examinator: "Thanks for the info what I was referring to was the 'drop in an Olympic pool'."

Oh. Sorry. I admit that was a complete throw away line, as I have no idea what the relative magnitude of plastic bag consumption is. However, since you have challenged me on it, here is a back of the envelope calculation. It could easily be out by an order of magnitude.

Total shopping bag consumption per year in Australia for 2001: 38,850 tons. www.environment.gov.au/settlements/publications/waste/plastic-bags/pubs/analysis.pdf, page 5 para 2.

Total oil consumption in Australia per day in 2007: about 1,000,000 bbl. http://www.indexmundi.com/australia/oil_consumption.html Weight of a barrel of oil is approx 140 kg. http://wiki.answers.com/Q/How_much_does_1_barrel_of_crude_oil_weigh

Ergo, percent of oil the plastic bags represent by weight: 0.07%

I have no idea what fraction a drop represents in a swimming pool, but it will far, far less than 0.07%. I am hoping you will nonetheless concede me the point as 0.07% isn't relevant in the scheme of things. Besides, it is all a lie. I just found out the the favoured feed stock for plastic shopping bags is natural gas, not petroleum. http://en.wikipedia.org/wiki/Plastic_shopping_bag#Composition So maybe the oil drop in a swimming pool is not too far out after all.

examinator: "conversations by some is 'the all or nothing' approach"

True. But reading between the lines the link I posted above, the impact of plastic bags on marine life compared other plastic is so small it isn't measurable. In the mean time turn the nurseries of our oceans, the mangroves, into sea side resorts. Recreational boats dragging anchors degrade our reefs. Fishing nets turn lush marine grass fields into barren areas, killing all the dugongs that used to feed on them. We over fish our fisheries to the point of no return. And yet what do we propose to take drastic action over? Plastic shopping bags - something whose effects are barely measurable beyond the occasional bleeding heart photograph. For gods sake people, get a sense of proportion.

Hasbeen, very good point. I have never seen an animal caught up in plastic. Old netting, fishing line yes, but never plastic, although I don't disbelieve it happens.

I to have fished the whitsundays and strolled for several miles along the shores near weipa and rarely seen a plastic bag.

My list in order would be;
Bottles (without notes inside), plastic buckets, thongs (only ever one), netting, long line floats, but rarely ever plastic bags.

Your point is already acknowledge by me. Sadly the question was on plastic bags. There is no way I would deny that the greater risk is the other things but it is a case of *cumulative* effect. Therefore the the solution(s) will be as stated a cornucopia of small decisions. That is how we got in this mess.
I reject your bleeding heart reference on the same grounds.

Hasbeen
I have direct contact a number of organisations at the sea and research level. Plastic bags are large cause of marine deaths especially around the Qld coast. This is tragically true with breeding age turtles end gravid females.
In recent surveys the warming of their breeding sand is producing females given this gender imbalance and already high attrition rates from all the reasons Previously stated by rstuart, at the current rates turtles in local waters are in real trouble. The other problem is like the injured surfers surfing the really dangerous reefs “you don't see them”.
In the deep water the turtles sink and are eaten before they float.
I would suggest you and rehctub contact sea world at the gold coast and ask them.
NB. I am not intending to make a big issue about this but it IS far more common than people. One gasping/ choking turtle is a slow news day feature. And again there are other issues as well.I also acknowledged this maybe coloured a darker shade of grey because I'm closer to it. Think of it like this I drive a Subaru once you're sensitised to their existence it's amazing how many I see. Are they the biggest number amongst traffic no but they *do* contribute to the traffic problems too.

Fractelle, I did say most I acknowledge that you saw the bigger picture. Onya girl.:-)

examinator: "Sadly the question was on plastic bags."

Precisely. They question was "we are about to ban plastic bags ... [is this worth doing]." Well that is my paraphrase anyway.

When answering questions like this, I always try to quantise the problem - in other words assign numbers to it. The emotive appeal of a turtle with a plastic bag hanging out of its mouth is big, but I am suspicious things that appeal to emotions only. I guess that unease is neatly captured by "I feel, so you must change". Insisting on numbers helps separate the emotion from observable outcomes. Observable outcomes really do effect others. In the end your emotions rarely effect anyone but you.

Looking at the numbers I can find, my guess we will not be able to measure the effect of banning plastic bags. This is because in survey's I found of of animals killed by pollution, the authors didn't bother to mention "death by shopping bag" at all.

Nonetheless you apparently want to ban shopping bags because the death of the odd turtle worries you. Obviously it doesn't worry everybody quite so deeply, and some of them would prefer to keep their plastic bags. So the question becomes, does examinator get to force them from using plastic bags, even though there is no long term observable effect?

We have spoken about this before rechtubs views are close to mine on this issue.
Right now in country towns check out operators tell of people with goats siting in the back of Utes getting the green bags out from under them and walking into shops.
If the swine flue had or does hit us, if deaths come via it, do you want your neighbors bags next to your food?
Why are we focused on bags but have plastic bottles laying in every gutter and creek?
Make a law that lets you have one new plastic bag only for every one you return to shops.

I'll just add my bit to the interesting comments made so far.

Banning shopping bags is in Australia a minor move towards addressing the major issue of excessive packaging in this country. I am actually very surprised that any government in Australia is willing to impose such a ban in the face of the lobbying by vested interests against it. It is also only at most a minor inconvenience to shoppers. It sends a broader message out to the community so has some symbolic value I suppose.

Rwanda and I think Uganda banned these bags years ago because, I recall, they were being used to bury faeces and it was becoming normal to encounter such a package whenever earth was moved. Yuk!

Ireland levies a 15p charge on shopping bags which has proved very successful in reducing usage.

We are a wasteful society and anything we do to reduce that waste is welcome in my eyes but we have a long way to go. Why for instance when I buy aspirin are they only available as individually wrapped packages? Ten years ago when I bought my last lot I was able to get 100 in a little jar. We are in general moving in the wrong direction with packaging - more of it being used not less.