We woke early one Saturday morning in order to join a guided wade along the rocky bed of Deptford Creek. All in the name of ecology, botany, history, and zoology. It was absolutely fascinating.

The Creekside Discovery Centre is a truly passionate charity dedicated to changing Londoners’ limited and most likely prejudiced perceptions of our urban rivers, in this case focussing on the River Ravensbourne and the tidal stretch where it empties into the Thames at Deptford Creek. They provide a range of activities based around Deptford, all designed to bring people into contact with nature and to raise ecological awareness.

The ornate gates of the Creekside Discovery CentreWe reached the Centre from Greenwich station in a few minutes, via the footpath beside the railway line. Upon arriving at the Centre we were met by the bearded font of bubbling enthusiasm that was our guide for the day, Nick. Watching my friend Mark from the Natural History Museum interact with Nick was a delight as they cheerfully goaded each other over the merits, or not, of gardening versus ‘translocating’ plants. Nick is tremendously proud of the brownfield habitat surrounding the centre with its tens of thousands of tiny rare Rue-leaved saxifrage (Saxifraga tridactylites) blooms peeping out into urban Deptford. He spends a fair bit of time spotting and saving (AKA translocating) unusual and threatened plants from the ongoing demolitions and supposed regenerations around this reach of London.

After our brief tour of the brownfield habitat we went back into the centre to don our rubber waders for our walk in the Creek. As you head inside there are racks literally overflowing with flotsam plucked from the river. On Mark’s last visit to the Centre he found a samurai sword in the water, heaven knows why that was in there but I don’t really want to ponder that for too long. There are also dozens of wallets strewn around the shelves, something I saw throughout the creek walk. I guess that a river provides the perfect place to discard a robbed wallet?

Heading down to the only beach on Deptford Creek

The River Ravensbourne rises from Caesar’s Well in Keston. It trickles slowly through Bromley and Beckenham to Catford, where it absorbs the smaller River Pool and forges north, ever swelling. Edging around Lewisham it ends its journey by emptying into the Thames at Deptford.

The Creekside Discovery Centre possesses the only ‘beach’ along the Creek. Meaning that there is a slope from above well above the waterline down to the riverbed. Obviously our visit was timed to take advantage of low tide so the beach was completely revealed. This gave Mark and Nick the chance to revel in the various plant nurseries supported by the frequently inundated soil.

The evident pride taken in their discoveries is infectious and I found myself keenly but ignorantly admiring their Haringey/Railway Knotweed (Fallopia x conollyana), one of the first half dozen specimens ever recorded. The lethal water hemlock surrounding the edges is something I’ve seen all over town. It looks innocuous but it is one of the most toxic plants known to man.

Both botanists effused over the Marsh Sow-thistle (Sonchus palustris) they pointed out beside the rubble path. This species has suffered enormously over recent years of development and human encroachment, and Mark has played a part in restoring it to the wild near Crayford Marshes where it was previously deliberately destroyed. It turns out that brownfield sites are a lot more interesting than I ever imagined.

The River Ravensbourne at Deptford Creek

We stepped down into the Creek for the first time and used our wooden walking poles to turn ourselves into tripods. Nick took the lead and off we went upstream. Much of the walk focuses on the efforts of the Creekside Discovery Centre staff getting to know the ecology of Deptford Creek. Their mistakes are often as interesting as their successes. For example, who would have thought that removing shopping trolleys from a river could cause a fish population collapse? Really it’s blindingly obvious, but perhaps only in hindsight. A river like this has almost no foliage at the water’s edge, just the sheer walls built from steel, stone, or wood. Shopping trolleys are perfect fish houses because the mesh lets little fish in whilst barring hungry predators from getting in. Removing the trolleys left the fish open to the daily raids of big fish when the tide came in. Cue population and biodiversity crashes.

Deptford Falls and the swan

Next up comes Deptford Falls. Or rather the very small weir just around the second bend. We carefully picked our path around the next curve, not so much because of the slippery rocks or the drowning potential but because a flipping furious swan was bristling itself at our approach. We inched around it as Nick tried to gently encourage it to move away from our party. I’ve never seen a bird so obviously angry before. Yes, Canada Geese frequently nip people at the slightest provocation but they appear to have a dumb kind of foolish and greedy rage, not the calculated show of strength that the swan was obviously preparing for us. Had there only been one of us I would not have been surprised if it had gone nuclear. Once we were safely past him Mr. Swan visibly relaxed but continued to train its beady eye on us.

