EVEN DIRTIER WATER

Last month David Henshall looked at the state of our coastal waters and found that pollution was nothing new. This month he looks at the situation as it is today whilst introducing us all to a new word.

The M27 bridge and Swanwick marks the start of the Upper Hamble, a wonderful and undeveloped stretch of the river that is very sensitive to any environmental challenges. Yet currently the toxic mix of oil, rubber deposits and dust from brake linings that collect on the motorway flush straight down into the river. Image: David Henshall

As the clocks tick over at 2359:59 and Christmas Day becomes Boxing Day, the whole tone of the festive holiday subtly changes. For the lovers of the water, this means the focus can now shift from family gatherings around the dinner table to the opportunity to get back out afloat, be that a Christmas Cracker race at a local club, the start of the Sydney-Hobart or a motor off to a quiet anchorage to meet up with friends for a drink at anchor.

For the really hardy souls amongst us, there is the chance to blow away the Christmas overindulgence by joining in with one of the many Boxing Day plunges into the open water. As the saying goes, ‘whatever floats your boat’, except that this year, a number of the organised swims had to be cancelled.

It was not because the conditions were too extreme, far from it, as for much of the UK the Christmas break was mild but damp, with rain in many places. Instead, because it had rained, a number of water companies had once again taken the opportunity to discharge untreated sewage into their nearest water course.

In places, this Christmas outpouring of something other than festive goodwill had been so prolonged and with further rain forecast, some of the warnings suggested that the usual four days it would take for the water to be safe again for bathing in could end up being extended into the New Year.

Yet incredibly all this is fully legal, as the water industry is allowed to discharge almost unimaginable amounts of untreated sewage into our waterways and seas, often on the flimsiest of excuses. The result is that there are almost 15,000 outlets around the UK where this is happening.

When the Government’s postBrexit Environmental Bill was debated back in the autumn a majority of the Conservative MPs, including nearly all of those whose constituencies line the coast from West Dorset to East Sussex, voted for the continuation of the status quo. Facing an outburst of public anger, this was changed for a demand that the water companies reduce the discharges, but with nothing quantified and without the imposition of a timescale, there are as yet few signs of improvement in our water quality.

Just as in Part 1 of this series, we have to take a balanced view and make it clear that whilst the water companies have seen executive pay rocketing alongside generous dividends to shareholders, they are far from the only entities that should be in the dock – and not a marina dock either!

Bridging the divide One of the most stressed sailing areas for the yachting community is the Hamble River. Once passed a number of busy and popular marinas the river is crossed by the M27 road bridge. Either side of the bridge is the higher ground that defines the Hamble Valley, so when it rains, the water runs downhill towards the bridge, before being funnelled down in culverts then straight into the river.

Any deposits that build up on the road surface can therefore end up being carried down with each new rainfall, but there is an even bigger concern. The M27 is a very busy motorway that carries a great deal of commercial traffic, including a lot of tankers from the oil terminal at Hamble. It would be wrong to be alarmist, but if there were to be an accident and an oil spill, even before the emergency services started to hose everything down, the contents would be following the rainwater path, straight into the river.

As part of the M27 upgrade National Highways had pledged to come up with a better solution to ensure the safety of the river below, only to start backtracking on the grounds of costs. This has led Councillor Sean Woodward, who is Chair of the Hamble River Board, to warn that the current situation was an ‘ecological disaster waiting to happen’.

itrogen run o Even more worryingly is the realisation that in addition to the release of raw sewage and the toxic run-off from the roads, for more than 30 years there has been an even more insidious yet persistent attack on our local waters, as a result of what is called ‘nitrogen run-off’. Some 70 per cent of this is the result of more intensive use of chemical fertilizers in agriculture, which then washes down into streams and rivers and eventually into our coastal waters.

In something of a double whammy for our already stressed coastal waters, the problems arising from higher nitrate concentrations tend to be worse in the southern and eastern areas, where drier conditions and a heavier reliance on arable farming see the greatest dependence on fertiliser use. It might be easy to think of this as an abstract problem, but it has a very real impact on those who keep their boats afloat for the majority of the year.

An antifoul coating that should have the potential to last up to two full

Lifting and scrubbing off (or a visit to the scrubbing piles) is a messy, time consuming and increasingly expensive task, yet as the rate of weed growth increases, the frequency of getting the bottom cleaned may have to increase. Image: Colin Porteous / Shutterstock seasons can be quickly overwhelmed by the high growth rates of weed and barnacles in the nutrient rich waters around our marinas and anchorages. At the same time, some of the more effective antifouling paints were found to be highly toxic to the marine environment and were rightly banned.

The result has been an increase in the frequency of boats needing to be hauled out and washed/scrubbed off and you only have to look at a mooring buoy or the sides of a marina pontoon to see an amazing degree of growth, even in the colder months of winter.

Bacteria concerns Of course, with the danger of ambient temperatures rising, there is the risk that the even warmer waters will combine with the pollutants to bring about an even greater amount and diversity of growths. The shallow waters of Chichester Harbour are an ideal breeding ground, with sea-surface temperatures reaching 20°C, a fact that prompted a new series of tests that discovered some worrying additions to the harbour occupants.

We often think of pollution in terms of discarded plastic, or even sewage, but the presence of some new strains of the Vibrio bacteria that have never before been found in UK coastal waters is a genuine cause for concern. Vibrio bacteria comes in several varieties, which can cause ear problems for swimmers and skin infections, whilst another strain is a common cause of gastroenteritis. It is not just those on the water who are at risk but shellfish and other ‘filter feeders’ can be killed by the Vibrio bacteria, with their loss from the food chain having a huge impact on the rest of the wildlife.

Unchecked eutrophication Just as with the Covid pandemic, which has given us a whole new language, so the growing threat of pollutants to our coastal waters is rich in new words and phrases. Without action, terms such as nitrogen runoff cycles, dead zones and algae blooms will become more commonplace, but if there is one word that will surely end up creeping into our lexicon it will be ‘eutrophication’.

This might sound like a high-tech mouthful that will quickly be forgotten, except for the fact that this one word describes how the combination of all these various pollutants come together in our coastal waters, feeding an explosion of growth in weeds and other life forms that should not be there. On the face of it, this does not sound so bad, except for the fact that all this new organic activity robs the water column and all the species that rely on it of the life-giving oxygen they all depend upon.

Be you a paddleboarder, kayaker or powerboater, we all want the seas to be alive and rich in diversity, yet that risk of unchecked eutrophication could well result in some of our most cherished sailing areas becoming nothing more than our own ‘dead sea’.

Even on an antifouled hull, the rate of growth of weed and barnacles is increasing in the nutrient rich waters. Image: Colin Porteous / Shutterstock