Lake Life

Gloomy Prospects for Lake Life

Tests carried out on the water in the University lake have revealed that aquatic life could be seriously endangered.

The chemical analysis was commissioned by `Vision' following concern at the number of dead fish and ducks seen floating near Derwent island.

Chemists were shocked to discover extremely high levels of nitrates at the bottom of the lake. This is thought to have been caused by a twenty-five year build-up of duck excrement and silt.

Although modest amounts of nitrates can be beneficial, the alkalinity of the lake water almost defies life to exist in it.

Another major cause for concern was the virtual non-existence of phosphates in the lake. These were untraceable in two of the sites tested and were present at a concentration of just one part per million near Derwent.

This finding helps to explain the marked lack of plant-life and the failure of all attempts to rectify this problem.

Fishermen have connected the low phosphate levels to another analysis which shows that, while many fish have stunted growth, there are also unnaturally large eels and carp alive in the lake.

One fisherman said that, ``The slow moving water, the lack of any plant-life and the fetid conditions on the lake floor mean that there is little oxygen for the fish that live in the lake.'' He explained that the larger fish have evolved because of their need for larger gills which can take in more oxygen.

Several fishermen who use the lake blamed many of the problems on the waterfowl. They claimed that fish eggs are eaten by the ducks and geese, which are now estimated to number over 370.

The University was criticised for allowing the wild fowl population to grow at the expense of aquatic life simply because the wildfowl provided a more obvious spectacle.

The results of the test commissioned by `Vision' have caused more people to question the adequacy of the University's lake management policy.

When asked how the lake ecology works, Professor Alister Fitter from the Biology department replied, ``Basically, it doesn't.''

He added that, ``Left alone, the lake would become a swampy are, grown over and populated with wader birds, within the next fifty to sixty years.''

Detailed report on page 3

Oxygen shortage plagues lake

The University lake, which covers about fifteen acres, was created in the mid-sixties and was believed at the time to be the largest man-made ornamental lake in Europe.

Only the `top lake' near Derwent and Heslington Hall has a natural base. Elsewhere, the swampy ground was dug up and a plastic sheet covered with gravel was laid down.

Originally, it was up to six feet deep in places, but the depth is now less than three feet due to the buildup of duck excrement and silt. Any flow of water is impeded by this reduced depth.

The lake is made cloudy in colour by the turbulence caused by rain or bird activity on the surface, which disturbs the silt on the lake floor. Occasionally, scum forms on the surface, especially near Spring Lane and this is removed by a sewerage disposal company.

At least three inlets serve the lake: One travels underneath the sports pitches from a field opposite Goodricke, and another comes from a York Waterworks drinking water sump.

There have been allegations that the third inlet, a beck which runs past Heslington Church, has been polluted by the Chemistry department. An outflow pipe near this area was seen to contain odorous organic pollutants which flowed into the beck.

However, the allegations were vigorously denied by laboratory technician, Paul Roscoe. ``The Chemistry department certainly does not pump waste into the lake,`` he said.

Dr Barry Thomas from the Lake and Grounds Committee suggested instead that the beck had been polluted during the building of the Science Park behind the Chemistry department. This would stem from the use of cement, gypsum and other lime based products associated with a large scale building project.

Professor Fitter also noted that there was a hot water outflow pipe by the Physics department, although he was unsure of its source. ``A small amount of hot water would make a trivial difference,'' he said. ``However, the way in which it is treated is a concern''.

Certain methods could apparently add traces of heavy metals such as mercury or cadmium to the lake

University authorities may also have been responsible for the lack of plant-life. During the 1970s, there was a large quantity of pondweed in the lake, but an effort was made to reduce its growth by treating it with aquacide.

Professor Fitter feared that this policy may have been overdone, causing the complete destruction of all pondweed. As a result, the lake now has very low oxygen levels, despite the supposedly oxygenating effects of the fountain.

Suggestions have been made as to how some of these problems could be alleviated. The National Rivers Authority recommended chemical treatment of the lake bed to reduce the amount of wildfowl excrement.

Another idea put forward is to excavate several deep areas of the lake to allow sediment to settle. This would provide areas of clear where plants could grow, thereby raising the oxygen content.

The University recently commissioned a landscape survey of the campus which resulted in the removal of several trees from the lakeside near the Biology department. It is hoped that this will reduce the leaf deposition into the lake.

Professor Fitter also stated that he would be arranging a study of lake ecology by first year students next year.

However Dr Thomas said that there were no plans for any large scale cleanup operations as they would be too expensive to implement.

Photos: Cynthia O'Murchu. Captions: A dead duck pictured near Derwent Island; Oxygen levels may be too low for fish survival

The following is taken from a York Vision article (01/08/2007):

We're In The Duck Shit

Worms, vomit and diarrhoea can be pretty hard to swallow. And yet the thought of jumping into the campus lake seems to have crossed all our minds at some point. Ingesting the lake's water could easily cause some very nasty illnesses, particularly given the level of bacteria shown in results released by the University last week.

Talk about drink responsibly. The results are in and the condition of the lake looks to be as grimy as you thought it might be.

