Pure Guano!

Gulls appear to have been singled out on warning signs on Scottish beaches for their contribution to water pollution. These warnings ask people not to feed the gulls as this will only encourage the birds to defaecate (https://www.theguardian.com/uk-news/2022/jul/27/gull-poo-pollution-warnings-on-scottish-beaches-out-of-proportion-say-experts). Fairly obviously, a vast variety of fish, birds and mammals (including pet dogs) crap into the seas surrounding our coasts. Water companies even pump raw sewage out into these locations, when it rains hard. The contribution made by gull guano must be a relatively minor contribution. Salty sea water is also a pretty good disinfectant. The warnings do seem to be 'over the top'.