooding & pollution

If you live in the UK you’ll have noticed the storms over the last few weeks. The humble River Mole even made it onto the national news on Christmas eve as homes and businesses were flooded, and people left without power for days. The flooding is not just a human tragedy. Heavy rains, winds and floods increase pollution, and rising water levels can be fatal for riverside dwellers. That’s why, on the 5th January, in the rain, I donned my wellies and high vis jacket, and headed out along the river.

I’m one of Surrey Wildlife Trust’s volunteer river wardens, as part of RiverSearch. The scheme is a great idea – volunteers are allocated a stretch of river, and regularly monitor it for pollution, non-native invasive species and species like otters.

I’m ashamed to admit that since I did my training last autumn, I’d yet to do my first real survey. So when the email came from the coordinator, urging us to get out along rivers looking for pollution and flooding, I knew I had to act. I wouldn’t normally choose a rainy January afternoon for a stroll, nor a route along a river that has recently flooded. But those conditions do provide an excellent opportunity to spot where rivers are getting polluted from run-off from farmland or roads, and other sources of pollution.

Urban point source pollutionWater levels have receded on Pipp BrookSo off I set, armed with a camera, clipboard, gps and intrepid stick, and kindly accompanied by Dr C. In all, we covered just under 5 miles, although not all of that was along the river. Along Pipp Brook there were lots of places where urban run-off was entering the stream. The water level in the mill stream had fallen a couple of feet from the previous afternoon, but it was still much higher than normal. There were also lots of plastic bags and other debris stranded on overhanging branches, washed there by the high water or blown by the wind.

Spot the stepping stones?Out of town, by the Mole, the water level had receded a lot since Christmas, but was still flooding the bankside field and woods. There was no sign of the Stepping Stones at the foot of Box Hill.

The River Mole bursting its banksThe water was a murky brown from the washed-in mud, and visibility in the river must be close to zero. I felt sorry for the kingfisher I glimpsed zooming past, as hunting must be difficult in these conditions. Water voles can also be badly affected by flooding, as their bankside burrows can get flooded with the rising water. The additional nutrients washed into rivers are bad news for fish (and those creatures that depend on fish), as it can deplete oxygen levels in the water.

Hopefully the data gathered by the volunteer River Wardens can help to identify ways to reduce pollution and flooding along Surrey’s rivers for the future. And hopefully the weather will improve quickly to give all those (human and animal) who live by rivers and the sea a chance to recover.