Given the levels of E Coli present in the water in the most recent test results, there should be some concern. There is a probable 600 instances of the bacteria in every 100ml of the water around Central Hall - that's about three times more than the bathing standard set by the EU. It's certainly no swimming pool. The strains of E Coli are not necessarily the same as the fatal version that you get from a dodgy butcher, but they can still do you some harm. The most common illness will be diarrhoea, but you could even suffer liver damage with Weil's disease, or become sick with gastroenteritis. But then that shouldn't be surprising really, given that the bacteria come from the faeces of warm blooded animals, or as it's more commonly known: duck shit.

Sensibly, staff at the university will not go into the lake without protecting themselves first. Weil's disease is always part of the risk assessment. They wear at least chest-high waders, if not full body dry suits, so there is minimal contact with the water. They're also advised to shower on site afterwards because of the risks involved. If they develop a cold or flu very soon after, as is likely to happen if you get Weil's disease, then they'll be told to go to the doctors. If the illness is not treated it can make you extremely ill and even cause meningitis.

The University has known since March 2005, when they released the Environment Performance Action Plan, that the lake is in a state of hypertrophication. Or simply, too many things live in there. The results clearly reflect the presence of more faeces than is healthy, which not only leads to high levels of bacteria, but also an ecosystem which leaves the lake looking green, brown and sometimes even glowing. Gordon Eastham, the Grounds Maintenance Manager, described to me the problems with trying to manage such a huge eco-system. He explained: 'The main difficulty with the lake is that it's a relatively new body of water and it didn't have time to balance on its own.' From the word go there's been too many animals living in there. The truth is it's incredibly hard to control such a large body of water; 13 acres in total. The problem is excacbated by the imbalance in the eco-system and the highly organic matter which is constantly churned up. Gordon reasons this is 'why it greens up so much in the summer'.

The problem that staff are grappling with at the moment is the numbers of large fish; the carp and bream that live in the lake are hungry little buggers and they go round bottom-feeding and stirring up all the silt from the bottom. As a result, not only does the water look grimy, but it also stops light getting through so the problems of no vegetation continue. The eco-system of the lake on campus is so muddied that Gordon admitted: 'We just don't have time and resources to sort it out'. I could tell from talking to him that this was an extremely frustrating problem.

Since last year the Estates Services has been trying to get rid of the carp and bream. Now before the animal rights activists start erecting placards, this is not a euphemism for killing them. As it happens, Gordon informed me: 'We never kill any of the wildlife'. There are no culls, despite persistent rumours that they pack us off home at Christmas and then kill all those poor little ducks. The majority of the animals on the lake are wild and do not belong to the University, and so it would be illegal for them to kill them off anyway. Instead, the Environment Agency will take away 10% of the surplus fish and the rest will be sold off to the Angling Association and the like. The income will be used for work on the lake.

The staff at the university try to use biological methods to improve the ecosystem, instead of chemicals . So that they throw in sacks of barley straw to inhibit the algal bloom and make it look better; this is method that's been used by farmers for hundreds of years. All methods are generally natural and do tackle the problems of the eco-system, but there also seems to be a drive to make it more of an aesthetic feature.The balance the University negotiates is making it presentable - a selling point - and also making it a healthy body of water. Gordon finds the problems of the lake exasperating. conditions.

He bemoans: 'It should be the jewel in the crown, but it's just not.' The lake will never look quite right under its current conditions.

The murky depths might suggest it's a deep lake but this is a myth like the Mini-Cooper. The lake is in fact 4ft deep. There will, however, be years worth of rubbish chucked in there. 'You'd be quite fool hardy to take a dive in' , advises Gordon.

I asked him exactly what we'd have to do to get this problem sorted once and for all. The answer doesn't look hopeful. They would have to start again completely. The lake water would have to be drained and the amount of water be put somewhere else. The bottom of the lake would need to be dredged for 40 years of rubbish; the fish would need to be sold off and redistributed to other lakes. The wildlife would have to be discouraged, and the birds owned by the university, such as the black swans, would need to be sold. The planting would then have to begin around the lake and it would need to be dug deeper in several places. But what's the likelihood that all this would happen and the lake would still end up attracting too much wildlife?

Back in March, Richard Firn, once a senior biology lecturer at York, spoke to Vision about his concerns, calling the proposed new lake 'unsustainable'. According to him, the experts the university has spent huge amounts of money on consulting used climate data from the past 30 years - but our rapidly changing environment means that these figures are both irrelevant and completely unhelpful.

He questioned where the Hes East lake water will come from, since there is no running flow or source. As such, it will be sustained by rain water, but this has dangerous implications. Given that rainfall is likely to decrease as summer approaches, the result could be increased evaporation and huge environmental problems.

Plans for combating the likely shortfall include a system whereby runoff water is collected from nearby areas, such as Badger Hill. Again though, this is likely to be in abundance in winter, not summer when the need is going to be greatest.

There is no way out of the ecological problems we have now. The measures we make are a plaster on an amputation; it remains to be seen if the planning will produce a more heavenly water feature at Hes East. For the moment though we are left with a big green monster of a lake that smells, glows and is suspiciously green: very B-movie.

Related pages:

Problems with the lake
The Bales in the lake

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