While I was carrying out a urban breeding Yellow-legged Gull survey in the city of Lagos, Portugal in 2008, I was contacted by a Swedish team of ornithologists and doctors who wanted to know of good sites to collect gull pooh where I was working. They came down to Lagos and nearby Portimão fishing ports to collect samples - their aim was to detect antibiotics in the food chain via gulls. They drove down from Sweden in a van kitted out with a freezer to keep the samples below -40ºC, to be analysed in Sweden.
I never got any feedback regarding the results but I did get a thank-you.
So this problem has been studied for a while now.
Last edited by Simon Wates : Saturday 13th July 2019 at 14:14.