What are the effects of the Lure and Luck of the Sea fishing pole enchantments, and how much does each higher level of the enchantments improve the effect?
From the MC Wiki http://minecraft.gamepedia.com/Enchanting#Enchantments
Luck of the Sea:
Decreases odds of catching worthless junk
Lowers chance of "junk" catches by 2.5% per level and increases chance of "treasure" catches by 1% per level.
In 1.9: Lowers chance of Junk and Increases chance of treasure by 2% per level. Reduces chance of fish by 0.15% per level.
Increases rate of fish biting your hook
Decreases time before fish bite your hook by 5 seconds per level. Also decreases chances of both "junk" and "treasure" catches by 1% per level.
In 1.9: no longer affects loot tables. There is no change in junk and treasure chances.