Looks Can Be Deceiving: A River In Decline

Professor Richard Fortey stands in front of the River Thames in Henley

Greener Henley caught up with Richard Fortey, British palaeontologist, natural historian, writer, television presenter and long time Henley resident, to get his views on how the river has changed over the years… and what we can do about it.

Looks Can Be Deceiving: A River In Decline

By Professor Richard Fortey

“When you live close to the River Thames in a town like Henley for many years you come to know the river and its wildlife in an intimate way – you see the changes that happen over time in a fashion that the casual visitor will not be able to appreciate. Somebody who does not know the habitat in an intimate way might think that all is well – the ducks and geese gather around the boatyard as they always have, the river flows peacefully by, the willow trees lean over the eyot and all might seem happy with the environment. But a casual look can deceive. I have lived here long enough to realise the impact of the periodic episodes of pollution, produced by repeated releases of insufficiently processed sewage, releases that have intruded upon the livelihood of the wildlife on the river.  I first noticed this some years ago that the number of tiny fish – the ‘fry’ of fresh water species like perch – that used to abound in the shallows seemed to have disappeared. Then the submerged river plants either seemed to have disappeared or were covered by a slimy dark green coating of algae that were encouraged by higher levels of nitrogenous waste. Now we know that release of effluent during periods when processing capacity at sewage works is exceeded is almost certainly responsible for shocks to the habitat.

Professor Richard Fortey looks into the River Thames

I have lived here long enough to realise the impact of the periodic episodes of pollution, produced by repeated releases of insufficiently processed sewage, releases that have intruded upon the livelihood of the wildlife on the river. 

“The ecosystem of freshwater habitats is fragile, and periodic ‘shocks’ are not something that can be simply washed away when flow conditions are restored to normal.  The Thames has been home to iconic birds that rely on catching live fish – often small fry – and if the fish disappear go then the birds are forced to live elsewhere.  The great crested grebe was once both the favourite and most elegant bird on the river. When pollution struck they went upstream, and they are now much more occasional. Bird watchers are disappointed.

“Pretty tufted ducks have been quite common in the past, but you have to search hard to see them today.  A well-stocked river can support anglers, who used to be a common sight between Henley and Shiplake, but they seem to have gone the way of the grebes.  The return of a healthy river could support anglers once again –who have, ironically, been acute observers in the decline of our home stretch of water.  Those healthy looking geese are not affected by the decline in water quality as they are grazers on the grassy fields adjacent to the river and not dependent on the stream itself. They join mallard ducks in vying for the bread crusts brought by the public to entertain their children, and thus are more ‘pollution proof’. The general decline in biodiversity is abetted by the rank growth of riverside vegetation promoted by the ‘fertiliser effect’ produced by the pollution episodes – so now we have coarse groves of nettles along the riverside when once there were sedges, and the warblers that once lived among the reeds and grasses have also found alternative sites.

“Birds are only the most conspicuous animals affected by the decline in water quality that follow ‘spills’, but a commensurate decline in insect life is just as important. As to permanent effects, there are less well-known victims. The gravel bottoms of parts of the Thames are home to freshwater mussels that filter out nourishment from the passing current. Sewage of any kind is poison to these rare molluscs, and unlike birds they cannot simply relocate. They are very slow growing and anchored to one site. Nationally, they are in decline – as much as 95% of them have disappeared since 1964 according to the Natural History Museum. The Thames has been home to several species. They may not be the most glamorous victims, but they are all part of the biodiversity of a formerly rich and varied habitat. 

“This impoverishment of Nature in our waterways is a disgrace. ; here in Henley the river is the life-source of our town – indeed this is the ‘home of rowing’ – with much human recreation taking place on the water. We must do all we can to put a stop to the poisoning of our rivers, prioritise their health and end this environmental degradation.

The river is a habitat and an ecosystem, but we must not forget that we are part of this ecosystem too

“We are often left agreeing with the sentiment of such observations, but feel unsure of what we can do about it. Signing an open letter to ask all parliamentary candidates to support the Climate and Nature Bill (CAN Bill) is one thing that we can all do very easily. We must protect and restore Nature, including our river, and the CAN Bill sets out a framework for legislation that will do this, whichever government is in charge. No matter what our individual political leanings are, Nature, including our river ecosystems, urgently needs legislation and robust action, independent of party politics.”

Professor Richard Fortey OBE FRS FRSL
Resident of Henley-on-Thames

If you would like to sign up to the open letter asking all Henley and Thame election candidates to support the cross-party Climate and Nature (CAN) Bill in Parliament, you can find the link here.

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