"treat the beaches as if you own them and give them the respect you would give what is yours."
I think that is the problem for some of the offenders Yoey, they are treating it like they own it. (really hate to see their own backyards...)
Seriously, along Whirinaki yesterday I counted at least 5 full dumped black rubbish bags, countless piles of garden waste which while at least that breaks down it still looks ugly and numerous plastic bags / bait bags. On other beaches however where there is ample rubbish bins (I'm not talking the one or two that is at Awatoto) people seem to use them. maybe the council could also step up and place more bins along well used beaches? That might clean it up a bit as well as signs saying dumping prohibited, offenders will be fined etc. The signs might not help much but if they stop at least 1 person then thats a start