In this video I show how to create a simple net bag without using special tools or extravagant knots. This technique is same that I use to make a hand net. You can view those videos here: How to: Make Rustic Hand, Scoop, or Dip-Nets
This size net bag took approximately 200ft of store-bought jutte cordage. You can use any sort of durable natural fiver such as dogbane, nettle, milkweed, yucca, basswood, elm, etc...it just may take you a while to harvest and process the amount you would need...in a survival scenario it is about caloric input vs. caloric output.