Tuesday 30 July 2013

A pile of poo





 One of the results of having so little rain on the island is that the sheer quantity of bird poo that falls on the island during the season is much more obvious because the rain hasn't washed it away. Until a few days ago when we had some big showers, the island was covered in white with the seabird cliff colonies gleaming bright white in the sun. Of course this shouldn't be a surprise as with 200,000 large birds all on a high protein diet living in a small space there is going to be a lot of poo. What these birds are doing are hoovering fish up from a very wide area, several hundred square miles around the island, growing chicks on the fish and squirting out the waste. This results in the energy production of the sea being concentrated onto the island and running off into the sea around. This does have an effect on the environment with a massive rearrangement of energy and chemicals,  for instance the UK seabirds emit 2700 tons of ammonia per year and are the largest point source of ammonia in the country. This doesn't really compared with the amount that farm animals produce across the UK but in remote areas where farming is less intensive seabirds are often the most significant source of ammonia.
On the island you can see these for once it does start to rain a slurry of liquid bird poo runs off the cliffs and forms clouds in the sea around.
We get used to it and don't notice the smell but it does affect life on the island. In peak puffin feeding time eating dinner outside can mean a liquid addition to your meal from above. And the rain water collected from the roof becomes what is really dilute bird poo and so isn't suitable for anything other than flushing loos. So a dramatic reduction in seabirds can have a knock on effect on other creatures and ecosystems that are adapted to live on this redistributed energy. You can never look at any one group of wildlife in isolation.
And less poo would remove one of our favourite occupations - spotting pictures and faces in the patterns from above!











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