PVA reaction in salt water

[MTbowel]

My son is a fan of carp fishing. There is a popular method of carp fishing which involves tying the bait in anglers PVA netting or bags and casting the bag out into the lake. The PVA dissolves in the water fairly slowly releasing the bait at the prime spot where carp are present. Here's a good link:

http://www.carp-bait....etup/pva-systems.aspx

My son told me the other day that he can stop the bag from dissolving in water. He filled a small PVA bag with bait and dropped it into a soup bowl of water at home. The bag failed to dissolve in the water. After I was bewildered fro a suitable time, he told me his secret. He had added a small amount of table salt (sodium chloride) to the water. Now I know this is only a party trick and of no real use, can any of you scientists explain why a PVA bag fails to dissolve in saline?

Thanks.

[Laasya]

May the composition of water is different from the density of the water.

[MTbowel]

ehh?

[MTbowel]

Come on you scientists, you must have some idea about this one!