Save the Dolphins

I was in the town centre the other morning and went to buy some coffee beans. The shop that sells coffee beans, as apposed to the coffee shop (see earlier posting) is never that busy and as I went in I was the only customer. The woman assistant came over as I looked at the coffee and I selected Monsoon Malabar 500g just the beans.
These she poured onto the scales, which I am sure automatically go to 250 or 500g because they seem to be able to pour any amount in and bingo, it hits exactly the amount you asked for. The beans were then poured into a bag and sealed with tape. At the till I gave over my loyalty card and the required amount of money as she reached for a carrier bag.
"Don't worry about a bag I have one already Ill use, so long as you don't mind not getting the advertising". "Oh", blank look, "OK then". She handed me over the coffee and I put it in my carrier bag.
"We are all being told not to waste carrier bags, but I don't expect I'll save the planet" I Said.
"They are giving out paper bags in one shop" she replied "and in the co-op they are using bio-degradable ones"
"Really, I wonder how long they take to degrade?" I asked "Five years" She replied. She is obviously well into this I realised and wondered why she had tried to give me the unnecessary carrier in the first place.
"I hear that there is also a problem with sea creatures and dolphins eating carrier bags because they think they are jellyfish" I added.
"Really!?"
"Yes, although I think it would be easily solved, just add, under the bit that says plastic bags are dangerous don't let children play with them, large easily readable letters, I AM NOT A JELLYFISH"
She didn't reply. The shop seemed really quiet. I left quickly.