An angry swan on Deptford Creek

The Creek walk cannot probe much further south than here because the Ravensbourne is culverted and protected by a much more impressive weir than the one that Mr. Swan was protecting. Here Nick pointed out to us the various ways that conservation can be carried out to alter an urban river’s ecology. The sheer steel walls on the far side were barren, whereas the stone and timber walls were draped with foliage. The Centre actively campaigns to have river walls fixed with wooden frames so that each high tide deposits both soil and flora on top of each beam. Here we could see the Herb Robert Flower with its glorious purple flower shining brightly against the dark stone backdrop. “Where you find decay you find life” stated Nick earlier in the walk – obviously truthfully. As wood rots it acts as a flowerpot and you get these little glimpses of beauty in what can be a harsh human landscape. Micro-habitats like these allow the river to be colonised rather than completely debased by human interaction.

The wooden frames on the walls of Deptford Creek help to preserve biodiversity

We had to double back past the swan again but this time it was not quite so concerned, thankfully. Two of our party had been prodding around in the riverbed and unearthed a large hunk of flint, when it came clear of the water we could see it teeming with life. Tiny shrimp wriggled all over the slimy surface but in the concave spaces we found various water snails sheltering. Mark took the flint and the snails off to the Natural History Museum with him.

Seconds later Nick was rummaging through the mud along the verge and called for us to gather around him. He had found leeches. Their mouth parts were too feeble to break human skin but they could still hang on to its surface and dangle from his raised hand. They extended themselves like living spaghetti, down and down, vainly searching for a more natural surface to cling to until they were about 4 inches long. Weird little things.

Leeches hanging off the hand of Nick Bertrand of the Creekside Discovery Centre, Deptford

I spotted a passport and several more wallets around here, kept company by gently bobbing golf balls presumably lost by players in Beckenham Place Park – 6 miles upstream from here.

Graffiti overlooking Deptford Creek

Back down by the beach we had a few minutes of using nets to see what we could haul out of the river. Resting them on the bed and then scraping your foot along the rocks would lead to dozens of shrimp filling the nets in seconds. We each filled the waiting plastic trays so that the water pulsed with darting shapes. I dragged an Asian clam out of the water, and then Nick located a Chinese Mitten Crab. These invasive species have all come into British eco-systems via the ballast water of shipping and now they are causing havoc. There is not much that can be done but to support our native wildlife to counter the threat.

Chinese Mitten crab found in Deptford Creek

We headed downstream from the beach for only a few minutes before we noticed that the tide was rapidly turning. As we plodded back to safety we could actually see the water level rising and areas of land we had just walked on being inundated. The importance of having a knowledgeable guide in these situations became self-evident.

As we packed up the nets and trays someone caught a Stickleback fish, and then the area’s abattoir past met the modern day as a wonderfully intact but totally black  (meaning really rather old) cow bone was dredged to the surface.

I had expected mud to play a lot more of a part in the day’s adventure but we had gotten off pretty lightly really. Only the odd splatter here and there. However, there was a group of Boy Scouts in the Creek at the same time as us but on a separate walk and one of them came past me a bit worse for wear.

“Why is it always me?” he mournfully asked, to nobody in particular. The scout leader decided to point out that it was because he never paid attention. The boy didn’t seem to hear that remark because he was too busy focussing on all the mud hanging off of his clothes and not still looking where he was going. Which made us laugh even more.

If you are interested in taking a guided walk in Deptford Creek then please contact the Creekside Discovery Centre. Remember that it is tide-dependent so you do need to book in advance. Today’s walk was the Low Tide Walk which is also suitable for children aged 8-16 (who I reckon would love this walk).

Rubber waders are provided to protect your clothes, feet, and legs from mud and sharp objects, but make sure you wear warm socks underneath as the two and a half hours in the water will eventually start to numb your toes. If you are anything like me though you won’t notice that – it’s just too interesting to care about your feet!