A little light googling reveals that there are people keeping an eye on our beaches, but it's a bit of a King Canute job. We love surfers against sewage, but they specialise in water and have their hands full with their local beach....but they are worth supporting
http://www.sas.org.uk/campaign/marine_litter/index.php
The maritime conservation society are also in on the act - once a year.
http://www.adoptabeach.org.uk/