Basin Notes - March 2000

Year 2000 Service?

The proposals to build a wastewater treatment plant at Broomfield by the North of Scotland Water Authority (to comply with current EU legislation) will no doubt be welcomed by everyone. Especially so by those of us who have reluctantly come to appreciate the finer points of the "annual family constitutional", (swimming in the sea)!

It won't make the water any warmer but it should re- duce the number of encounters we have with those "unmentionables" that induce a greater fear than any shark could. The improved water quality of the river (with its higher levels of dissolved oxygen) should benefit species such as salmon and trout But will the Basin as a whole benefit from its "2000 year service"?

And talking of millenniums, what are the odds on the Basin still being here in another thousand years? Far reaching questions, but even though I probably won't be around to find out the answers to them, they still concern me.

Will the Basin as a whole benefit when sewage dis- charges are cleaned up?

The answer is probably yes, but as with any component change within an ecosystem, where there are winners there are inevitably going to be losers. The losers will probably be sewage feeding invertebrates, which are being maintained at unnaturally high levels, due to discharges of domestic sewage and agricultural run-off

There will be a knock on effect mainly among the many species of fish and birds that rely on this source of food The ramifications of a shutting down of this food supply could be truly global, owing to the fact that many of our winter visitors (apart from travelling from different continents) arrive here in internationally important numbers.

Combine this with the effect that global warming is pre- dicted to have on sea levels (a rise of up to 1 m over the next 50 years) and we could be looking at a senous situation for those birds that rely on the extensive areas of exposed mud like the Basin to provide them with food. With the Basin being classified as a micro-tidal estuary (having a tidal range of 0-2m) how much of this will remain above water in the future?

We can try to answer some of these questions by looking at similar situations, which have occurred elsewhere.

For instance, when the canning factory overlooking the river closed down several years ago, the large flock of mute swans that were attracted to the discharges of vegetable matter during the winter, were left with only three options: starve, revert to their original "hunter gatherer" type lifestyles (still largely adopted by their cousins the Whooper swans); or adopt the supermarket approach and help themselves to the best that was available (in this case the oilseed rape fields and winter cereal crops of local farmers).

They are still here today and are now a major headache for some farmers.

Another example of how things can go wrong when we tamper with natural systems that we don't fully understand is the Cardigan Bay development (not too dissimilar to the Basin) The harbour having been closed off to create a marina (denying winter feeding to thousands of birds) it has recently been emptied due to an excessive build up of pollutants.

Will the Basin still be here in another thousand years? I hope so.